Array ( [0] => {{Short description|Topical skin product that helps protect against sunburn}} [1] => {{Redirect|Sunblock|the electronic music group|Sunblock (band)|the Ball Park Music song|Sunscreen (song)}} [2] => {{Distinguish|text=[[indoor tanning lotion]], the suntan lotion which intensifies sun exposure}} [3] => {{Use mdy dates|date=June 2015}} [4] => {{Infobox medical intervention [5] => | name = Sunscreen [6] => | image = Sunscreen on back under normal and UV light.jpg [7] => | caption = Sunscreen on back under normal and UV light [8] => | alt = [9] => | pronounce = [10] => | synonyms = Sun screen, sunblock, sunburn cream, sun cream, block out{{cite web | url=http://www.cancerhelp.org.uk/help/default.asp?page=3007 | title=Preventing melanoma | publisher=Cancer Research UK | access-date=2009-09-22 | url-status=dead | archive-url=https://web.archive.org/web/20080522113412/http://www.cancerhelp.org.uk/help/default.asp?page=3007 | archive-date=May 22, 2008 | df=mdy-all }} [11] => | ICD10 = [12] => | ICD9 = [13] => | ICD9unlinked = [14] => | MeshID = [15] => | LOINC = [16] => | other_codes = [17] => | MedlinePlus = [18] => | eMedicine = [19] => }} [20] => [21] => '''Sunscreen''', also known as '''sunblock'''{{efn|Sunblock and sunscreen are often used as synonyms. However, the term "sunblock" is controversial and banned in the EU{{Cite web|url=https://www.ulprospector.com/knowledge/7288/pcc-eu-spf-regulations-labelling-and-claims/|title=EU SPF Regulations: Labelling and claims|first=Mojgan|last=Moddaresi|date=October 20, 2017|website=Prospector Knowledge Center}} and USA as it might lead consumers to overestimate the effectiveness of products so labeled.}} or '''sun cream''', is a [[photoprotection|photoprotective]] topical product for the [[Human skin|skin]] that helps protect against [[sunburn]] and prevent [[skin cancer]]. Sunscreens come as [[lotion]]s, sprays, gels, foams (such as an expanded foam lotion or whipped lotion{{Cite web |date=July 8, 2022 |title=WHIPPED FORMULATIONS WITH DESIRED SENSORY IMPACT |url=https://www.ic.gc.ca/opic-cipo/cpd/eng/patent/3023702/summary.html?query=whipped%2C+carpenter&type=basic_search |website=Canada Patent Data Base |access-date=July 8, 2022 |archive-date=July 8, 2022 |archive-url=https://web.archive.org/web/20220708152847/https://www.ic.gc.ca/opic-cipo/cpd/eng/patent/3023702/summary.html?query=whipped,+carpenter&type=basic_search |url-status=live }}), sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly [[sunglasses]], [[sunhat]]s and special [[sun protective clothing]], and other forms of photoprotection (such as [[umbrella]]s). [22] => [23] => Sunscreens may be classified according to the type of [[#Active_ingredients|active ingredient(s)]] present in the formulation ([[inorganic compound]]s or [[organic compound|organic molecules]]) as: [24] => [25] => * Mineral sunscreens (also referred to as physical), which use only [[inorganic compound]]s ([[zinc oxide]] and/or [[titanium dioxide]]) as active ingredients. These ingredients primarily work by absorbing UV rays but also through reflection and refraction.{{Cite journal |last1=Cole |first1=Curtis |last2=Shyr |first2=Thomas |last3=Ou-Yang |first3=Hao |date=2015-10-02 |title=Metal oxide sunscreens protect skin by absorption, not by reflection or scattering |journal=Photodermatology, Photoimmunology & Photomedicine |language=en |volume=32 |issue=1 |pages=5–10 |doi=10.1111/phpp.12214 |pmid=26431814 |s2cid=20695063 |issn=0905-4383|doi-access=free }}{{Cite journal |last1=Schneider |first1=Samantha L. |last2=Lim |first2=Henry W. |date=2018-11-16 |title=A review of inorganic UV filters zinc oxide and titanium dioxide |url=https://onlinelibrary.wiley.com/doi/10.1111/phpp.12439 |journal=Photodermatology, Photoimmunology & Photomedicine |language=en |volume=35 |issue=6 |pages=442–446 |doi=10.1111/phpp.12439 |pmid=30444533 |s2cid=53562460 |issn=0905-4383}} [26] => * Chemical sunscreens, which use organic molecules as active ingredients. These products are sometimes referred to as petrochemical sunscreens since the active organic molecules are synthesized starting from building blocks typically derived from petroleum.{{Cite web | vauthors = Dinardo J, Downs C |date=April 2021 |title=Failure to Protect: Do Sunscreens Prevent Skin Cancer in Humans? |url=https://www.researchgate.net/publication/352061297 |website=ResearchGate}} Chemical sunscreen ingredients also mainly work by absorbing the UV rays.{{Cite web | vauthors = Ko SA | date = September 2016 |title="Physical" vs. "chemical" sunscreens and other sunscreen myths |url=https://kindofstephen.com/physical-vs-chemical-sunscreens-myths/ |access-date=2022-01-09 |website=KindofStephen |archive-date=January 9, 2022 |archive-url=https://web.archive.org/web/20220109211351/https://kindofstephen.com/physical-vs-chemical-sunscreens-myths/ |url-status=live }} Over the years, some organic UV absorbers have been heavily scrutinised to assess their toxicity{{cite journal | vauthors = Tian L, Huang L, Cui H, Yang F, Li Y | title = The toxicological impact of the sunscreen active ingredient octinoxate on the photosynthesis activity of Chlorella sp | journal = Marine Environmental Research | volume = 171 | pages = 105469 | date = October 2021 | pmid = 34500299 | doi = 10.1016/j.marenvres.2021.105469 | s2cid = 237469500 | bibcode = 2021MarER.17105469T }} and a few of them have been banned in places such as Hawaii{{cite journal | vauthors = Suh S, Pham C, Smith J, Mesinkovska NA | title = The banned sunscreen ingredients and their impact on human health: a systematic review | journal = International Journal of Dermatology | volume = 59 | issue = 9 | pages = 1033–1042 | date = September 2020 | pmid = 32108942 | pmc = 7648445 | doi = 10.1111/ijd.14824 }} and Thailand{{cite journal | vauthors = Chatzigianni M, Pavlou P, Siamidi A, Vlachou M, Varvaresou A, Papageorgiou S | title = Environmental impacts due to the use of sunscreen products: a mini-review | journal = Ecotoxicology | volume = 31 | issue = 9 | pages = 1331–1345 | date = November 2022 | pmid = 36173495 | pmc = 9652235 | doi = 10.1007/s10646-022-02592-w | bibcode = 2022Ecotx..31.1331C }} for their impact on aquatic life and the environment. [27] => * Hybrid sunscreens, which contain a combination of organic and inorganic UV filters. [28] => [29] => Medical organizations such as the [[American Cancer Society]] recommend the use of sunscreen because it aids in the prevention of [[squamous cell carcinomas]].{{cite web|url=http://www.cancer.org/docroot/PED/content/ped_7_1_What_You_Need_To_Know_About_Skin_Cancer.asp|title=Skin Cancer - Skin Cancer Facts - Common Skin Cancer Types|website=www.cancer.org|url-status=dead|archive-url=https://web.archive.org/web/20080410204247/http://www.cancer.org/docroot/PED/content/ped_7_1_What_You_Need_To_Know_About_Skin_Cancer.asp|archive-date=April 10, 2008|df=mdy-all}} The routine use of sunscreens may also reduce the risk of [[melanoma]].{{EMedicine|article|1119992|Sunscreens and Photoprotection}} To effectively protect against all the potential damages of UV light, the use of broad-spectrum sunscreens (covering both [[Ultraviolet#Subtypes|UVA]] and [[Ultraviolet#Subtypes|UVB]] radiation) has been recommended. [30] => [31] => As of 2021, only zinc oxide and titanium dioxide are generally recognized as safe and effective [[Generally recognized as safe and effective|(GRASE)]] by the U.S. Food and Drug Administration (FDA),{{Cite journal |last=Research |first=Center for Drug Evaluation and |date=2021-11-16 |title=Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen |url=https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fda-posts-deemed-final-order-and-proposed-order-over-counter-sunscreen |journal=FDA |language=en}} as currently there is insufficient data to support recognizing petrochemical UV filters as safe. [32] => [33] => == History == [34] => [[File:Malagasy Woman (26905387615).jpg|thumb|[[Malagasy people|Malagasy]] woman from [[Madagascar]] wearing [[masonjoany]], a traditional sunscreen whose use dates back to the 18th century]] [35] => [[File:Thanaka girls.JPG|thumb|Burmese girls wearing ''[[thanaka]]'' for sun protection and cosmetic purposes]] [36] => Early civilizations used a variety of plant products to help protect the skin from sun damage. For example, [[ancient Greeks]] used olive oil for this purpose, and [[ancient Egypt]]ians used extracts of rice, jasmine, and lupine plants whose products are still used in skin care today.{{cite book | vauthors = Nadim S |title=Sunscreens : regulations and commercial development |date=2005 |publisher=Taylor & Francis |isbn=978-0824757946 | veditors = Shaath N |edition=3rd |location=Boca Raton, Fl. |chapter=Sunscreen Evolution |name-list-style=vanc}} Zinc oxide paste has also been popular for skin protection for thousands of years.{{cite book |title=2000 Years of Zinc and Brass |vauthors=Craddock PT |publisher=British Museum |year=1998 |isbn=978-0-86159-124-4 |page=27}} Among the nomadic sea-going [[Sama-Bajau people]] of the [[Philippines]], [[Malaysia]], and [[Indonesia]], a common type of sun protection is a paste called ''[[borak (cosmetic)|borak]]'' or ''[[borak (cosmetic)|burak]]'', which was made from water weeds, rice and spices. It is used most commonly by women to protect the face and exposed skin areas from the harsh tropical sun at sea.{{cite web | vauthors = Tilmantaite B |date=20 March 2014 |title=In Pictures: Nomads of the sea |url=http://www.aljazeera.com/indepth/inpictures/2014/03/pictures-nomads-sea-2014312760932684.html |access-date=22 December 2014 |publisher=Al Jazeera |archive-date=October 2, 2018 |archive-url=https://web.archive.org/web/20181002083416/https://www.aljazeera.com/indepth/inpictures/2014/03/pictures-nomads-sea-2014312760932684.html |url-status=live }} In [[Myanmar]], [[thanaka]], a yellow-white cosmetic paste made of ground bark, is traditionally used for sun protection. In [[Madagascar]], a ground wood paste called [[masonjoany]] has been worn for sun protection, as well as decoration and insect repellent, since the 18th century, and is ubiquitous in the Northwest coastal regions of the island to this day.{{Citation | vauthors = Randrianarivony TN, Rakotoarivelo NH, Randriamalala JR |title=Ethnobotany of Madagascar |date=2022-11-15 |work=The New Natural History of Madagascar |pages=237 |publisher=Princeton University Press |isbn=978-0-691-22940-9 |doi=10.2307/j.ctv2ks6tbb.34 }}{{Cite web | author = Miora |date=2020-09-06 |title=Le masque au Santal |url=https://www.madavoyages.com/le-masque-au-santal |access-date=2023-07-04 |website=Mada Voyages |language=fr-FR}} [37] => [38] => The first ultraviolet B filters were produced in 1928.{{cite journal | vauthors = Ma Y, Yoo J | title = History of sunscreen: An updated view | journal = Journal of Cosmetic Dermatology | volume = 20 | issue = 4 | pages = 1044–1049 | date = April 2021 | pmid = 33583116 | doi = 10.1111/jocd.14004 | s2cid = 231928055 }} Followed by the first sunscreen, invented in Australia by chemist H.A. Milton Blake, in 1932{{Cite book | chapter = Photoprotection | vauthors = Lim HW, Thomas L, Rigel DS | veditors = Rigel DS, Weiss RA, Lim HW, Dover JS | chapter-url=https://books.google.com/books?id=RvCINU2hOHAC&q=milton+blake+sunscreen&pg=PA74 |title=Photoaging |pages=73–74 |date=2004-01-30 |publisher=CRC Press |isbn=978-0-8247-5209-5 |language=en}} formulating with the UV filter 'salol' (Phenyl salicylate) at a concentration of 10%.{{Cite book | veditors = Rigel DS, Weiss RA, Lim HW, Dover JS |url=https://books.google.com/books?id=RvCINU2hOHAC |title=Photoaging |date=2004-01-30 |publisher=CRC Press |isbn=978-0-8247-5209-5 |language=en}} Its protection was verified by the [[University of Adelaide]].{{Cite web |title=7 Wonders of South Australia winners: Innovations - ABC (none) - Australian Broadcasting Corporation |url=https://www.abc.net.au/local/stories/2014/07/23/4051703.htm |access-date=2021-07-06 |website=www.abc.net.au |archive-date=September 15, 2022 |archive-url= https://web.archive.org/web/20220915024051/https://www.abc.net.au/local/stories/2014/07/23/4051703.htm |url-status=live }}{{Cite web |title=History Of Hamilton |url=https://www.hamiltonsunandskin.com.au/history-of-hamilton |access-date=2021-07-06 |website=Hamilton |language=en-US |archive-date=July 9, 2021 |archive-url=https://web.archive.org/web/20210709185940/https://www.hamiltonsunandskin.com.au/history-of-hamilton |url-status=live }} In 1936, [[L'Oreal]] released its first sunscreen product, formulated by French chemist [[Eugène Schueller]]. [39] => [40] => The US military was an early adopter of sunscreen. In 1944, as the hazards of sun overexposure became apparent to soldiers stationed in the Pacific tropics at the height of [[World War II]],{{cite web | vauthors = Lim HW |title=Quantum Leaps: New, Improved Sunscreens Have Arrived |url=http://www.skincancer.org/prevention/sun-protection/sunscreen/Quantum-Leaps-New-Improved-Sunscreens-Have-Arrived |url-status=unfit |archive-url=https://web.archive.org/web/20120414193648/http://www.skincancer.org/prevention/sun-protection/sunscreen/Quantum-Leaps-New-Improved-Sunscreens-Have-Arrived |archive-date=April 14, 2012 |publisher=[[The Skin Cancer Foundation]]}}{{cite web | vauthors = Wang SQ, Hu JY |title=Challenges in Making an Effective Sunscreen |url=http://www.skincancer.org/publications/the-melanoma-letter/summer-2012-vol-30-no-2/effective-sunscreen |access-date=2014-06-12 |publisher=The Skin Cancer Foundation |archive-date=June 27, 2014 |archive-url=https://web.archive.org/web/20140627205141/http://www.skincancer.org/publications/the-melanoma-letter/summer-2012-vol-30-no-2/effective-sunscreen |url-status=live }}{{cite journal | vauthors = Maceachern WN, Jillson OF | title = A Practical Sunscreen -- "RED VET PET" | journal = Archives of Dermatology | volume = 89 | issue = 1 | pages = 147–150 | date = January 1964 | pmid = 14070829 | doi = 10.1001/archderm.1964.01590250153027 }} Benjamin Green, an airman and later a [[pharmacist]] produced Red Vet Pet (for red veterinary petrolatum) for the US military. Sales boomed when [[Coppertone]] improved and commercialized the substance under the [[Coppertone girl]] and [[Bain de Soleil]] branding in the early 1950s. In 1946, [[Austria]]n chemist Franz Greiter introduced a product, called ''Gletscher Crème'' (Glacier Cream), subsequently became the basis for the company Piz Buin, named in honor of [[Piz Buin|the mountain]] where Greiter allegedly received the sunburn.{{cite book |title=Sunscreens: Regulations and Commercial Development, Third Edition |publisher=Taylor & Francis Group |year=2005 |veditors=Shaath NA}}{{cite news |date=June 23, 2010 |title=Sunscreen: A History |newspaper=The New York Times |url=https://www.nytimes.com/2010/06/24/fashion/24skinside.html |access-date=July 24, 2014 |archive-date=November 11, 2020 |archive-url=https://web.archive.org/web/20201111205356/https://www.nytimes.com/2010/06/24/fashion/24skinside.html |url-status=live }}{{cite web |title=Gletscher Crème |url=http://www.pizbuin.com/v1/en/brand_story.html |archive-url=https://web.archive.org/web/20100512061324/http://www.pizbuin.com/v1/en/brand_story.html |archive-date=2010-05-12 |access-date=2013-06-29 |work=2010-04-22 |publisher=Piz Buin}} [41] => [42] => In 1974, Greiter adapted earlier calculations from Friedrich Ellinger and Rudolf Schulze and introduced the "sun protection factor" (SPF), which has become the global standard for measuring UVB protection.