Sunless tanning

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1960s advertisement for tanning lotion

Sunless tanning, also known as UV filled tanning, self tanning, spray tanning (when applied topically), or fake tanning, refers to the effect of a suntan without exposure to the Sun. Sunless tanning involves the use of oral agents (carotenids), or creams, lotions or sprays applied to the skin.[1] Skin-applied products may be skin-reactive agents or temporary bronzers (colorants).

The popularity of sunless tanning has risen since the 1960s after health authorities confirmed links between UV exposure (from sunlight or tanning beds) and the incidence of skin cancer.

The chemical compound dihydroxyacetone (DHA) is used in sunless tanning products in concentrations of 3%-5%.[2] DHA concentration is adjusted to provide darker and lighter shades of tan. The reaction of keratin protein present in skin and DHA is responsible for the production of pigmentation.[3]

Oral agents (carotenoids)[edit]

A safe and effective method of sunless tanning is consumption of certain carotenoids[4][5][6]antioxidants found in some fruits and vegetables such as carrots and tomatoes—which can result in changes to skin color when ingested chronically and/or in high amounts. Carotenoids are long-lasting. In addition, carotenoids have been linked to a more attractive skin tone (defined as a more golden skin color) than suntan.[7] Carotenes also fulfil the function of melanin in absorbing the UV radiation and protecting the skin.[8] For example, they are concentrated in the macula of the eye to protect the retina from damage. They are used in plants both to protect chlorophyll from light damage and harvest light directly.[9]

Carotenaemia (xanthaemia) is the presence in blood of the yellow pigment carotene from excessive intake of carrots or other vegetables containing the pigment resulting in increased serum carotenoids. It can lead to subsequent yellow-orange discoloration (xanthoderma or carotenoderma) and their subsequent deposition in the outermost layer of skin. Carotenemia and carotenoderma is in itself harmless, and does not require treatment. In primary carotenoderma, when the use of high quantities of carotene is discontinued the skin color will return to normal. It may take up to several months, however, for this to happen.[citation needed]

Lycopene[edit]

Lycopene is a key intermediate in the biosynthesis of beta-carotene and xanthophylls.

Lycopene may be the most powerful carotenoid quencher of singlet oxygen.[10]

Due to its strong color and non-toxicity, lycopene is a useful food coloring (registered as E160d) and is approved for usage in the US,[11] Australia and New Zealand (registered as 160d)[12] and the EU.[13]

Beta-carotene[edit]

Sunless-tanning pills often contain β-carotene. The American Cancer Society states that "Although the US Food and Drug Administration (FDA) has approved some of these additives for coloring food, they are not approved for use in tanning agents." Also that "They may be harmful at the high levels that are used in tanning pills."[14]

Chronic, high doses of synthetic β-carotene supplements have been associated with increased rate of lung cancer among those who smoke.[15]

Canthaxanthin[edit]

Canthaxanthin is most commonly used as a color additive in certain foods. Although the FDA has approved the use of canthaxanthin in food, it does not approve its use as a tanning agent. When used as a color additive, only very small amounts of canthaxanthin are needed. As a tanning agent, however, much larger quantities are used. After canthaxanthin is consumed, it is deposited throughout the body, including in the layer of fat below the skin, which turns an orange-brown color. These types of tanning pills have been linked to various side effects, including hepatitis and canthaxanthin retinopathy, a condition in which yellow deposits form in the retina of the eye. Other side effects including damage to the digestive system and skin surface have also been noted.[citation needed] The FDA withdrew approval for use of canthaxanthin as a tanning agent, and has issued warnings concerning its use.[16]

Skin-reactive agents[edit]

DHA-based products[edit]

DHA (dihydroxyacetone, also known as glycerone) is not a dye, stain or paint, but causes a chemical reaction with the amino acids in the dead layer on the skin surface. One of the pathways is a free radical-mediated Maillard reaction.[17][18] The other pathway is the conventional Maillard reaction, a process well known to food chemists that causes the browning that occurs during food manufacturing and storage. It does not involve the underlying skin pigmentation nor does it require exposure to ultraviolet light to initiate the color change. However, for the 24 hours after self-tanner is applied, the skin is especially susceptible to ultraviolet, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin.[19] Forty minutes after the researchers treated skin samples with high levels of DHA they found that more than 180 percent additional free radicals formed during sun exposure compared with untreated skin. Another self-tanner ingredient, erythrulose, produced a similar response at high levels. For a day after self-tanner application, excessive sun exposure should be avoided and sunscreen should be worn outdoors, they say; an antioxidant cream could also minimize free radical production. Although some self-tanners contain sunscreen, its effect will not last long after application, and a fake tan itself will not protect the skin from UV exposure. The study by Jung et al. further confirms earlier results demonstrating that dihydroxyacetone in combination with dimethylisosorbide enhances the process of (sun-based) tanning. This earlier study also found that dihydroxyacetone also has an effect on the amino acids and nucleic acids which is bad for the skin.[20]