{{cite book |url=https://books.google.com/books?id=g-YCKEPYMpYC&pg=PA6 |title=Photodermatology |publisher=CRC Press |year=2007 |isbn=9781420019964 |veditors=Lim HW, Hönigsmann H, Hawk JL |page=6 |access-date=July 24, 2014}} It has been estimated that ''Gletscher Crème'' had an SPF of 2. [43] => [44] => Water-resistant sunscreens were introduced in 1977, and recent development efforts have focused on overcoming later concerns by making sunscreen protection both longer-lasting and broader-spectrum (protection from both UVA & UVB rays), more environmentally friendly,{{cite journal | vauthors = Scheele A, Sutter K, Karatum O, Danley-Thomson AA, Redfern LK | title = Environmental impacts of the ultraviolet filter oxybenzone | journal = The Science of the Total Environment | volume = 863 | pages = 160966 | date = March 2023 | pmid = 36535482 | doi = 10.1016/j.scitotenv.2022.160966 | s2cid = 254818408 | bibcode = 2023ScTEn.863p0966S }} more appealing to use and addressing the safety concerns of petrochemical sunscreens, i.e. FDA studies showing their systematic absorption into the bloodstream.{{Cite journal |last=Research |first=Center for Drug Evaluation and |date=2022-12-16 |title=An update on sunscreen requirements: The deemed final order and the proposed order |url=https://www.fda.gov/drugs/news-events-human-drugs/update-sunscreen-requirements-deemed-final-order-and-proposed-order |journal=FDA |language=en}} [45] => [46] => == Health effects == [47] => {{See also|Health effects of sunlight exposure}} [48] => [49] => === Benefits === [50] => Sunscreen use can help prevent [[melanoma]]{{cite journal | vauthors = Kanavy HE, Gerstenblith MR | title = Ultraviolet radiation and melanoma | journal = Seminars in Cutaneous Medicine and Surgery | volume = 30 | issue = 4 | pages = 222–228 | date = December 2011 | pmid = 22123420 | doi = 10.1016/j.sder.2011.08.003 }}{{cite book|title=World Cancer Report 2014.|date=2014|publisher=World Health Organization|isbn=978-9283204299|pages=Chapter 5.14}}{{cite journal | vauthors = Azoury SC, Lange JR | title = Epidemiology, risk factors, prevention, and early detection of melanoma | journal = The Surgical Clinics of North America | volume = 94 | issue = 5 | pages = 945–62, vii | date = October 2014 | pmid = 25245960 | doi = 10.1016/j.suc.2014.07.013 }} and [[squamous cell carcinoma]], two types of [[skin cancer]].{{cite journal | vauthors = Burnett ME, Wang SQ | title = Current sunscreen controversies: a critical review | journal = Photodermatology, Photoimmunology & Photomedicine | volume = 27 | issue = 2 | pages = 58–67 | date = April 2011 | pmid = 21392107 | doi = 10.1111/j.1600-0781.2011.00557.x | s2cid = 29173997 }} There is little evidence that it is effective in preventing [[basal cell carcinoma]].{{cite journal | vauthors = Kütting B, Drexler H | title = UV-induced skin cancer at workplace and evidence-based prevention | journal = International Archives of Occupational and Environmental Health | volume = 83 | issue = 8 | pages = 843–854 | date = December 2010 | pmid = 20414668 | doi = 10.1007/s00420-010-0532-4 | bibcode = 2010IAOEH..83..843K | s2cid = 40870536 }} [51] => [52] => A 2013 study concluded that the diligent, everyday application of sunscreen could slow or temporarily prevent the development of wrinkles and sagging skin.{{cite journal | vauthors = Hughes MC, Williams GM, Baker P, Green AC | title = Sunscreen and prevention of skin aging: a randomized trial | journal = Annals of Internal Medicine | volume = 158 | issue = 11 | pages = 781–790 | date = June 2013 | pmid = 23732711 | doi = 10.7326/0003-4819-158-11-201306040-00002 | url = http://annals.org/article.aspx?articleid=1691732 | access-date = June 6, 2013 | url-status = live | s2cid = 12250745 | archive-url = https://web.archive.org/web/20150404204739/http://annals.org/article.aspx?articleid=1691732 | archive-date = April 4, 2015 }} The study involved 900 [[light skin|white]] people in Australia and required some of them to apply a broad-spectrum sunscreen every day for four and a half years. It found that people who did so had noticeably more resilient and smoother skin than those assigned to continue their usual practices. A study on 32 subjects showed that daily use of sunscreen (SPF 30) reversed [[photoaging]] of the skin within 12 weeks and the amelioration continued until the end of the investigation period of one year.{{cite journal | vauthors = Randhawa M, Wang S, Leyden JJ, Cula GO, Pagnoni A, Southall MD | title = Daily Use of a Facial Broad Spectrum Sunscreen Over One-Year Significantly Improves Clinical Evaluation of Photoaging | journal = Dermatologic Surgery | volume = 42 | issue = 12 | pages = 1354–1361 | date = December 2016 | pmid = 27749441 | doi = 10.1097/DSS.0000000000000879 | s2cid = 37092409 }} Sunscreen is inherently anti-ageing as the sun is the number one cause of premature ageing; it therefore may slow or temporarily prevent the development of wrinkles, dark spots, and sagging skin. [53] => [54] => [[File:Sunbum sunscreen spf 30.jpg|thumb|upright|A tube of SPF 30 sunscreen on sale in the United States]] [55] => [56] => Minimizing UV damage is especially important for children and fair-skinned individuals and those who have [[Photosensitivity in humans|sun sensitivity]] for medical reasons.{{cite web|url=http://ohioline.osu.edu/cd-fact/pdf/0199.pdf |archive-url=https://web.archive.org/web/20080512053158/http://ohioline.osu.edu/cd-fact/pdf/0199.pdf |url-status=dead |archive-date=2008-05-12 | vauthors = Dresbach SH, Brown W |title=Ultraviolet Radiation |work=Ohioline Fact Sheet Series |volume=CDFS-199-08 |publisher=Ohio State University Extension |date=2008 }} [57] => [58] => === Risks === [59] => In February 2019, the US [[Food and Drug Administration]] (FDA) started classifying already approved UV filter molecules into three categories: those which are [[generally recognized as safe and effective]] (GRASE), those which are non-GRASE due to safety issues, and those requiring further evaluation.{{Cite journal |last1=Sabzevari|first1=Nina|last2=Qiblawi|first2=Sultan|last3=Norton|first3=Scott A.|last4=Fivenson|first4=David|date=2020-05-26 |title=Sunscreens: UV filters to protect us: Part 1: Changing regulations and choices for optimal sun protection|journal=International Journal of Women's Dermatology|language=en |volume=7 |issue=1 |pages=28–44 |doi=10.1016/j.ijwd.2020.05.017|pmid=33537394 |pmc=7838247 }} As of 2021, only zinc oxide and titanium dioxide are recognized as GRASE.{{Cite journal | author = Center for Drug Evaluation and Research |date=2021-11-16 |title=Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen |url=https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fda-posts-deemed-final-order-and-proposed-order-over-counter-sunscreen |journal=FDA |language=en}} Two previously approved UV filters, para-aminobenzoic acid (PABA) and trolamine salicylate, were banned in 2021 due to safety concerns. The remaining FDA approved active ingredients were put in the third category as their manufacturers have yet to produce sufficient safety data — despite the fact that some of the chemicals have sold in sunscreen products for more than 40 years. Some researchers argue that the risk of sun-induced skin cancer outweighs concerns about toxicity and mutagenicity,{{cite journal | vauthors = Nepalia A, Singh A, Mathur N, Kamath R, Pareek S, Agarwal M | title = Skincare Products as Sources of Mutagenic Exposure to Infants: An Imperative Study Using a Battery of Microbial Bioassays | journal = Archives of Environmental Contamination and Toxicology | volume = 80 | issue = 2 | pages = 499–506 | date = February 2021 | pmid = 33523258 | doi = 10.1007/s00244-021-00814-6 | bibcode = 2021ArECT..80..499N | s2cid = 231746171 }}{{Cite web | vauthors = Brown J |title=Sunscreen: What science says about ingredient safety |url=https://www.bbc.com/future/article/20190722-sunscreen-safe-or-toxic |access-date=2023-08-02 |website=www.bbc.com |language=en}} although environmentalists say this ignores "ample safer alternatives available on the market containing the active ingredient minerals zinc oxide or titanium dioxide" which are also safer for the environment.{{Cite web | vauthors = Ige D, Char E |title=State of Hawaii, Department of Health, Testimony Commenting on hb1519, Relating to Sunscreen, House Committee on Energy & Environmental Protection |url=https://www.capitol.hawaii.gov/sessions/Session2022/Testimony/HB1519_TESTIMONY_EEP_02-08-22_.PDF | date = 8 February 2022 }} [60] => [61] => Regulators can investigate and ban UV filters over safety concerns (such as [[Para-aminobenzoic acid|PABA]]), which can result in withdrawal of products from the consumer market.{{cite journal | vauthors = Lim HW, Mohammad TF, Wang SQ | title = Food and Drug Administration's proposed sunscreen final administrative order: How does it affect sunscreens in the United States? | journal = Journal of the American Academy of Dermatology | volume = 86 | issue = 2 | pages = e83–e84 | date = February 2022 | pmid = 34606770 | doi = 10.1016/j.jaad.2021.09.052 | s2cid = 238355497 | doi-access = free }} Regulators, such as the TGA and the FDA, have also been concerned with recent reports of contamination in sunscreen products with known possible human carcinogens such as [[benzene]] and [[benzophenone]].{{Cite web |title=Sunscreens - ensuring products are effective and safe for the 2021-22 summer |url=https://www.tga.gov.au/news/news/sunscreens-ensuring-products-are-effective-and-safe-2021-22-summer |website=TGA (Therapeutic Goods Administration)|date=June 21, 2022 }} Independent laboratory testing carried out by Valisure found benzene contamination 27% of the sunscreens they tested, with some batches having up to triple the FDA's conditionally restricted limit of 2 parts per million (ppm).{{Cite web |title=Valisure |url=https://www.valisure.com/valisure-newsroom/valisure-detects-benzene-in-sunscreen |access-date=2023-09-01 |website=www.valisure.com |language=en}} This resulted in a voluntary recall by some major sunscreen brands that were implicated in the testing, as such, regulators also help publicise and coordinate these voluntary recalls.{{Cite web | author = Center for Drug Evaluation and Research |date=2023-01-30 |title=Edgewell Personal Care Issues Voluntary Nationwide Recall of Banana Boat Hair & Scalp Sunscreen Due to the Presence of Benzene |url=https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/edgewell-personal-care-issues-voluntary-nationwide-recall-banana-boat-hair-scalp-sunscreen-due |access-date=2023-09-01 |website=www.fda.gov |language=en}} VOC's (Volatile Organic Compounds) such as benzene, are particularly harmful in sunscreen formulations as many active and inactive ingredients can increase permeation across the skin.{{cite journal | vauthors = Pal VK, Lee S, Kannan K | title = Occurrence of and dermal exposure to benzene, toluene and styrene in sunscreen products marketed in the United States | journal = The Science of the Total Environment | volume = 888 | pages = 164196 | date = August 2023 | pmid = 37201845 | doi = 10.1016/j.scitotenv.2023.164196 | pmc = 10330564 | bibcode = 2023ScTEn.888p4196P | pmc-embargo-date = August 25, 2024 }} Butane, which is used as a propellant in spray sunscreens, has been found to have benzene impurities from the refinement process.{{cite news |title=What is benzene, and why does it keep causing beauty product recalls? |url=https://www.washingtonpost.com/wellness/2023/02/01/benzene-aerosol-recalls-sunscreen-shampoo/ |access-date=3 September 2023 |newspaper=The Washington Post |date=1 February 2023}} [62] => [63] => Recent research by the FDA on six common petrochemical UV filters ([[avobenzone]], [[oxybenzone]], [[octocrylene]], [[homosalate]], [[2-Ethylhexyl salicylate|octisalate]], and [[octyl methoxycinnamate|octinoxate]]) found that they could be detected on the skin, in blood, in breast milk and in urine samples weeks after a single use.{{cite journal | vauthors = Matta MK, Florian J, Zusterzeel R, Pilli NR, Patel V, Volpe DA, Yang Y, Oh L, Bashaw E, Zineh I, Sanabria C, Kemp S, Godfrey A, Adah S, Coelho S, Wang J, Furlong LA, Ganley C, Michele T, Strauss DG | display-authors = 6 | title = Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial | journal = JAMA | volume = 323 | issue = 3 | pages = 256–267 | date = January 2020 | pmid = 31961417 | pmc = 6990686 | doi = 10.1001/jama.2019.20747 }}{{cite journal | vauthors = Schlumpf M, Reichrath J, Lehmann B, Sigmundsdottir H, Feldmeyer L, Hofbauer GF, Lichtensteiger W | title = Fundamental questions to sun protection: A continuous education symposium on vitamin D, immune system and sun protection at the University of Zürich | journal = Dermato-Endocrinology | volume = 2 | issue = 1 | pages = 19–25 | date = January 2010 | pmid = 21547144 | pmc = 3084961 | doi = 10.4161/derm.2.1.12016 }} [64] => [65] => There is a risk of an allergic reaction to sunscreen for some individuals, as "Typical allergic contact dermatitis may occur in individuals allergic to any of the ingredients that are found in sunscreen products or cosmetic preparations that have a sunscreen component. The rash can occur anywhere on the body where the substance has been applied and sometimes may spread to unexpected sites."{{Cite web |url=https://www.dermnetnz.org/topics/sunscreen-allergy/ |title=Sunscreen allergy |website=DermNet NZ |access-date=2019-09-17 |archive-date=October 31, 2020 |archive-url=https://web.archive.org/web/20201031201843/https://www.dermnetnz.org/topics/sunscreen-allergy/ |url-status=live }} [66] => [67] => ==== Vitamin D production ==== [68] => There are some concerns about potential [[vitamin D deficiency]] arising from prolonged use of sunscreen.{{cite journal | vauthors = Pfotenhauer KM, Shubrook JH | title = Vitamin D Deficiency, Its Role in Health and Disease, and Current Supplementation Recommendations | journal = The Journal of the American Osteopathic Association | volume = 117 | issue = 5 | pages = 301–305 | date = May 2017 | pmid = 28459478 | doi = 10.7556/jaoa.2017.055 | s2cid = 19068865 | doi-access = free }}{{Cite web|date=2017-05-03|title=Sunscreen may cause vitamin D deficiency, says study|url=https://www.medicalnewstoday.com/articles/317278|access-date=2021-10-27|website=www.medicalnewstoday.com|archive-date=October 27, 2021|archive-url=https://web.archive.org/web/20211027150118/https://www.medicalnewstoday.com/articles/317278|url-status=live}} The typical use of sunscreen does not usually result in vitamin D deficiency; however, extensive usage may.{{cite journal | vauthors = Norval M, Wulf HC | title = Does chronic sunscreen use reduce vitamin D production to insufficient levels? | journal = The British Journal of Dermatology | volume = 161 | issue = 4 | pages = 732–736 | date = October 2009 | pmid = 19663879 | doi = 10.1111/j.1365-2133.2009.09332.x | s2cid = 12276606 }} Sunscreen prevents ultraviolet light from reaching the skin, and even moderate protection can substantially reduce vitamin D synthesis.{{cite journal | vauthors = Holick MF | title = Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease | journal = The American Journal of Clinical Nutrition | volume = 80 | issue = 6 Suppl | pages = 1678S–1688S | date = December 2004 | pmid = 15585788 | doi = 10.1093/ajcn/80.6.1678S | doi-access = free }}{{cite journal | vauthors = Sayre RM, Dowdy JC | title = Darkness at noon: sunscreens and vitamin D3 | journal = Photochemistry and Photobiology | volume = 83 | issue = 2 | pages = 459–463 | year = 2007 | pmid = 17115796 | doi = 10.1562/2006-06-29-RC-956 | s2cid = 23767593 }} However, adequate amounts of vitamin D can be obtained via diet or supplements.{{Cite web|date=2017-10-23|title=Vitamin D|url=https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/|access-date=2022-02-17|website=nhs.uk|language=en|archive-date=December 22, 2021|archive-url=https://web.archive.org/web/20211222112245/https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/|url-status=live}} Vitamin D overdose is impossible from UV exposure due to an equilibrium the skin reaches in which vitamin D degrades as quickly as it is created.{{cite journal | vauthors = Holick MF |date=February 2002 |title=Vitamin D: the underappreciated D-lightful hormone that is important for skeletal and cellular health |journal=Current Opinion in Endocrinology, Diabetes and Obesity |volume=9 |issue=1 |pages=87–98 |doi=10.1097/00060793-200202000-00011|s2cid=87725403 }}{{cite journal | vauthors = Holick MF | title = Sunlight and vitamin D: both good for cardiovascular health | journal = Journal of General Internal Medicine | volume = 17 | issue = 9 | pages = 733–735 | date = September 2002 | pmid = 12220371 | pmc = 1495109 | doi = 10.1046/j.1525-1497.2002.20731.x }}{{cite journal | vauthors = Holick MF | title = Vitamin D deficiency | journal = The New England Journal of Medicine | volume = 357 | issue = 3 | pages = 266–281 | date = July 2007 | pmid = 17634462 | doi = 10.1056/NEJMra070553 | s2cid = 18566028 }} [69] => [70] => Studies have shown that sunscreen with a high UVA protection factor enabled significantly higher vitamin D synthesis than a low UVA protection factor sunscreen, likely because it allows more UVB transmission.{{Cite web|url=https://www.genengnews.com/news/are-vitamin-d-levels-jeopardized-by-sunscreen/|title=Are Vitamin D Levels Jeopardized by Sunscreen?|date=2019-05-10|website=GEN - Genetic Engineering and Biotechnology News|access-date=2019-05-18|archive-date=November 8, 2020|archive-url=https://web.archive.org/web/20201108002757/https://www.genengnews.com/news/are-vitamin-d-levels-jeopardized-by-sunscreen/|url-status=live}}{{cite journal | vauthors = Young AR, Narbutt J, Harrison GI, Lawrence KP, Bell M, O'Connor C, Olsen P, Grys K, Baczynska KA, Rogowski-Tylman M, Wulf HC, Lesiak A, Philipsen PA | display-authors = 6 | title = Optimal sunscreen use, during a sun holiday with a very high ultraviolet index, allows vitamin D synthesis without sunburn | journal = The British Journal of Dermatology | volume = 181 | issue = 5 | pages = 1052–1062 | date = November 2019 | pmid = 31069787 | pmc = 6899952 | doi = 10.1111/bjd.17888 | s2cid = 148570356 }} [71] => [72] => == Measurements of protection == [73] => [[File:Sunburn blisters.jpg|thumb | Sunscreen helps prevent [[sunburn]], such as this, which has blistered.]] [74] => [75] => === Sun protection factor and labeling {{anchor | Sun Protection Factor | Sun protection factor}} === [76] => [[Image:UV and Vis Sunscreen.jpg|thumb |upright=1.35 | Two photographs showing the effect of applying sunscreens in visible light and in UVA. The photograph on the right was taken using [[ultraviolet photography]] shortly after application of sunscreen to half of the face.]] [77] => [78] => The sun protection factor (SPF rating, introduced in 1974) is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, "SPF 15" means that {{frac|1|15}} of the burning radiation will reach the skin, assuming sunscreen is applied evenly at a thick [[#Dosage|dosage]] of 2 milligrams per square centimeter{{Cite news|url=https://www.surfnation.com.au/blogs/news/sunscreen-the-comprehensive-guide-to-sunscreen-in-australia|title=Sunscreen: The comprehensive guide to sunscreen in Australia|work=Surf Nation|access-date=2018-06-24|language=en|archive-date=November 27, 2020|archive-url=https://web.archive.org/web/20201127051116/https://www.surfnation.com.au/blogs/news/sunscreen-the-comprehensive-guide-to-sunscreen-in-australia|url-status=live}} (mg/cm2). It is important to note that sunscreens with higher SPF do not last or remain effective on the skin any longer than lower SPF and must be continually reapplied as directed, usually every two hours.{{cite web |url=http://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens |title=Sunscreen FAQs |publisher=American Academy of Dermatology |access-date=July 22, 2014 |archive-url=https://web.archive.org/web/20140721190111/http://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens |archive-date=July 21, 2014 |url-status=dead |df=mdy-all }} [79] => [80] => The SPF is an imperfect measure of skin damage because invisible damage and skin malignant melanomas are also caused by [[ultraviolet A]] (UVA, wavelengths 315–400 or 320–400 [[nanometre|nm]]), which does not primarily cause reddening or pain. Conventional sunscreen blocks very little UVA radiation relative to the nominal SPF; broad-spectrum sunscreens are designed to protect against both UVB and UVA.{{cite journal | vauthors = Stege H, Budde M, Grether-Beck S, Richard A, Rougier A, Ruzicka T, Krutmann J | title = Sunscreens with high SPF values are not equivalent in protection from UVA induced polymorphous light eruption | journal = European Journal of Dermatology | volume = 12 | issue = 4 | pages = IV-VI | year = 2002 | pmid = 12118426 }}{{cite journal | vauthors = Haywood R, Wardman P, Sanders R, Linge C | title = Sunscreens inadequately protect against ultraviolet-A-induced free radicals in skin: implications for skin aging and melanoma? | journal = The Journal of Investigative Dermatology | volume = 121 | issue = 4 | pages = 862–868 | date = October 2003 | pmid = 14632206 | doi = 10.1046/j.1523-1747.2003.12498.x | doi-access = free }}{{cite journal | vauthors = Moyal DD, Fourtanier AM | title = Broad-spectrum sunscreens provide better protection from solar ultraviolet-simulated radiation and natural sunlight-induced immunosuppression in human beings | journal = Journal of the American Academy of Dermatology | volume = 58 | issue = 5 Suppl 2 | pages = S149–S154 | date = May 2008 | pmid = 18410801 | doi = 10.1016/j.jaad.2007.04.035 }} According to a 2004 study, UVA also causes [[DNA repair#DNA damage|DNA damage]] to cells deep within the skin, increasing the risk of [[malignant melanoma]]s.{{cite journal | vauthors = Berneburg M, Plettenberg H, Medve-König K, Pfahlberg A, Gers-Barlag H, Gefeller O, Krutmann J | title = Induction of the photoaging-associated mitochondrial common deletion in vivo in normal human skin | journal = The Journal of Investigative Dermatology | volume = 122 | issue = 5 | pages = 1277–1283 | date = May 2004 | pmid = 15140232 | doi = 10.1111/j.0022-202X.2004.22502.x | doi-access = free }} Even some products labeled "broad-spectrum UVA/UVB protection" have not always provided good protection against UVA rays.{{cite news |url=http://www.nbcnews.com/id/12081374/ |title=Sunscreen makers sued for misleading claims |agency=Associated Press |date=April 24, 2006 |access-date=January 5, 2015 |archive-date=June 8, 2019 |archive-url=https://web.archive.org/web/20190608221941/http://www.nbcnews.com/id/12081374/ |url-status=live }} [[Titanium dioxide]] probably gives good protection, but does not completely cover the UVA spectrum, as early 2000s research suggests that zinc oxide is superior to titanium dioxide at wavelengths 340–380 nm.{{cite journal | vauthors = Pinnell SR, Fairhurst D, Gillies R, Mitchnick MA, Kollias N | title = Microfine zinc oxide is a superior sunscreen ingredient to microfine titanium dioxide | journal = Dermatologic Surgery | volume = 26 | issue = 4 | pages = 309–314 | date = April 2000 | pmid = 10759815 | doi = 10.1046/j.1524-4725.2000.99237.x | s2cid = 39864876 }} [81] => [82] => Owing to consumer confusion over the real degree and duration of protection offered, labelling restrictions are enforced in several countries. In the [[European Union|EU]], sunscreen labels can only go up to SPF 50+ (initially listed as 30 but soon revised to 50).{{cite journal | url=http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32006H0647:EN:NOT | title=Commission Recommendation of 22 September 2006 on the efficacy of sunscreen products and the claims made relating thereto | journal=Official Journal of the European Union | date=2006-09-22 | access-date=2009-09-25 | archive-date=February 22, 2014 | archive-url=https://web.archive.org/web/20140222055637/http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32006H0647:EN:NOT | url-status=live }} [[Australia]]'s [[Therapeutic Goods Administration]] increased the upper limit to 50+ in 2012.{{cite web | url=http://www.arpansa.gov.au/uvrg/rginfo_p13.cfm | title=UV Resource Guide - Sunscreens | publisher=Arpansa | date=2008-12-20 | access-date=2009-09-25 | url-status=dead | archive-url=https://web.archive.org/web/20091119074507/http://www.arpansa.gov.au/uvrg/rginfo_p13.cfm | archive-date=November 19, 2009 | df=mdy-all }}{{cite web | url=http://www.cancer.org.au/preventing-cancer/sun-protection/preventing-skin-cancer/spf50sunscreen.html | title=SPF50+ Sunscreen | date=2013-02-01 | access-date=2014-02-06 | archive-date=February 7, 2014 | archive-url=https://web.archive.org/web/20140207205843/http://www.cancer.org.au/preventing-cancer/sun-protection/preventing-skin-cancer/spf50sunscreen.html | url-status=live }} In its 2007 and 2011 draft rules, the US [[Food and Drug Administration]] (FDA) proposed a maximum SPF label of 50, to limit unrealistic claims.{{cite web|url=https://www.fda.gov/cder/drug/infopage/sunscreen/qa.htm|title=Questions and Answers on the 2007 Sunscreen Proposed Rule|website=[[Food and Drug Administration]]|url-status=dead|archive-url=https://web.archive.org/web/20080921135529/https://www.fda.gov/CDER/drug/infopage/sunscreen/qa.htm|archive-date=September 21, 2008|df=mdy-all}}{{cite web | url=https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm | title=Questions and Answers: FDA announces new requirements for over-the-counter (OTC) sunscreen products marketed in the U.S. | website=[[Food and Drug Administration]] | date=2011-06-23 | access-date=2012-04-10 | archive-date=April 23, 2019 | archive-url=https://web.archive.org/web/20190423132658/https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm | url-status=live }}{{cite journal |title=Revised Effectiveness Determination; Sunscreen Drug Products for Over-the-Counter Human Use |journal=[[Federal Register]] |date=June 17, 2011 |volume=76 |issue=117 |pages=35672–35678 |url=https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/UCM313542.pdf |access-date=November 21, 2013 |author=Department of Health and Human Services: Food and Drug Administration |archive-date=February 22, 2017 |archive-url=https://web.archive.org/web/20170222152537/https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/UCM313542.pdf |url-status=live }} (As of February 2017, the FDA has not adopted the SPF 50 limit.{{cite journal|url=https://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/ucm072134.htm|title=Status of OTC Rulemakings - Rulemaking History for OTC Sunscreen Drug Products| author = Center for Drug Evaluation and Research|journal=FDA|date=April 23, 2019|access-date=April 11, 2017|archive-date=November 9, 2020|archive-url=https://web.archive.org/web/20201109033819/https://www.fda.gov/drugs/status-otc-rulemakings/rulemaking-history-otc-sunscreen-drug-products|url-status=live}}) Others have proposed restricting the active ingredients to an SPF of no more than 50, due to lack of evidence that higher dosages provide more meaningful protection.{{cite web | url=http://onpoint.wbur.org/2011/06/16/sunscreen | date=2011-06-16 | access-date=2012-04-10 | title=Sunscreen Takes Some Heat: New Dangers, New Rules | archive-date=July 5, 2012 | archive-url=https://web.archive.org/web/20120705232835/http://onpoint.wbur.org/2011/06/16/sunscreen | url-status=live }} Different sunscreen ingredients have different effectiveness against UVA and UVB.{{cite web|title=The Burning Facts|url=https://www.epa.gov/sites/production/files/documents/sunscreen.pdf|access-date=1 December 2017|date=2006|archive-date=November 12, 2020|archive-url=https://web.archive.org/web/20201112023944/https://www.epa.gov/sites/production/files/documents/sunscreen.pdf|url-status=live}} [83] => [84] => [[Image:erythemal action spectrum.svg|thumb|upright=1.35 | UV sunlight spectrum (on a summer day in the Netherlands), along with the CIE Erythemal action spectrum. The effective spectrum is the product of the former two.]] [85] => [86] => The SPF can be measured by applying sunscreen to the skin of a volunteer and measuring how long it takes before sunburn occurs when exposed to an artificial sunlight source. In the US, such an ''[[in vivo]]'' test is required by the FDA. It can also be measured ''[[in vitro]]'' with the help of a specially designed [[spectrometer]]. In this case, the actual [[transmittance]] of the sunscreen is measured, along with the degradation of the product due to being exposed to sunlight. In this case, the transmittance of the sunscreen must be measured over all wavelengths in sunlight's UVB–UVA range (290–400 nm), along with a table of how effective various wavelengths are in causing sunburn (the ''erythemal action spectrum'') and the standard intensity [[spectrum]] of sunlight (see the figure). Such ''in vitro'' measurements agree very well with ''in vivo'' measurements.{{Attribution needed|date=September 2016}} [87] => [88] => Numerous methods have been devised for evaluation of UVA and UVB protection. The most-reliable spectrophotochemical methods eliminate the subjective nature of grading [[erythema]].{{cite journal | vauthors = Moyal D | title = How to measure UVA protection afforded by sunscreen products. | date = June 2008 | volume = 3 | issue = 3 | pages = 307–13 | doi = 10.1586/17469872.3.3.307 | url = http://www.medscape.com/viewarticle/576849 | journal = Expert Review of Dermatology | access-date = August 17, 2016 | archive-date = July 13, 2017 | archive-url = https://web.archive.org/web/20170713165717/http://www.medscape.com/viewarticle/576849 | url-status = live }} [89] => [90] => The ultraviolet protection factor (UPF) is a similar scale developed for rating fabrics for [[sun protective clothing]]. According to recent testing by ''[[Consumer Reports]]'', UPF ~30+ is typical for protective fabrics, while UPF ~20 is typical for standard summer fabrics.{{cite journal |url=http://www.consumerreports.org/cro/magazine/2014/07/what-to-know-about-sunscreen-before-buying-it/ |title=What to Know About Sunscreen Before Buying It |journal=Consumer Reports |date=May 2014 |access-date=December 20, 2014 |archive-date=October 12, 2019 |archive-url=https://web.archive.org/web/20191012144703/https://www.consumerreports.org/sun-protection/get-the-best-sun-protection/ |url-status=live }} [91] => [92] => Mathematically, the SPF (or the UPF) is calculated from measured data as:{{citation needed|date=July 2019}} [93] => [94] => \mathrm{SPF} = \frac{\int A(\lambda) E(\lambda)d\lambda}{\int A(\lambda) E(\lambda)/\mathrm{MPF}(\lambda) \, d\lambda}, [95] => [96] => where E(\lambda) is the [[solar irradiance]] spectrum, A(\lambda) the erythemal action spectrum, and \mathrm{MPF}(\lambda) the monochromatic protection factor, all functions of the wavelength \lambda. The MPF is roughly the inverse of the transmittance at a given wavelength.{{citation needed|date=July 2019}} [97] => [98] => The above means that the SPF is not simply the inverse of the transmittance in the UVB region. If that were true, then applying two layers of SPF 5 sunscreen would always be equivalent to SPF 25 (5 times 5). The actual combined SPF may be lower than the square of the single-layer SPF. [99] => [100] => === UVA protection === [101] => [102] => ==== Persistent pigment darkening ==== [103] => The persistent pigment darkening (PPD) method is a method of measuring UVA protection, similar to the SPF method of measuring sunburn protection. Originally developed in Japan, it is the preferred method used by manufacturers such as [[L'Oréal]]. [104] => [105] => Instead of measuring [[erythema]], the PPD method uses UVA radiation to cause a persistent darkening or tanning of the skin. Theoretically, a sunscreen with a PPD rating of 10 should allow a person 10 times as much UVA exposure as would be without protection. The PPD method is an ''[[in vivo]]'' test like SPF. In addition, the European Cosmetic and Perfumery Association (''Colipa'') has introduced a method that, it is claimed, can measure this ''[[in vitro]]'' and provide parity with the PPD method.{{cite web|url=http://www.colipa.com/site/index.cfm?SID=15588&OBJ=28546&back=1 |title=Method for the in vitro determination of uva protection provided by sunscreen products, 2007a |website=www.colipa.com |date=June 9, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080609221030/http://www.colipa.com/site/index.cfm?SID=15588&OBJ=28546&back=1 |archive-date=June 9, 2008 }} [106] => [107] => ==== SPF equivalence ==== [108] => [[File:UVA logo.svg|thumb | upright=0.5 | The UVA seal used in the [[European Union|EU]] ]] [109] => [[File:SPF15SunBlock.JPG|thumb|upright| A tube of SPF 15 sun lotion]] [110] => As part of revised guidelines for sunscreens in the EU, there is a requirement to provide the consumer with a minimum level of UVA protection in relation to the SPF. This should be a UVA protection factor of at least 1/3 of the SPF to carry the UVA seal.{{cite web|url=https://www.cosmeticseurope.eu/using-cosmetics-colipa-the-european-cosmetic-cosmetics-association/sun-products/the-european-commission-recommendation-on-the-efficacy-of-sunscreen-products.html|title=www.cosmeticseurope.eu|url-status=dead|archive-url=https://web.archive.org/web/20140826114843/https://www.cosmeticseurope.eu/using-cosmetics-colipa-the-european-cosmetic-cosmetics-association/sun-products/the-european-commission-recommendation-on-the-efficacy-of-sunscreen-products.html|archive-date=August 26, 2014|df=mdy-all}} The 1/3 threshold derives from the European Commission recommendation 2006/647/EC.{{Cite web |last=Cosmetics Europe |date=February 2009 |title=N° 23 IMPORTANT USAGE AND LABELLING INSTRUCTIONS FOR SUN PROTECTION PRODUCTS |url=https://www.cosmeticseurope.eu/files/9814/6408/4022/CR-23-Sunscreens_Labelling.pdf |archive-url=https://web.archive.org/web/20220305123301/https://www.cosmeticseurope.eu/files/9814/6408/4022/CR-23-Sunscreens_Labelling.pdf |archive-date=2022-03-05 |access-date=2022-06-27}} This Commission recommendation specifies that the UVA protection factor should be measured using the PPD method as modified by the French health agency [[Agence nationale de sécurité du médicament et des produits de santé|AFSSAPS (now ANSM)]] "or an equivalent degree of protection obtained with any in vitro method".{{Cite web |date=2006-09-26 |title=Commission Recommendation of 22 September 2006 on the efficacy of sunscreen products and the claims made relating thereto (notified under document number C(2006) 4089) (Text with EEA relevance) |url=http://data.europa.eu/eli/reco/2006/647/oj/eng |language=en}} [111] => [112] => A set of final US FDA rules effective from summer 2012 defines the phrase "broad spectrum" as providing UVA protection proportional to the UVB protection, using a standardized testing method. [113] => [114] => ==== Star rating system ==== [115] => In the UK and Ireland, the [[Boots (chemist)|Boots]] star rating system is a proprietary ''[[in vitro]]'' method used to describe the ratio of UVA to UVB protection offered by sunscreen creams and sprays. Based on original work by Brian Diffey at [[Newcastle University]], the Boots Company in Nottingham, UK, developed a method that has been widely adopted by companies marketing these products in the UK. [116] => [117] => One-star products provide the lowest ratio of UVA protection, five-star products the highest. The method was revised in light of the Colipa UVA PF test and the revised EU recommendations regarding UVA PF. The method still uses a [[spectrophotometer]] to measure absorption of UVA versus UVB; the difference stems from a requirement to pre-irradiate samples (where this was not previously required) to give a better indication of UVA protection and photostability when the product is used. With the current methodology, the lowest rating is three stars, the highest being five stars. [118] => [119] => In August 2007, the FDA put out for consultation the proposal that a version of this protocol be used to inform users of American product of the protection that it gives against UVA; but this was not adopted, for fear it would be too confusing. [120] => [121] => ==== PA system ==== [122] => Asian brands, particularly Japanese ones, tend to use The Protection Grade of UVA (PA) system to measure the UVA protection that a sunscreen provides. The PA system is based on the PPD reaction and is now widely adopted on the labels of sunscreens. According to the Japan Cosmetic Industry Association, PA+ corresponds to a UVA protection factor between two and four, PA++ between four and eight, and PA+++ more than eight. This system was revised in 2013 to include PA++++ which corresponds to a PPD rating of sixteen or above. [123] => [124] => ==== Expiration Date ==== [125] => Some sunscreens include an [[expiration date]]—a date indicating when they may become less effective.{{cite news | vauthors = Gibson L |title=Is sunscreen from last year still good? When does sunscreen expire? |work=Mayo Clinic |url=https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/sunscreen-expire/faq-20057957 |url-status=live |access-date=June 22, 2018 |archive-url=https://web.archive.org/web/20201129195820/https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/sunscreen-expire/faq-20057957 |archive-date=November 29, 2020}} [126] => [127] => == Active ingredients == [128] => Sunscreen formulations contain UV absorbing compounds (the active ingredients) dissolved or dispersed in a mixture of other ingredients, such as water, oils, moisturizers, and antioxidants. The UV filters can be either: [129] => [130] => * [[organic chemistry|Organic compounds]] which absorb ultraviolet light.{{cite journal | vauthors = Cole C, Shyr T, Ou-Yang H | title = Metal oxide sunscreens protect skin by absorption, not by reflection or scattering | journal = Photodermatology, Photoimmunology & Photomedicine | volume = 32 | issue = 1 | pages = 5–10 | date = January 2016 | pmid = 26431814 | doi = 10.1111/phpp.12214 | s2cid = 20695063 | doi-access = free }} Some organic compounds ([[bisoctrizole]] and phenylene bis-diphenyltriazine) also partially reflect incident light. These are also referred to as "chemical" UV filters. [131] => * [[Inorganic chemistry|Inorganic compounds]] ([[zinc oxide]] and [[titanium dioxide]]) which reflect, scatter, and absorb UV light.{{cite web|title=Nanotechnology Information Center: Properties, Applications, Research, and Safety Guidelines|url=http://www.americanelements.com/nanotech.htm|publisher=[[American Elements]]|access-date=July 16, 2013|archive-date=October 6, 2014|archive-url=https://web.archive.org/web/20141006090949/http://www.americanelements.com/nanotech.htm|url-status=live}} These are also referred to as "mineral" filters. [132] => [133] => The organic compounds used as UV filter are often [[aromaticity|aromatic]] molecules [[conjugated system|conjugated]] with [[carbonyl]] groups. This general structure allows the molecule to absorb high-energy ultraviolet rays and release the energy as lower-energy rays, thereby preventing the skin-damaging ultraviolet rays from reaching the skin. So, upon exposure to UV light, most of the ingredients (with the notable exception of [[avobenzone]]) do not undergo significant chemical change, allowing these ingredients to retain the UV-absorbing potency without significant [[photodegradation]]. A chemical stabilizer is included in some sunscreens containing avobenzone to slow its breakdown. The stability of avobenzone can also be improved by [[bemotrizinol]],{{cite journal | vauthors = Chatelain E, Gabard B | title = Photostabilization of butyl methoxydibenzoylmethane (Avobenzone) and ethylhexyl methoxycinnamate by bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a new UV broadband filter | journal = Photochemistry and Photobiology | volume = 74 | issue = 3 | pages = 401–406 | date = September 2001 | pmid = 11594052 | doi = 10.1562/0031-8655(2001)074<0401:POBMAA>2.0.CO;2 | doi-broken-date = April 23, 2024 | s2cid = 29879472 }} [[octocrylene]]{{cite web|url=http://www.dsm.com/en_US/html/dnpus/pe_parsol_340.htm |publisher=DSM |title=Parsol 340 – Octocrylene |access-date=June 22, 2015 |url-status=unfit |archive-url=https://web.archive.org/web/20090803112741/http://www.dsm.com/en_US/html/dnpus/pe_parsol_340.htm |archive-date=August 3, 2009 }} and various other photostabilisers. Most organic compounds in sunscreens slowly degrade and become less effective over the course of several years even if stored properly, resulting in the [[shelf life|expiration dates]] calculated for the product.{{cite web |url=http://www.skincancer.org/skin-cancer-information/ask-the-experts/does-sunscreen-become-ineffective-with-age |title=Does sunscreen become ineffective with age? | vauthors = Burke KE |publisher=The Skin Cancer Foundation |access-date=July 31, 2014 |archive-date=August 8, 2014 |archive-url=https://web.archive.org/web/20140808044446/http://www.skincancer.org/skin-cancer-information/ask-the-experts/does-sunscreen-become-ineffective-with-age |url-status=live }} [134] => [135] => Sunscreening agents are used in some hair care products such as shampoos, conditioners and styling agents to protect against protein degradation and color loss. Currently, [[benzophenone-4]] and [[ethylhexyl methoxycinnamate]] are the two sunscreens most commonly used in hair products. The common sunscreens used on skin are rarely used for hair products due to their texture and weight effects. [136] => [137] => UV filters need usually to be approved by local agencies (such as the FDA in the United States) to be used in sunscreen formulations. As of 2023, 29 compounds are approved in the European Union and 17 in the USA.{{cite journal | vauthors = Pantelic MN, Wong N, Kwa M, Lim HW | title = Ultraviolet filters in the United States and European Union: A review of safety and implications for the future of US sunscreens | journal = Journal of the American Academy of Dermatology | volume = 88 | issue = 3 | pages = 632–646 | date = March 2023 | pmid = 36442641 | doi = 10.1016/j.jaad.2022.11.039 | s2cid = 254068728 }} No UV filters have been approved by the FDA for use in cosmetics since 1999. [138] => [139] => The following are the FDA allowable active ingredients in sunscreens: [140] => [141] => {{anchor|table}} [142] => {| class="wikitable" [143] => ! UV-filter [144] => ! Other names [145] => ! Maximum concentration [146] => ! Known permitting jurisdictions [147] => ! Results of safety testing [148] => ! UVA [149] => ! UVB [150] => |- [151] => | [[p-Aminobenzoic acid]] [152] => | PABA [153] => | 15% (USA), (EU: banned from sale to consumers from 8 October 2009) [154] => | USA [155] => | Protects against skin tumors in mice.{{cite journal | vauthors = Flindt-Hansen H, Thune P, Larsen TE | title = The inhibiting effect of PABA on photocarcinogenesis | journal = Archives of Dermatological Research | volume = 282 | issue = 1 | pages = 38–41 | year = 1990 | pmid = 2317082 | doi = 10.1007/BF00505643 | s2cid = 7535511 }}{{cite journal | vauthors = Flindt-Hansen H, Thune P, Eeg-Larsen T | title = The effect of short-term application of PABA on photocarcinogenesis | journal = Acta Dermato-Venereologica | volume = 70 | issue = 1 | pages = 72–75 | year = 1990 | pmid = 1967881 | doi = 10.2340/00015555707275 | s2cid = 44817557 | doi-access = free }}{{cite journal | vauthors = Osgood PJ, Moss SH, Davies DJ | title = The sensitization of near-ultraviolet radiation killing of mammalian cells by the sunscreen agent para-aminobenzoic acid | journal = The Journal of Investigative Dermatology | volume = 79 | issue = 6 | pages = 354–357 | date = December 1982 | pmid = 6982950 | doi = 10.1111/1523-1747.ep12529409 | doi-access = free }} Shown to increase DNA defects, and not [[Generally recognized as safe and effective|generally recognised as safe and effective]] according to the [[Food and Drug Administration|FDA]] [156] => | [157] => | X [158] => |- [159] => | [[Padimate O]] [160] => | OD-PABA, octyldimethyl-PABA, σ-PABA [161] => | 8% (USA, AUS) 10% (JP) [162] => (Not currently supported in EU and may be delisted) [163] => | EU, USA, AUS, JP [164] => | [165] => | [166] => | X [167] => |- [168] => | [[Phenylbenzimidazole sulfonic acid]] [169] => | Ensulizole, PBSA [170] => | 4% (USA, AUS) 8% (EU) 3% (JP) [171] => | EU, USA, AUS, JP [172] => | Genotoxic in bacteria{{cite journal | vauthors = Mosley CN, Wang L, Gilley S, Wang S, Yu H | title = Light-induced cytotoxicity and genotoxicity of a sunscreen agent, 2-phenylbenzimidazole in Salmonella typhimurium TA 102 and HaCaT keratinocytes | journal = International Journal of Environmental Research and Public Health | volume = 4 | issue = 2 | pages = 126–131 | date = June 2007 | pmid = 17617675 | pmc = 3728577 | doi = 10.3390/ijerph2007040006 | doi-access = free }} [173] => | [174] => | X [175] => |- [176] => | [[Cinoxate]] [177] => | 2-Ethoxyethyl p-methoxycinnamate [178] => | 3% (USA) 6% (AUS) [179] => | USA, AUS [180] => | [181] => | X [182] => | X [183] => |- [184] => | [[Dioxybenzone]] [185] => | Benzophenone-8 [186] => | 3% (USA) [187] => | USA, AUS [188] => | [189] => | X [190] => | X [191] => |- [192] => | [[Oxybenzone]] [193] => | Benzophenone-3 [194] => | 6% (USA), 2.2% (body) / 6% (face) EU,{{Cite web |title=Scientific Committee on Consumer Safety (SCCS) - OPINION on Benzophenone-3 |url=https://health.ec.europa.eu/system/files/2022-08/sccs_o_247.pdf |website=European Commission - SCCS}} 10% AUS, [195] => | EU, USA, AUS [196] => | Banned in Hawaii since 2018 - "harmful to coral reefs, fish, and other ocean life"{{Cite web | vauthors = Levine A |date=September 2019 |title=Sunscreen Use in Hawaii - AN ASSESSMENT OF BEACH-GOER USE OF SUNSCREEN PRIOR TO IMPLEMENTATION OF THE 2021 CHEMICAL BAN |url=https://www.kohalacenter.org/docs/reports/Sunscreen_Report_Sept2019.pdf |website=The Kohala Center |access-date=October 7, 2022 |archive-date=October 7, 2022 |archive-url=https://web.archive.org/web/20221007013029/https://www.kohalacenter.org/docs/reports/Sunscreen_Report_Sept2019.pdf |url-status=live }} [197] => | X [198] => | X [199] => |- [200] => | [[Homosalate]] [201] => | Homomethyl salicylate [202] => | 7.34% (EU) 15% (USA, AUS) [203] => | EU, USA, AUS [204] => | [205] => | [206] => | X [207] => |- [208] => | [[Menthyl anthranilate]] [209] => | Meradimate [210] => | 5% (USA) [211] => | USA, AUS [212] => | [213] => | X [214] => | [215] => |- [216] => | [[Octocrylene]] [217] => | Eusolex OCR, Parsol 340, 2-Cyano-3,3-diphenyl acrylic acid, 2-ethylhexylester [218] => | 10% (USA) [219] => | EU, USA, AUS [220] => | Increases [[reactive oxygen species]] (ROS){{cite journal | vauthors = Hanson KM, Gratton E, Bardeen CJ | title = Sunscreen enhancement of UV-induced reactive oxygen species in the skin | journal = Free Radical Biology & Medicine | volume = 41 | issue = 8 | pages = 1205–1212 | date = October 2006 | pmid = 17015167 | doi = 10.1016/j.freeradbiomed.2006.06.011 | s2cid = 13999532 | url = http://www.escholarship.org/uc/item/9f14s2dd | access-date = July 25, 2019 | url-status = live | archive-url = https://web.archive.org/web/20200806013940/https://www.escholarship.org/uc/item/9f14s2dd | archive-date = August 6, 2020 }} [221] => | X [222] => | X [223] => |- [224] => | [[Octinoxate]] [225] => | Octyl-methoxycinnamate, Ethylhexyl methoxycinnamate, 2-Ethylhexyl-paramethoxycinnamate [226] => | 7.5% (USA) 10% (EU, AUS) 20% (JP) [227] => | EU, USA, AUS, JP [228] => | Banned in [[Hawaii]] since 2021 - harmful to [[coral]]{{Cite news |url=https://www.washingtonpost.com/news/energy-environment/wp/2018/07/02/hawaii-is-about-to-ban-your-favorite-sunscreen-to-protect-its-coral-reefs/?noredirect=on |title=Hawaii is about to ban your favorite sunscreen to protect its coral reefs |newspaper=[[The Washington Post]] |access-date=July 2, 2018 |archive-date=June 8, 2019 |archive-url=https://web.archive.org/web/20190608221936/https://www.washingtonpost.com/news/energy-environment/wp/2018/07/02/hawaii-is-about-to-ban-your-favorite-sunscreen-to-protect-its-coral-reefs/?noredirect=on |url-status=live }} [229] => | [230] => | X [231] => |- [232] => | [[Octyl salicylate]] [233] => | Octisalate, 2-Ethylhexyl salicylate [234] => | 5% (EU, USA, AUS) 10% (JP) [235] => | EU, USA, AUS, JP [236] => | [237] => | [238] => | X [239] => |- [240] => | [[Sulisobenzone]] [241] => | 2-Hydroxy-4-Methoxybenzophenone-5-sulfonic acid, 3-Benzoyl-4-hydroxy-6-methoxybenzenesulfonic acid, Benzophenone-4 [242] => | 5% (EU) 10% (USA, AUS, JP) [243] => | EU, USA, AUS, JP [244] => | [245] => | X [246] => | X [247] => |- [248] => | [[Avobenzone]] [249] => | 1-(4-methoxyphenyl)-3-(4-tert-butyl
phenyl)propane-1,3-dione, Butyl methoxy dibenzoylmethane, [250] => | 3% (USA) 5% (EU, AUS) [251] => | EU, USA, AUS [252] => | [253] => | X [254] => | [255] => |- [256] => | [[Ecamsule]] [257] => | Terephthalylidene Dicamphor Sulfonic Acid [258] => | 10% [259] => | EU, AUS (US: approved in certain formulations up to 3% via New Drug Application (NDA) Route) [260] => | Protects against skin tumors in mice{{cite journal | vauthors = Lautenschlager S, Wulf HC, Pittelkow MR | title = Photoprotection | journal = Lancet | volume = 370 | issue = 9586 | pages = 528–537 | date = August 2007 | pmid = 17693182 | doi = 10.1016/S0140-6736(07)60638-2 | s2cid = 208794122 }}{{cite journal | vauthors = Benech-Kieffer F, Meuling WJ, Leclerc C, Roza L, Leclaire J, Nohynek G | title = Percutaneous absorption of Mexoryl SX in human volunteers: comparison with in vitro data | journal = Skin Pharmacology and Applied Skin Physiology | volume = 16 | issue = 6 | pages = 343–355 | date = Nov–Dec 2003 | pmid = 14528058 | doi = 10.1159/000072929 | s2cid = 32449642 }}{{cite journal | vauthors = Fourtanier A | title = Mexoryl SX protects against solar-simulated UVR-induced photocarcinogenesis in mice | journal = Photochemistry and Photobiology | volume = 64 | issue = 4 | pages = 688–693 | date = October 1996 | pmid = 8863475 | doi = 10.1111/j.1751-1097.1996.tb03125.x | s2cid = 96058554 }} [261] => | X [262] => | [263] => |- [264] => | [[Titanium dioxide]] [265] => | CI77891, TiO₂ [266] => | 25% (US) No limit (JP) [267] => | EU, USA, AUS, JP [268] => | [[Generally recognized as safe and effective]] by the [[Food and Drug Administration|FDA]]{{Cite journal | author = Center for Drug Evaluation and Research |date=2022-12-16 |title=Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen |url=https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fda-posts-deemed-final-order-and-proposed-order-over-counter-sunscreen |journal=FDA |language=en}} [269] => | [270] => | X [271] => |- [272] => | [[Zinc oxide]] [273] => | CI77947, ZnO [274] => | 25% (US) No limit (AUS, JP) [275] => | EU, USA, AUS, JP [276] => | [[Generally recognized as safe and effective]] by the [[Food and Drug Administration|FDA]]. Protects against skin tumors in mice [277] => | X [278] => | X [279] => |} [280] => Zinc oxide was approved as a UV filter by the EU in 2016.{{Cite web|url=http://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32016R0621&from=EN|title=Amending Annex VI to Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products|date=2016-04-21|website=eur-lex.europa.eu|access-date=2017-03-22|archive-date=August 11, 2020|archive-url=https://web.archive.org/web/20200811184457/https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32016R0621&from=EN|url-status=live}} [281] => [282] => Other ingredients approved within the EU{{cite journal |url=http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009R1223&qid=1406148728060&from=EN |title=Regulation No. 1223/2009 on cosmetic products |journal=Official Journal of the European Union |date=December 22, 2009 |access-date=May 26, 2015 |archive-date=November 7, 2018 |archive-url=https://web.archive.org/web/20181107015619/https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009R1223&qid=1406148728060&from=EN |url-status=live }} and other parts of the world,{{cite web |url=http://www.tga.gov.au/publication/australian-regulatory-guidelines-sunscreens-args |title=Australian Regulatory Guidelines for Sunscreens |author=Australian Government: [[Therapeutic Goods Administration]] |date=November 2012 |access-date=June 21, 2015 |archive-date=September 28, 2020 |archive-url=https://web.archive.org/web/20200928033417/https://www.tga.gov.au/publication/australian-regulatory-guidelines-sunscreens-args |url-status=dead }} that have not been included in the current FDA Monograph: [283] => [284] => {| class="wikitable" [285] => ! UV-filter [286] => ! Other names [287] => ! Maximum concentration [288] => ! Permitted in [289] => !Results of safety testing [290] => !UVA [291] => !UVB [292] => |- [293] => | [[4-Methylbenzylidene camphor]] [294] => | Enzacamene, MBC [295] => | 4%* [296] => | EU, AUS [297] => | [298] => | [299] => | [300] => |- [301] => | [[Bisoctrizole]] [302] => | Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, MBBT [303] => | 10%* [304] => | EU, AUS, JP [305] => | [306] => | [307] => | [308] => |- [309] => | [[Bemotrizinol]] [310] => | Bis-ethylhexyloxyphenol methoxyphenol triazine, BEMT, anisotriazine [311] => | 10% (EU, AUS) 3% (JP)* [312] => | EU, AUS, JP [313] => | [314] => | [315] => | [316] => |- [317] => | Tris-biphenyl triazine [318] => | [319] => | 10% [320] => | EU, AUS [321] => | [322] => | [323] => | [324] => |- [325] => | [[Trolamine salicylate]] [326] => | Triethanolamine salicylate [327] => | 12% [328] => | AUS [329] => |Not [[Generally recognized as safe and effective|generally recognised as safe and effective]] according to the [[Food and Drug Administration|FDA]]. Removed from the market in the USA.{{Cite journal |last=Research |first=Center for Drug Evaluation and |date=2022-12-16 |title=Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen |url=https://www.fda.gov/drugs/understanding-over-counter-medicines/questions-and-answers-fda-posts-deemed-final-order-and-proposed-order-over-counter-sunscreen |journal=FDA |language=en}} [330] => | [331] => |X [332] => |- [333] => | [[Drometrizole trisiloxane]] [334] => | [335] => | 15% [336] => | EU, AUS [337] => | [338] => | [339] => | [340] => |- [341] => | [[Benzophenone-n|Benzophenone-9]] [342] => | CAS 3121-60-6, Sodium Dihydroxy Dimethoxy Disulfobenzophenone {{cite web |url=http://www.basf-korea.co.kr/02_products/04_finechemicals/document/cosmetic/tech/uvabsorber/down.asp?file=uvinulgrades.pdf |title=Uvinul Grades |access-date=2009-09-25 |archive-date=July 31, 2009 |archive-url=https://web.archive.org/web/20090731133525/http://www.basf-korea.co.kr/02_products/04_finechemicals/document/cosmetic/tech/uvabsorber/down.asp?file=uvinulgrades.pdf |url-status=live }} [343] => | 10% [344] => | JP [345] => | [346] => | [347] => | [348] => |- [349] => | [[Ethylhexyl triazone]] [350] => | octyl triazone, EHT [351] => | 5% (EU, AUS) 3% (JP)* [352] => | EU, AUS [353] => | [354] => | [355] => | [356] => |- [357] => | [[Diethylamino hydroxybenzoyl hexyl benzoate]] [358] => | [359] => | 10% [360] => | EU, JP, AUS [361] => | [362] => | [363] => | [364] => |- [365] => | [[Iscotrizinol]] [366] => | diethylhexyl butamido triazone, DBT [367] => | 10% (EU) 5% (JP)* [368] => | EU, JP [369] => | [370] => | [371] => | [372] => |- [373] => | [[Polysilicone-15]] [374] => | Dimethico-diethylbenzalmalonate [375] => | 10% [376] => | EU, AUS, JP [377] => | [378] => | [379] => | [380] => |- [381] => | [[Amiloxate]] [382] => | Isopentyl-4-methoxycinnamate, Isoamyl p-Methoxycinnamate, IMC [383] => | 10%* [384] => | EU, AUS [385] => | [386] => | [387] => | [388] => |} [389] => [390] => * Time and Extent Application (TEA), Proposed Rule on FDA approval originally expected 2009, now expected 2015.{{Update inline|date=October 2023|reason=Still no news from FDA about approval in 2023}} [391] => [392] => Many of the ingredients awaiting approval by the FDA are relatively new, and developed to absorb UVA.{{cite journal | author = Kapes B |url=http://www.modernmedicine.com/modernmedicine/article/articleDetail.jsp?id=169626 |title=Docs rally for better sun protection — Advances still unavailable in United States |journal=Dermatology Times |volume=26 |issue=7 |page=100 |date=July 2005 |access-date=July 23, 2014 |archive-date=April 7, 2012 |archive-url=https://web.archive.org/web/20120407114700/http://www.modernmedicine.com/modernmedicine/article/articleDetail.jsp?id=169626 |url-status=live }} The 2014 [[Sunscreen Innovation Act]] was passed to accelerate the FDA approval process.{{cite web |url=https://www.congress.gov/bill/113th-congress/senate-bill/2141/all-actions |title=Sunscreen Innovation Act |date=November 26, 2014 |publisher=United States Congress |access-date=January 5, 2015 |archive-date=August 24, 2020 |archive-url=https://web.archive.org/web/20200824070454/https://www.congress.gov/bill/113th-congress/senate-bill/2141/all-actions |url-status=live }}{{cite magazine | vauthors = Sifferlin A |title=We're One Step Closer to Better Sunscreen |url=http://time.com/2992200/were-one-step-closer-to-better-sunscreen/ |magazine=Time |date=July 16, 2014 |access-date=August 1, 2014}} [393] => [394] => == Inactive ingredients == [395] => It is known that SPF is affected by not only the choice of active ingredients and the percentage of active ingredients but also the formulation of the vehicle/base. Final SPF is also impacted by the distribution of active ingredients in the sunscreen, how evenly the sunscreen applies on the skin, how well it dries down on the skin and the pH value of the product among other factors. Changing any inactive ingredient may potentially alter a sunscreen's SPF.{{Cite web | author = Australian Government Department of Health Therapeutic Goods Administration |date=2019-08-30|title=Australian Regulatory Guidelines for Sunscreens (ARGS)|url=https://www.tga.gov.au/resource/australian-regulatory-guidelines-sunscreens-args|access-date=2021-07-26|website=Therapeutic Goods Administration (TGA)|language=en|archive-date=July 27, 2021|archive-url=https://web.archive.org/web/20210727000206/https://www.tga.gov.au/resource/australian-regulatory-guidelines-sunscreens-args|url-status=live}}{{Cite web | vauthors = Gao T, Tien JM, Choi YH | publisher = Croda Inc , North American Technical Center |title=Sunscreen Formulas With Multilayer Lamella Structure|url=https://www.cosmeticsandtoiletries.com/formulating/function/viscositymod/2696511.html|access-date=2021-08-13| work = Cosmetics & Toiletries|date=June 24, 2009|archive-date=August 13, 2021|archive-url=https://web.archive.org/web/20210813154806/https://www.cosmeticsandtoiletries.com/formulating/function/viscositymod/2696511.html|url-status=live}} [396] => [397] => When combined with UV filters, added [[antioxidant]]s can work synergistically to affect the overall SPF value positively. Furthermore, adding antioxidants to sunscreen can amplify its ability to reduce markers of extrinsic photoaging, grant better protection from [[Liver spot|UV induced pigment formation]], mitigate skin [[lipid peroxidation]], improve the photostability of the active ingredients, neutralize reactive oxygen species formed by irradiated photocatalysts ''(e.g., uncoated TiO₂)'' and aid in DNA repair post-UVB damage, thus enhancing the efficiency and safety of sunscreens.{{cite journal | vauthors = Wu Y, Matsui MS, Chen JZ, Jin X, Shu CM, Jin GY, Dong GH, Wang YK, Gao XH, Chen HD, Li YH | display-authors = 6 | title = Antioxidants add protection to a broad-spectrum sunscreen | journal = Clinical and Experimental Dermatology | volume = 36 | issue = 2 | pages = 178–187 | date = March 2011 | pmid = 20804506 | doi = 10.1111/j.1365-2230.2010.03916.x | s2cid = 25145335 }}{{cite journal | vauthors = Dahabra L, Broadberry G, Le Gresley A, Najlah M, Khoder M | title = Sunscreens Containing Cyclodextrin Inclusion Complexes for Enhanced Efficiency: A Strategy for Skin Cancer Prevention | journal = Molecules | volume = 26 | issue = 6 | pages = 1698 | date = March 2021 | pmid = 33803643 | pmc = 8003006 | doi = 10.3390/molecules26061698 | doi-access = free }}{{cite journal | vauthors = Darr D, Dunston S, Faust H, Pinnell S | title = Effectiveness of antioxidants (vitamin C and E) with and without sunscreens as topical photoprotectants | journal = Acta Dermato-Venereologica | volume = 76 | issue = 4 | pages = 264–268 | date = July 1996 | pmid = 8869680 | doi = 10.2340/0001555576264268 | s2cid = 45260180 | doi-access = free }}{{cite journal | vauthors = Dorjay K, Arif T, Adil M | title = Silymarin: An interesting modality in dermatological therapeutics | journal = Indian Journal of Dermatology, Venereology and Leprology | volume = 84 | issue = 2 | pages = 238–243 | date = 2018 | pmid = 29350205 | doi = 10.4103/ijdvl.IJDVL_746_16 | url = https://ijdvl.com/?view-pdf=1&embedded=true&article=6d28812c6c2103e3ad1d17bc15c089c1haeLWQ%3D%3D | url-status = live | s2cid = 46884296 | doi-access = free | archive-url = https://web.archive.org/web/20220321191152/https://ijdvl.com/?view-pdf=1&embedded=true&article=6d28812c6c2103e3ad1d17bc15c089c1haeLWQ%3D%3D | archive-date = March 21, 2022 }} Compared with sunscreen alone, it has been shown that the addition of antioxidants has the potential to suppress [[Reactive oxygen species|ROS]] formation by an additional 1.7-fold for SPF 4 sunscreens and 2.4-fold for SPF 15-to-SPF 50 sunscreens, but the efficacy depends on how well the sunscreen in question has been formulated. Sometimes [[osmolyte]]s are also incorporated into commercially available sunscreens in addition to antioxidants since they also aid in protecting the skin from the detrimental effects of UVR.{{cite journal | vauthors = Rai R, Shanmuga SC, Srinivas C | title = Update on photoprotection | journal = Indian Journal of Dermatology | volume = 57 | issue = 5 | pages = 335–342 | date = September 2012 | pmid = 23112351 | pmc = 3482794 | doi = 10.4103/0019-5154.100472 | doi-access = free }} Examples include the osmolyte taurine, which has demonstrated the ability to protects against UVB-radiation induced immunosuppression{{cite journal | vauthors = Rockel N, Esser C, Grether-Beck S, Warskulat U, Flögel U, Schwarz A, Schwarz T, Yarosh D, Häussinger D, Krutmann J | display-authors = 6 | title = The osmolyte taurine protects against ultraviolet B radiation-induced immunosuppression | journal = Journal of Immunology | volume = 179 | issue = 6 | pages = 3604–3612 | date = September 2007 | pmid = 17785795 | doi = 10.4049/jimmunol.179.6.3604 | s2cid = 26059060 | doi-access = free }} and the osmolyte ectoine, which aids in counteracting cellular accelerated aging & UVA-radiation induced premature photoaging.{{cite journal | vauthors = Buenger J, Driller H | title = Ectoin: an effective natural substance to prevent UVA-induced premature photoaging | journal = Skin Pharmacology and Physiology | volume = 17 | issue = 5 | pages = 232–237 | date = September 2004 | pmid = 15452409 | doi = 10.1159/000080216 | s2cid = 44762987 }} [398] => [399] => Other inactive ingredients can also assist in photostabilizing unstable UV filters. [[Cyclodextrin]]s have demonstrated the ability to reduce photodecomposition, protect antioxidants and limit skin penetration past the [[Stratum corneum|uppermost skin layers]], allowing them to longer maintain the protection factor of sunscreens with UV filters that are highly unstable and/or easily permeate to the lower layers of the skin.{{cite journal | vauthors = Yang J, Wiley CJ, Godwin DA, Felton LA | title = Influence of hydroxypropyl-beta-cyclodextrin on transdermal penetration and photostability of avobenzone | journal = European Journal of Pharmaceutics and Biopharmaceutics | volume = 69 | issue = 2 | pages = 605–612 | date = June 2008 | pmid = 18226883 | doi = 10.1016/j.ejpb.2007.12.015 }}{{cite journal | vauthors = Shokri J, Hasanzadeh D, Ghanbarzadeh S, Dizadji-Ilkhchi M, Adibkia K | title = The effect of Beta-cyclodextrin on percutaneous absorption of commonly used Eusolex® sunscreens | journal = Drug Research | volume = 63 | issue = 11 | pages = 591–596 | date = November 2013 | pmid = 23842944 | doi = 10.1055/s-0033-1349089 | s2cid = 206350641 }} Similarly, [[Film-forming agent|film-forming polymers]] like polyester-8 and polycryleneS1 have the ability to protect the efficacy of older petrochemical UV filters by preventing them from destabilizing due to extended light exposure. These kinds of ingredients also increase the water resistance of sunscreen formulations.{{Cite web| vauthors = Schaefer K |title=Polycrylene for Photostabilization and Water Resistance|url=https://www.cosmeticsandtoiletries.com/formulating/category/suncare/161093645.html|access-date=2021-07-27|website=Cosmetics & Toiletries|date=July 3, 2012|archive-date=July 27, 2021|archive-url=https://web.archive.org/web/20210727221939/https://www.cosmeticsandtoiletries.com/formulating/category/suncare/161093645.html|url-status=live}}{{Cite web | title=Hallstar develops photostabilizer for sun care products|url=https://www.cosmeticsdesign.com/Article/2012/07/02/Hallstar-develops-photostabilizer-for-sun-care-products|access-date=2021-07-27|website=cosmeticsdesign.com|language=en-GB}} [400] => [401] => [[File:Commercial Sunscreens with UV and Non-UV solar radiation protection.jpeg|thumb|upright=1.35|right|“Advanced Protection” sunscreens from around the world, all utilizing different additives to protect the wearer beyond the ultraviolet spectral range]] [402] => [403] => [404] => In the 2010s & 2020s, there has been increasing interest in sunscreens that protect the wearer from the sun's [[high-energy visible light]] & [[infrared|iinfrared light]] as well as ultraviolet light. This is due to newer research revealing [[Spectral color#Table of spectral or near-spectral colors|blue & violet visible light]] and certain wavelengths of infrared light ''(e.g., [[Infrared#Commonly used sub-division scheme|NIR, IR-A]])'' work synergistically with UV light in contributing to oxidative stress, free radical generation, dermal cellular damage, suppressed skin healing, decreased immunity, erythema, inflammation, dryness, and several aesthetic concerns, such as: wrinkle formation, loss of skin elasticity and dyspigmentation.{{cite journal | vauthors = Lademann J, Meinke MC, Schanzer S, Albrecht S, Zastrow L | title = [New aspects in the development of sunscreening agents] | language = de | journal = Der Hautarzt; Zeitschrift Fur Dermatologie, Venerologie, und Verwandte Gebiete | volume = 68 | issue = 5 | pages = 349–353 | date = May 2017 | pmid = 28280909 | doi = 10.1007/s00105-017-3965-9 | s2cid = 195671296 | trans-title = New aspects in the development of sunscreening agents }}{{cite journal | vauthors = Krutmann J, Berneburg M | title = [Sun-damaged skin (photoaging): what is new?] | language = de | journal = Der Hautarzt; Zeitschrift Fur Dermatologie, Venerologie, und Verwandte Gebiete | volume = 72 | issue = 1 | pages = 2–5 | date = January 2021 | pmid = 33346860 | doi = 10.1007/s00105-020-04747-4 | s2cid = 229342851 | trans-title = Sun-damaged skin (photoaging): what is new? }}{{cite journal | vauthors = Souza C, Maia Campos P, Schanzer S, Albrecht S, Lohan SB, Lademann J, Darvin ME, Meinke MC | display-authors = 6 | title = Radical-Scavenging Activity of a Sunscreen Enriched by Antioxidants Providing Protection in the Whole Solar Spectral Range | journal = Skin Pharmacology and Physiology | volume = 30 | issue = 2 | pages = 81–89 | date = 2017 | pmid = 28319939 | doi = 10.1159/000458158 | s2cid = 6252032 | doi-access = free }}{{cite journal | vauthors = Michalski B, Olasz E | title = What You Didn't Know About the Sun: Infrared Radiation and Its Role in Photoaging | journal = Plastic Surgical Nursing | volume = 40 | issue = 3 | pages = 166–168 | date = July 2020 | pmid = 32852443 | doi = 10.1097/PSN.0000000000000334 | s2cid = 221347292 }}{{Cite web | vauthors = Piras E |date=2 May 2018 |title=Synergy of mica and inorganic UV filters maximizes Blue Light Protection as first defense line |url=https://ifscc.org/wp-content/uploads/2019/05/Emanuele-Piras-_Synergy-of-mica-and-inorganic-UV-filters-for-Blue-Light-Protection.pdf |website=[[International Federation of Societies of Cosmetic Chemists]] |publisher=Merck |location=Germany |access-date=July 27, 2021 |archive-date=July 27, 2021 |archive-url=https://web.archive.org/web/20210727221939/https://ifscc.org/wp-content/uploads/2019/05/Emanuele-Piras-_Synergy-of-mica-and-inorganic-UV-filters-for-Blue-Light-Protection.pdf |url-status=live }}{{cite journal | vauthors = Zastrow L, Groth N, Klein F, Kockott D, Lademann J, Ferrero L | title = [UV, visible and infrared light. Which wavelengths produce oxidative stress in human skin?] | language = de | journal = Der Hautarzt; Zeitschrift Fur Dermatologie, Venerologie, und Verwandte Gebiete | volume = 60 | issue = 4 | pages = 310–317 | date = April 2009 | pmid = 19319493 | doi = 10.1007/s00105-008-1628-6 | s2cid = 115358035 | trans-title = UV, visible and infrared light. Which wavelengths produce oxidative stress in human skin? }}{{Cite web |date=June 2017 |title=Advanced Sun protection with Titanium Dioxides and Functional Fillers |website=Conselho Regional de Química - IV Região |publisher=Merck |url=https://www.crq4.org.br/sms/files/file/eventos/seminario_prot_inoutdoor_2018/palestra_advanced_alexander_kielbassa.pdf |url-status=dead |access-date=12 March 2022 |archive-url=https://web.archive.org/web/20210728183624/https://www.crq4.org.br/sms/files/file/eventos/seminario_prot_inoutdoor_2018/palestra_advanced_alexander_kielbassa.pdf |archive-date=28 July 2021}} Increasingly, a number of commercial sunscreens are being produced that have manufacturer claims regarding skin protection from blue light, infrared light and even air pollution. However, as of 2021 there are no regulatory guidelines or mandatory testing protocols that govern these claims.{{cite journal | vauthors = Lim HW, Arellano-Mendoza MI, Stengel F | title = Current challenges in photoprotection | journal = Journal of the American Academy of Dermatology | volume = 76 | issue = 3S1 | pages = S91–S99 | date = March 2017 | pmid = 28038886 | doi = 10.1016/j.jaad.2016.09.040 | doi-access = free }} Historically, the American FDA has only recognized protection from sunburn ''(via UVB protection)'' and protection from skin cancer ''(via SPF 15+ with some UVA protection)'' as drug/medicinal sunscreen claims, so they do not have regulatory authority over sunscreen claims regarding protecting the skin from damage from these other environmental stressors.{{cite web |title=Labeling and Effectiveness Testing: Sunscreen Drug Products for Over-The-Counter Human Use — Small Entity Compliance Guide |url=https://www.fda.gov/regulatory-information/search-fda-guidance-documents/labeling-and-effectiveness-testing-sunscreen-drug-products-over-counter-human-use-small-entity |website=U.S. Food and Drug Administration |publisher=Center for Drug Evaluation and Research |access-date=31 July 2021 |language=en |date=22 March 2018 |archive-date=July 31, 2021 |archive-url=https://web.archive.org/web/20210731192208/https://www.fda.gov/regulatory-information/search-fda-guidance-documents/labeling-and-effectiveness-testing-sunscreen-drug-products-over-counter-human-use-small-entity |url-status=live }} Since sunscreen claims not related to protection from ultraviolet light are treated as [[cosmeceutical]] claims rather than drug/medicinal claims, the innovative technologies and additive ingredients used to allegedly reduce the damage from these other environmental stressors may vary widely from brand to brand. [405] => [406] => Some studies show that mineral sunscreens primarily made with substantially large particles ''(i.e., neither nano nor micronized)'' may help protect from visible and infrared light to some degree,{{cite journal | vauthors = Kim SJ, Bae J, Lee SE, Lee JB, Park CH, Lim DH, Park MS, Ha J | display-authors = 6 | title = A novel in vivo test method for evaluating the infrared radiation protection provided by sunscreen products | journal = Skin Research and Technology | volume = 25 | issue = 6 | pages = 890–895 | date = November 2019 | pmid = 31338921 | doi = 10.1111/srt.12754 | s2cid = 198194413 }} but these sunscreens are often unacceptable to consumers due to leaving an obligatory opaque white cast on the skin. Further research has shown that sunscreens with added [[Iron oxide|iron oxide pigments]] and/or pigmentary titanium dioxide can provide the wearer with a substantial amount of HEVL protection.{{cite journal | vauthors = Dumbuya H, Grimes PE, Lynch S, Ji K, Brahmachary M, Zheng Q, Bouez C, Wangari-Talbot J | display-authors = 6 | title = Impact of Iron-Oxide Containing Formulations Against Visible Light-Induced Skin Pigmentation in Skin of Color Individuals | journal = Journal of Drugs in Dermatology | volume = 19 | issue = 7 | pages = 712–717 | date = July 2020 | pmid = 32726103 | doi = 10.36849/JDD.2020.5032 | s2cid = 220877124 | doi-access = free }}{{cite journal | vauthors = Bernstein EF, Sarkas HW, Boland P | title = Iron oxides in novel skin care formulations attenuate blue light for enhanced protection against skin damage | journal = Journal of Cosmetic Dermatology | volume = 20 | issue = 2 | pages = 532–537 | date = February 2021 | pmid = 33210401 | pmc = 7894303 | doi = 10.1111/jocd.13803 }}{{cite journal | vauthors = Lyons AB, Trullas C, Kohli I, Hamzavi IH, Lim HW | title = Photoprotection beyond ultraviolet radiation: A review of tinted sunscreens | journal = Journal of the American Academy of Dermatology | volume = 84 | issue = 5 | pages = 1393–1397 | date = May 2021 | pmid = 32335182 | doi = 10.1016/j.jaad.2020.04.079 | s2cid = 216556227 }} Cosmetic chemists have found that other [[cosmetic-grade]] pigments can be functional filler ingredients. [[Mica]] was discovered to have significant synergistic effects with UVR filters when formulated in sunscreens, in that it can notably increase the formula's ability to protect the wearer from HEVL. [407] => [408] => There is a growing amount of research demonstrating that adding various vitamer antioxidants ''(eg; [[retinol]], [[Gamma-Tocopherol|alpha tocopherol, gamma tocopherol]], [[tocopheryl acetate]], [[Vitamin C|ascorbic acid]], [[Vitamer#List of vitamins with some of their active forms|ascorbyl tetraisopalmitate, ascorbyl palmitate, sodium ascorbyl phosphate]], [[Coenzyme Q10|ubiquinone]])'' and/or a mixture of certain botanical antioxidants ''(eg; [[Epigallocatechin gallate|epigallocatechin-3-gallate]], [[Beta-Carotene|b-carotene]], [[vitis vinifera]], [[Silybum marianum|silymarin]], [[Spirulina (dietary supplement)|spirulina extract]], [[Chamomile|chamomile extract]] and possibly others)'' to sunscreens efficaciously aids in reducing damage from the free radicals produced by exposure to solar ultraviolet radiation, visible light, near infrared radiation and infrared-a radiation.{{cite journal | vauthors = Grether-Beck S, Marini A, Jaenicke T, Krutmann J | title = Effective photoprotection of human skin against infrared A radiation by topically applied antioxidants: results from a vehicle controlled, double-blind, randomized study | journal = Photochemistry and Photobiology | volume = 91 | issue = 1 | pages = 248–250 | date = January 2015 | pmid = 25349107 | doi = 10.1111/php.12375 | s2cid = 206270691 }}{{cite journal | vauthors = Carlotti ME, Ugazio E, Gastaldi L, Sapino S, Vione D, Fenoglio I, Fubini B | title = Specific effects of single antioxidants in the lipid peroxidation caused by nano-titania used in sunscreen lotions | journal = Journal of Photochemistry and Photobiology. B, Biology | volume = 96 | issue = 2 | pages = 130–135 | date = August 2009 | pmid = 19527937 | doi = 10.1016/j.jphotobiol.2009.05.001 }} Since sunscreen's active ingredients work preventatively by creating a shielding film on the skin that absorbs, scatters, and reflects light before it can reach the skin, UV filters have been deemed an ideal “first line of defense” against sun damage when exposure can't be avoided. Antioxidants have been deemed a good “second line of defense” since they work responsively by decreasing the overall burden of free radicals that do reach the skin. The degree of the free radical protection from the entire solar spectral range that a sunscreen can offer has been termed the "radical protection factor" (RPF) by some researchers. [409] => [410] => == Application == [411] => SPF 30 or above must be used to effectively prevent UV rays from damaging skin cells. This is the amount that is recommended to prevent against skin cancer. Sunscreen must also be applied thoroughly and re-applied during the day, especially after being in the water. Special attention should be paid to areas like the ears and nose, which are common spots of skin cancer. Dermatologists may be able to advise about what sunscreen is best to use for specific skin types.{{cite web |title=Skin Cancer Foundation |url=https://www.skincancer.org/skin-cancer-prevention/ |access-date=December 12, 2021 |archive-date=December 12, 2021 |archive-url=https://web.archive.org/web/20211212032437/https://www.skincancer.org/skin-cancer-prevention/ |url-status=live }} [412] => [413] => The dose used in FDA sunscreen testing is 2 mg/cm2 of exposed skin.{{cite web | url=https://www.fda.gov/ohrms/dockets/dailys/00/Sep00/090600/c000573_10_Attachment_F.pdf | title=Re: Tentative Final Monograph for OTC Sunscreen | vauthors = Kavanaugh EW | publisher=Cosmetic, Toiletry, and Fragrance Association | date=1998-09-11 | access-date=2009-09-25 | archive-date=February 21, 2017 | archive-url=https://web.archive.org/web/20170221045451/https://www.fda.gov/ohrms/dockets/dailys/00/Sep00/090600/c000573_10_attachment_F.pdf | url-status=live }} If one assumes an "average" adult build of height 5 ft 4 in (163 cm) and weight 150 lb (68 kg) with a 32-inch (82-cm) waist, that adult wearing a bathing suit covering the groin area should apply approximately 30 g (or 30 ml, approximately 1 oz) evenly to the uncovered body area. This can be more easily thought of as a "golf ball" size amount of product per body, or at least six teaspoonfuls. Larger or smaller individuals should scale these quantities accordingly.{{cite web |url=http://www.thefactsabout.co.uk/how-and-why-we-use-sunscreen/content/239 |title=How and why we use sunscreen |publisher=Cosmetic, Toiletry & Perfumery Association |access-date=May 11, 2016 |archive-date=September 18, 2016 |archive-url=https://web.archive.org/web/20160918071256/http://www.thefactsabout.co.uk/how-and-why-we-use-sunscreen/content/239 |url-status=dead }} Considering only the face, this translates to about 1/4 to 1/3 of a teaspoon for the average adult face. [414] => [415] => Some studies have shown that people commonly apply only 1/4 to 1/2 of the amount recommended for achieving the rated sun protection factor (SPF), and in consequence the effective SPF should be downgraded to a 4th root or a square root of the advertised value, respectively.{{cite journal | vauthors = Faurschou A, Wulf HC | title = The relation between sun protection factor and amount of suncreen applied in vivo | journal = The British Journal of Dermatology | volume = 156 | issue = 4 | pages = 716–719 | date = April 2007 | pmid = 17493070 | doi = 10.1111/j.1365-2133.2006.07684.x | s2cid = 22599824 }} A later study found a significant exponential relation between SPF and the amount of sunscreen applied, and the results are closer to linearity than expected by theory.{{cite journal | vauthors = Schalka S, dos Reis VM, Cucé LC | title = The influence of the amount of sunscreen applied and its sun protection factor (SPF): evaluation of two sunscreens including the same ingredients at different concentrations | journal = Photodermatology, Photoimmunology & Photomedicine | volume = 25 | issue = 4 | pages = 175–180 | date = August 2009 | pmid = 19614894 | doi = 10.1111/j.1600-0781.2009.00408.x | s2cid = 38250220 }} [416] => [417] => Claims that substances in pill form can act as sunscreen are false and disallowed in the United States.{{cite web |title=Press Announcements - Statement from FDA Commissioner Scott Gottlieb, M.D., on new FDA actions to keep consumers safe from the harmful effects of sun exposure, and ensure the long-term safety and benefits of sunscreens |url=https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm608499.htm |website=www.fda.gov |access-date=23 August 2018 |language=en |archive-date=November 14, 2020 |archive-url=https://web.archive.org/web/20201114162137/https://www.fda.gov/news-events/press-announcements/statement-fda-commissioner-scott-gottlieb-md-new-fda-actions-keep-consumers-safe-harmful-effects-sun |url-status=live }} [418] => [419] => == Regulation == [420] => {{Expand section|date=January 2018}} [421] => ; Palau [422] => On 1 January 2020, [[Palau]] banned the manufacturing and selling of sun cream products containing any of the following ingredients: [[benzophenone-3]], [[octyl methoxycinnamate]], [[octocrylene]], [[Enzacamene|4-methyl-benzylidene camphor]], [[triclosan]], [[methylparaben]], [[ethylparaben]], [[butylparaben]], [[benzyl paraben]], and [[phenoxyethanol]].{{cite news|url=https://www.allcleartravel.co.uk/blog/palau-bans-reef-toxic-sunscreens/|title=Palau Bans 'Reef Toxic' Sunscreens|date=23 January 2020|access-date=August 9, 2023 }} The decision was taken to protect the local coral reef and sea life.{{cite news|url=https://www.bbc.com/news/world-asia-50963080|title=Palau is first country to ban 'reef toxic' sun cream|work=[[BBC News]]|date=1 January 2020|access-date=January 1, 2020|archive-date=November 27, 2020|archive-url=https://web.archive.org/web/20201127145518/https://www.bbc.com/news/world-asia-50963080|url-status=live}} Those compounds are known or suspected to be harmful to coral or other sea life. [423] => [424] => ; United States [425] => Sunscreen labeling standards have been evolving in the United States since the FDA first adopted the SPF calculation in 1978.{{cite journal |author=Department of Health and Human Services: Food and Drug Administration |date=August 25, 1978 |title=Sunscreen Drug Products for Over-the-Counter Human Use |url=https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/ucm090127.pdf |journal=[[Federal Register]] |volume=43 |issue=166 |pages=38206–38269 |access-date=July 30, 2014 |archive-date=February 22, 2017 |archive-url=https://web.archive.org/web/20170222153034/https://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/Over-the-CounterOTCDrugs/StatusofOTCRulemakings/ucm090127.pdf |url-status=live }} The FDA issued a comprehensive set of rules in June 2011, taking effect in 2012–2013, designed to help consumers identify and select suitable sunscreen products offering protection from sunburn, early skin aging, and skin cancer.{{cite web |date=2011-06-23 |title=Questions and Answers: FDA announces new requirements for over-the-counter (OTC) sunscreen products marketed in the U.S. |url=https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm |access-date=2012-04-10 |website=[[Food and Drug Administration]] |archive-date=April 23, 2019 |archive-url=https://web.archive.org/web/20190423132658/https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm |url-status=live }}{{cite journal |author=Department of Health and Human Services: Food and Drug Administration |date=June 17, 2011 |title=Sunscreen Drug Products for Over-the-Counter Human Use; Final Rules and Proposed Rules |url=http://www.gpo.gov/fdsys/pkg/FR-2011-06-17/pdf/2011-14766.pdf |journal=Federal Register |volume=76 |issue=117 |pages=35620–35665 |access-date=August 19, 2014 |archive-date=October 19, 2020 |archive-url=https://web.archive.org/web/20201019123401/https://www.govinfo.gov/content/pkg/FR-2011-06-17/pdf/2011-14766.pdf |url-status=live }}{{cite journal |author=Department of Health and Human Services: Food and Drug Administration |date=May 11, 2012 |title=Sunscreen Drug Products for Over-the-Counter Human Use; Delay of Compliance Dates |url=http://www.gpo.gov/fdsys/pkg/FR-2012-05-11/pdf/2012-11390.pdf |journal=Federal Register |volume=77 |issue=92 |pages=27591–27593 |access-date=September 27, 2012 |archive-date=July 10, 2017 |archive-url=https://web.archive.org/web/20170710130043/https://www.gpo.gov/fdsys/pkg/FR-2012-05-11/pdf/2012-11390.pdf |url-status=live }} However, unlike other countries, the United States classifies sunscreen as an over-the-counter drug rather than a cosmetic product. As FDA approval of a new drug is typically far slower than for a cosmetic, the result is fewer ingredients available for sunscreen formulations in the US compared with many other countries.{{cite journal | vauthors = Narla S, Lim HW | title = Sunscreen: FDA regulation, and environmental and health impact | journal = Photochemical & Photobiological Sciences | volume = 19 | issue = 1 | pages = 66–70 | date = January 2020 | pmid = 31845952 | doi = 10.1039/c9pp00366e | url = https://pubmed.ncbi.nlm.nih.gov/31845952 | access-date = February 20, 2023 | url-status = live | s2cid = 209388568 | archive-url = https://web.archive.org/web/20230425013950/http://pubmed.ncbi.nlm.nih.gov/31845952/ | archive-date = April 25, 2023 }}{{cite journal | vauthors = Ma Y, Yoo J | title = History of sunscreen: An updated view | journal = Journal of Cosmetic Dermatology | volume = 20 | issue = 4 | pages = 1044–1049 | date = April 2021 | pmid = 33583116 | doi = 10.1111/jocd.14004 | url = https://pubmed.ncbi.nlm.nih.gov/33583116 | access-date = February 20, 2023 | url-status = live | s2cid = 231928055 | archive-url = https://web.archive.org/web/20230203152721/https://pubmed.ncbi.nlm.nih.gov/33583116/ | archive-date = February 3, 2023 }} [426] => [427] => In 2019, the FDA proposed tighter regulations on sun protection and general safety, including the requirement that sunscreen products with SPF greater than 15 must be broad spectrum, and imposing a prohibition on products with SPF greater than 60.{{cite news | vauthors = LaMotte S |date=May 21, 2019 |title=Majority of sunscreens could flunk proposed FDA standards for safety and efficacy, report to say |work=[[CNN]] |url=https://www-m.cnn.com/2019/05/15/health/sunscreen-fda-safety-standards-study/index.html?r=https%3A%2F%2Fwww.cnn.com%2Fsearch%2F%3Fq%3DSunscreen |access-date=May 27, 2019 |archive-date=June 8, 2019 |archive-url=https://web.archive.org/web/20190608221932/https://www-m.cnn.com/2019/05/15/health/sunscreen-fda-safety-standards-study/index.html?r=https%3A%2F%2Fwww.cnn.com%2Fsearch%2F%3Fq%3DSunscreen |url-status=live }} [428] => [429] => * To be classified as "broad spectrum", sunscreen products must provide protection against both [[Ultraviolet A|UVA]] and [[UVB]], with specific tests required for both. [430] => * Claims of products being "[[waterproof]]" or "sweatproof" are prohibited, while the terms "sunblock" and "instant protection" and "protection for more than 2 hours" are all prohibited without specific FDA approval. [431] => * "Water resistance" claims on the front label must indicate how long the sunscreen remains effective and specify whether this applies to swimming or sweating, based on standard testing. [432] => * Sunscreens must include standardized "Drug Facts" information on the container. However, there is no regulation that deems it necessary to mention whether the contents contain [[nanoparticles]] of mineral ingredients. Furthermore, US products do not require the expiration date of products to be displayed on the label.{{cite journal | vauthors = Geoffrey K, Mwangi AN, Maru SM | title = Sunscreen products: Rationale for use, formulation development and regulatory considerations | journal = Saudi Pharmaceutical Journal | volume = 27 | issue = 7 | pages = 1009–1018 | date = November 2019 | pmid = 31997908 | pmc = 6978633 | doi = 10.1016/j.jsps.2019.08.003 }} [433] => [434] => In 2021, the FDA introduced an additional administrative order regarding the safety classification of cosmetic UV filters, to categorize a given ingredient as either: [435] => [436] => * Generally recognized as safe and effective ([[Generally recognized as safe and effective|GRASE]]) [437] => * Not GRASE due to safety issues [438] => * Not GRASE because additional safety data are needed. [439] => [440] => To be considered a GRASE active ingredient, the FDA requires it to have undergone both non-clinical animal studies as well as human clinical studies. The animal studies evaluate the potential for inducing carcinogenesis, genetic or reproductive harm, and any toxic effects of the ingredient once absorbed and distributed in the body. The human trials expand upon the animal trials, providing additional information on safety in the pediatric population, protection against UVA and UVB, and the potential for skin reactions after application. Two previously approved UV filters, para-aminobenzoic acid (PABA) and trolamine salicylate, were reclassified as ''not GRASE'' due to safety concerns and have consequently been removed from the market. [441] => [442] => '''Europe''' [443] => [444] => In Europe, sunscreens are considered a cosmetic product rather than an over-the-counter drug. These products are regulated by the Cosmetic Regulation (EC) No 1223/2009, which was created in July 2013. The recommendations for formulating sunscreen products are guided by the Scientific Community on Consumer Safety (SCCS).{{cite book | vauthors = Pirotta G |title=Sunscreens in Coastal Ecosystems |chapter=Sunscreen Regulation in the World |date=2020 |series=The Handbook of Environmental Chemistry |volume=94 |pages=15–35 |place=Cham |publisher=Springer International Publishing |doi=10.1007/698_2019_440 |isbn=978-3-030-56076-8 |s2cid=219055314 }} The regulation of cosmetic products in Europe requires the producer to follow six domains when formulating their product: [445] => [446] => I. Cosmetic safety report must be conducted by a qualified personnel [447] => [448] => II. The product must not contain substances banned for cosmetic products [449] => [450] => III. The product must not contain substances restricted for cosmetic products [451] => [452] => IV. The product must adhere to the approved list of colourants for cosmetic products. [453] => [454] => V. The product must adhere to the approved list of preservatives for cosmetic products. [455] => [456] => VI. The product must contain UV filters approved in Europe. [457] => [458] => According to the EC, sunscreens at a minimum must exhibit: [459] => [460] => # A SPF of 6 [461] => # UVA/UVB ratio ≥ 1/3 [462] => # The critical wavelength is at least 370 nanometers (indicating that it is "broad-spectrum"). [463] => # Instructions for using and precautions. [464] => # Evidence the sunscreen meets UVA and SPF requirements. [465] => # Labels of European sunscreens must disclose the use of nanoparticles in addition to the shelf life of the product. [466] => [467] => '''Canada''' [468] => [469] => Regulation of sunscreen is dependent on the ingredient used; It is then classified and follows the regulations for either natural health products or drug product. Companies must complete a product licensing application prior to introducing their sunscreen on the market. [470] => [471] => '''ASEAN (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, Vietnam)''' [472] => [473] => The regulation of sunscreen for ASEAN countries closely follows European regulations. However, products are regulated by the ASEAN scientific community rather than the SCCS. Additionally, there are minor differences in the allowed phrasing printed on sunscreen packages. [474] => [475] => '''Japan''' [476] => [477] => Sunscreen is considered a cosmetic product, and is regulated under the Japan Cosmetic Industry Association (JCIA). Products are regulated mostly for the type of UV filter and SPF. SPF may range from 2 to 50. [478] => [479] => '''China''' [480] => [481] => Sunscreen is regulated as cosmetic product under the State Food and Drug Administration (SFDA). The list of approved filters is the same as it is in Europe. However, sunscreen in China requires safety testing in animal studies prior to approval. [482] => [483] => '''Australia''' [484] => [485] => Sunscreens are divided into therapeutic and cosmetic sunscreens. Therapeutic sunscreens are classified into primary sunscreens (SPF ≥ 4) and secondary sunscreens (SPF < 4). Therapeutic sunscreens are regulated by the Therapeutic Goods Administration (TGA). Cosmetic sunscreens are products that contain a sunscreen ingredient, but do not protect from the sun. These products are regulated by the National Industrial Chemicals Notification and Assessment Scheme (NICNAS). [486] => [487] => '''New Zealand''' [488] => [489] => Sunscreen is classified as a cosmetic product, and closely follows EU regulations. However, New Zealand has a more extensive list of approved UV filters than Europe. [490] => [491] => '''Mercosur''' [492] => [493] => [[Mercosur]] is an international group consisting of Argentina, Brazil, Paraguay, and Uruguay. Regulation of sunscreen as a cosmetic product began in 2012, and is similar in structure to the European regulations. Sunscreens must meet specific standards including water resistance, sun protection factor, and a UVA/UVB ratio of 1/3. The list of approved sunscreen ingredients is greater than in Europe or the US. [494] => [495] => == Environmental effects == [496] => Some sunscreen active ingredients have been shown to cause toxicity towards marine life and coral, resulting in bans in different states, countries and ecological areas.{{cite journal | vauthors = Raffa RB, Pergolizzi JV, Taylor R, Kitzen JM | title = Sunscreen bans: Coral reefs and skin cancer | journal = Journal of Clinical Pharmacy and Therapeutics | volume = 44 | issue = 1 | pages = 134–139 | date = February 2019 | pmid = 30484882 | doi = 10.1111/jcpt.12778 | doi-access = free }}{{cite journal | vauthors = Downs CA, Kramarsky-Winter E, Segal R, Fauth J, Knutson S, Bronstein O, Ciner FR, Jeger R, Lichtenfeld Y, Woodley CM, Pennington P, Cadenas K, Kushmaro A, Loya Y | display-authors = 6 | title = Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands | journal = Archives of Environmental Contamination and Toxicology | volume = 70 | issue = 2 | pages = 265–288 | date = February 2016 | pmid = 26487337 | doi = 10.1007/s00244-015-0227-7 | bibcode = 2016ArECT..70..265D | url = https://repository.library.noaa.gov/view/noaa/13720 | url-status = live | access-date = April 2, 2023 | s2cid = 4243494 | archive-url = https://web.archive.org/web/20230330135416/https://repository.library.noaa.gov/view/noaa/13720 | archive-date = March 30, 2023 }} Coral reefs, comprising organisms in delicate ecological balances, are vulnerable to even minor environmental disturbances. Factors like temperature changes, invasive species, pollution, and detrimental fishing practices have previously been highlighted as threats to coral health.{{cite news | vauthors = Beitsch R |title=Some Sunscreens May Kill Corals. Should They Be Banned? |url=https://www.pewtrusts.org/en/research-and-analysis/blogs/stateline/2019/03/07/some-sunscreens-may-kill-corals-should-they-be-banned |url-status=live |access-date=April 24, 2019 |archive-url=https://web.archive.org/web/20190914204854/https://www.pewtrusts.org/en/research-and-analysis/blogs/stateline/2019/03/07/some-sunscreens-may-kill-corals-should-they-be-banned |archive-date=September 14, 2019}}{{Cite web |title=What is coral bleaching? |url=https://oceanservice.noaa.gov/facts/coral_bleach.html |url-status=live |archive-url=https://web.archive.org/web/20201220021310/https://oceanservice.noaa.gov/facts/coral_bleach.html |archive-date=December 20, 2020 |access-date=2019-04-07 |publisher=[[National Oceanic and Atmospheric Administration]] |language=EN-US}} [497] => [498] => In 2018, Hawaii passed a legislation that prohibits the sale of sunscreens containing [[oxybenzone]] and [[octinoxate]]. These chemicals, based on different researches, have been found to negatively impact coral reefs. In sufficient concentrations, these compounds can damage coral DNA, induce deformities in juvenile corals, heighten the risk of viral infections, and make corals more vulnerable to bleaching. Such threats are even more concerning given that coral ecosystems are already compromised by climate change, pollution, and other environmental stressors. While there is ongoing debate regarding the real-world concentrations of these chemicals versus laboratory settings,{{Cite web |title=Coral decline—is sunscreen a scapegoat? |url=https://phys.org/news/2021-02-coral-declineis-sunscreen-scapegoat.html |url-status=live |archive-url=https://web.archive.org/web/20211027152919/https://phys.org/news/2021-02-coral-declineis-sunscreen-scapegoat.html |archive-date=October 27, 2021 |access-date=2021-10-27 |website=phys.org |language=en}}{{cite journal | vauthors = Sirois J | title = Examine all available evidence before making decisions on sunscreen ingredient bans | journal = The Science of the Total Environment | volume = 674 | pages = 211–212 | date = July 2019 | pmid = 31004897 | doi = 10.1016/j.scitotenv.2019.04.137 | url = https://linkinghub.elsevier.com/retrieve/pii/S004896971931664X | url-status = live | access-date = October 27, 2021 | bibcode = 2019ScTEn.674..211S | s2cid = 125082651 | archive-url = https://web.archive.org/web/20220617160529/https://linkinghub.elsevier.com/retrieve/pii/S004896971931664X | archive-date = June 17, 2022 }}{{cite web |author= |date=1 April 2019 |title=New study measures UV-filters in seawater and corals from Hawaii |url=https://www.umces.edu/content/new-study-measures-uv-filters-seawater-and-corals-hawaii |url-status=live |archive-url=https://web.archive.org/web/20191217011800/https://www.umces.edu/content/new-study-measures-uv-filters-seawater-and-corals-hawaii |archive-date=December 17, 2019 |access-date=2019-06-20 |publisher=University of Maryland Center for Environmental Science}}{{cite journal | vauthors = Mitchelmore CL, He K, Gonsior M, Hain E, Heyes A, Clark C, Younger R, Schmitt-Kopplin P, Feerick A, Conway A, Blaney L | display-authors = 6 | title = Occurrence and distribution of UV-filters and other anthropogenic contaminants in coastal surface water, sediment, and coral tissue from Hawaii | journal = The Science of the Total Environment | volume = 670 | pages = 398–410 | date = June 2019 | pmid = 30904653 | doi = 10.1016/j.scitotenv.2019.03.034 | bibcode = 2019ScTEn.670..398M | s2cid = 85496503 }} an assesment in Kahaluu Bay in Hawaii showed oxybenzone concentrations to be 262 times higher than what the U.S. Environmental Protection Agency designates as high-risk. Another study in Hanauma Bay found levels of the chemical ranging from 30 ng/L to 27,880 ng/L, noting that concentrations beyond 63 ng/L could induce toxicity in corals.{{Cite journal | vauthors = Levine A | date = July 2020 |title=Sunscreen use and awareness of chemical toxicity among beach goers in Hawaii prior to a ban on the sale of sunscreens containing ingredients found to be toxic to coral reef ecosystems |journal=Marine Policy |volume=117 |pages=103875 |doi=10.1016/j.marpol.2020.103875 |s2cid=212872259 |issn=0308-597X|doi-access=free }} [499] => [500] => Echoing Hawaii's initiative, other regions including Key West, Florida, the U.S. Virgin Islands, Bonaire, and Palau{{Cite web |date=1 November 2018 |title=Coral: Palau to ban sunscreen products to protect reefs |url=https://www.bbc.com/news/science-environment-46046064 |url-status=live |archive-url=https://web.archive.org/web/20201122223903/https://www.bbc.com/news/science-environment-46046064 |archive-date=November 22, 2020 |access-date=January 2, 2020 |website=BBC News}} have also instituted bans on these harmful sunscreen chemicals. [501] => [502] => The environmental implications of sunscreen usage on marine ecosystems are multi-faceted and vary in severity. In a 2015 study, titanium dioxide, when introduced to water and subjected to ultraviolet light, was shown to amplify the production of hydrogen peroxide, a compound known to damage phytoplankton.{{cite journal | vauthors = Sánchez-Quiles D, Tovar-Sánchez A | title = Sunscreens as a source of hydrogen peroxide production in coastal waters | journal = Environmental Science & Technology | volume = 48 | issue = 16 | pages = 9037–9042 | date = August 2014 | pmid = 25069004 | doi = 10.1021/es5020696 | bibcode = 2014EnST...48.9037S | hdl-access = free | hdl = 10261/103567 }} In 2002, research indicated that sunscreens might escalate virus abundance in seawater, compromising the marine environment in a manner akin to other pollutants.{{cite journal | vauthors = Danovaro R, Corinaldesi C | title = Sunscreen products increase virus production through prophage induction in marine bacterioplankton | journal = Microbial Ecology | volume = 45 | issue = 2 | pages = 109–118 | date = February 2003 | pmid = 12545312 | doi = 10.1007/s00248-002-1033-0 | bibcode = 2003MicEc..45..109D | s2cid = 11379801 }} Further probing the matter, a 2008 investigation examining a variety of sunscreen brands, protective factors, and concentrations revealed unanimous bleaching effects on hard corals. Alarmingly, the degree of bleaching magnified with increasing sunscreen quantities. When assessing individual compounds prevalent in sunscreens, substances such as butylparaben, ethylhexylmethoxycinnamate, benzophenone-3, and 4-methylbenzylidene camphor induced complete coral bleaching at even minimal concentrations.{{cite journal | vauthors = Danovaro R, Bongiorni L, Corinaldesi C, Giovannelli D, Damiani E, Astolfi P, Greci L, Pusceddu A | display-authors = 6 | title = Sunscreens cause coral bleaching by promoting viral infections | journal = Environmental Health Perspectives | volume = 116 | issue = 4 | pages = 441–447 | date = April 2008 | pmid = 18414624 | pmc = 2291018 | doi = 10.1289/ehp.10966 }} [503] => [504] => A 2020 study from the journal Current Dermatology Report summarised the situation as the US FDA currently approves only zinc oxide (ZnO) and titanium dioxide (TiO2) as safe ultraviolet filters and for those concerned with coral bleaching they should use non-nano ZnO or TiO2, as they have the most consistent safety data.{{Cite journal | vauthors = Adler BL, DeLeo VA |date=2020-03-01 |title=Sunscreen Safety: a Review of Recent Studies on Humans and the Environment |url=https://doi.org/10.1007/s13671-020-00284-4 |journal=Current Dermatology Reports |language=en |volume=9 |issue=1 |pages=1–9 |doi=10.1007/s13671-020-00284-4 |s2cid=210671200 |issn=2162-4933}} [505] => [506] => == Research and Development == [507] => New products are in development such as sunscreens based on [[bioadhesive]] nanoparticles. These function by encapsulating commercially used UV filters, while being not only adherent to the skin but also non-penetrant. This strategy inhibits primary UV-induced damage as well as secondary free radicals.{{cite journal | vauthors = Deng Y, Ediriwickrema A, Yang F, Lewis J, Girardi M, Saltzman WM | title = A sunblock based on bioadhesive nanoparticles | journal = Nature Materials | volume = 14 | issue = 12 | pages = 1278–1285 | date = December 2015 | pmid = 26413985 | pmc = 4654636 | doi = 10.1038/nmat4422 | bibcode = 2015NatMa..14.1278D }} UV filters based on [[Sinapinic acid|sinapate]] [[ester]]s are also under study.{{cite journal | vauthors = Horbury MD, Holt EL, Mouterde LM, Balaguer P, Cebrián J, Blasco L, Allais F, Stavros VG | display-authors = 6 | title = Towards symmetry driven and nature inspired UV filter design | journal = Nature Communications | volume = 10 | issue = 1 | pages = 4748 | date = October 2019 | pmid = 31628301 | pmc = 6802189 | doi = 10.1038/s41467-019-12719-z | s2cid = 204757709 | bibcode = 2019NatCo..10.4748H }} Sunscreens with natural and sustainable connotations are increasingly being developed, as a result of increased environmental concern.{{Cite journal |last1=Tortini |first1=Guido |last2=Ziosi |first2=Paola |last3=Cesa |first3=Elena |last4=Molesini |first4=Sonia |last5=Baldini |first5=Erika |last6=De Lucia |first6=Daniela |last7=Rossi |first7=Caterina |last8=Durini |first8=Elisa |last9=Vertuani |first9=Silvia |last10=Manfredini |first10=Stefano |date=June 2022 |title=Criticisms in the Development of High-Protection and Broad-Spectrum "Natural/Organic" Certifiable Sunscreen |journal=Cosmetics |language=en |volume=9 |issue=3 |pages=56 |doi=10.3390/cosmetics9030056 |issn=2079-9284 |doi-access=free |hdl=11392/2496193 |hdl-access=free }} [508] => [509] => == Note == [510] => {{notelist}} [511] => [512] => == References == [513] => {{Reflist}} [514] => [515] => == External links == [516] => * [https://www.wired.com/story/whats-deal-with-sunscreen-does-it-work-or-not Does it work, or not?] – illustrated explanation of how UV light is absorbed by chemicals in sunscreen from [[Wired (magazine)|''Wired'']] [517] => *[https://thedermreview.com/sunscreen-survey 56% of Americans Rarely or Never Use Sunscreen] – A survey conducted about the sunscreen habits of modern Americans. [518] => [519] => {{Sunscreening agents}} [520] => {{Authority control}} [521] => [522] => [[Category:Sunscreening agents| ]] [523] => [[Category:Australian inventions]] [524] => [[Category:Skin care]] [525] => [[Category:Environment articles needing expert attention]] [] => )
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Sunscreen

Sunscreen is a product designed to protect the skin from harmful ultraviolet (UV) radiation present in sunlight. It is typically applied topically and acts as a physical or chemical barrier to prevent UV rays from damaging the skin.

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It is typically applied topically and acts as a physical or chemical barrier to prevent UV rays from damaging the skin. Sunscreens contain various ingredients, including organic or inorganic compounds, that absorb, scatter, or reflect UV radiation. They are available in different forms such as lotions, creams, gels, sticks, sprays, and powders. The primary purpose of sunscreen is to reduce the risk of sunburn, skin cancer, premature aging, and other sun-related skin damage. UV radiation consists of UVA, which causes long-term skin aging, and UVB, which primarily causes sunburns. Sunscreens provide protection against both types of radiation, but the level of protection is determined by the product's Sun Protection Factor (SPF). SPF measures the UVB protection effectiveness, with higher numbers indicating greater protection. In addition to UV protection, some sunscreens also offer protection against UVC radiation and other environmental factors such as pollution. They may contain additional ingredients like antioxidants to neutralize free radicals generated by UV radiation. The history of sunscreen dates back to ancient civilizations, with various cultures using natural substances like plant oils and extracts to shield the skin from sun damage. Modern sunscreen development began in the early 20th century, evolving into more advanced formulations and standardized testing protocols. Controversies surrounding sunscreen include concerns over certain ingredients' safety, their impact on marine ecosystems, and conflicting research on their effectiveness against certain types of skin cancer. There are also debates about the efficacy and potential harm of chemical sunscreens compared to mineral-based alternatives. Overall, sunscreen plays a crucial role in protecting the skin from harmful UV radiation, promoting skin health, and reducing the risk of sun-related disorders. Proper and frequent use of sunscreen, combined with other sun-safe practices like seeking shade and wearing protective clothing, is recommended for maintaining skin health and preventing sun damage.

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