The free radicals are due to the action of UV light on AGE (advanced glycation end-products) as a result of the reaction of DHA with the skin, and the intermediates, such as Amadori products (a type of AGE), that lead to them. AGEs are behind the damage to the skin that occurs with high blood sugar in diabetes where similar glycation occurs.[21] AGEs absorb and provide a little protection against some of the damaging factors of UV (up to SPF 3),[22][23] However, they do not have melanin's extended electronic structure that dissipates the energy, so part of it goes towards starting free radical chain reactions instead, in which other AGEs participate readily. Overall tanner enhances free radical injury.[19] Although some self-tanners contain sunscreen, its effect will not last as long as the tan. The stated SPF is only applicable for a few hours after application. Despite darkening of the skin, an individual is still susceptible to UV rays, therefore an overall sun protection is still very necessary.[24] There may also be some inhibition of vitamin D production in DHA-treated skin.[25]

The color effect is temporary and fades gradually over 3 to 10 days. Some of these products also use erythrulose which works identically to DHA, but develops more slowly. Both DHA and erythrulose have been known to cause contact dermatitis.

Professional spray tan applications are available from spas, salons and gymnasiums by both hand-held sprayers and in the form of sunless or UV-Free spray booths. Spray tan applications are also available through online retail distribution channels and are widely available to purchase for in home use.[26] The enclosed booth, which resembles an enclosed shower stall, sprays the tanning solution over the entire body. The U.S. Food and Drug Administration (FDA) states when using DHA-containing products as an all-over spray or mist in a commercial spray "tanning" booth, it may be difficult to avoid exposure in a manner for which DHA is not approved, including the area of the eyes, lips, or mucous membrane, or even internally. DHA is not approved by the FDA for inhalation.[26]

An opinion[27] issued by the European Commission's Scientific Committee on Consumer Safety, concluding spray tanning with DHA did not pose risk, has been heavily criticized by specialists.[28] This is because the cosmetics industry in Europe chose the evidence to review, according to the commission itself. Thus, nearly every report the commission's eventual opinion referenced came from studies that were never published or peer-reviewed and, in the majority of cases, were performed by companies or industry groups linked to the manufacturing of DHA. The industry left out nearly all of the peer-reviewed studies published in publicly available scientific journals that identified DHA as a potential mutagen. A study by scientists from the Department of Dermatology, Bispebjerg Hospital, published in Mutation Research has concluded DHA 'induces DNA damage, cell-cycle block and apoptosis' in cultured cells.[29]

SIK-inhibitors[edit]

A novel class of compounds has been found to stimulate melanogenesis in a mechanism that is independent from α-melanocyte-stimulating hormone (α-MSH) activation of the melanocortin 1 receptor (MC1 receptor). This is accomplished via small molecule inhibition of salt-inducible kinases (SIK). Inhibition of SIK increases transcription of MITF which is known to increase melanin production. Work published in June 2017 has demonstrated compounds that have efficacy when applied topically to human skin.[30] These compounds are still however in pre-clinical stages of development. Future directions may include the incorporation of SIK-inhibitor compounds with traditional UV-blocking sunscreens to minimize UV-related DNA damage in the short term while providing longer term protection through endogenous melanin production.

Tyrosine-based products[edit]

Tanning accelerators—lotions or pills[16] that usually contain the amino acid tyrosine—claim that they stimulate and increase melanin formation, thereby accelerating the tanning process. These are used in conjunction with UV exposure. At this time, there is no scientific data available to support these claims.

Melanotan peptide hormones[edit]

The role of alpha-melanocyte-stimulating hormone (α-MSH) in promoting melanin diffusion has been known since the 1960s.[31] In the 1980s, scientists at University of Arizona began attempting to develop α-MSH and analogs as potential sunless tanning agents, and synthesized and tested several analogs, including afamelanotide, then called melanotan-I.[32]

To pursue the tanning agent, melanotan-I was licensed by Competitive Technologies, a technology transfer company operating on behalf of University of Arizona, to an Australian startup called Epitan,[33][32] which changed its name to Clinuvel in 2006.[34]

A number of products are sold online and in gyms and beauty salons as "melanotan" or "melanotan-1" which discuss afamelanotide in their marketing.[35][36][37]

The products are not legal in any jurisdiction and are dangerous.[38][39][40][41]

Starting in 2007 health agencies in various counties began issuing warnings against their use.[42][43][44][45][46][47]

Other melanogenesis stimulants[edit]

Eicosanoids, retinoids, oestrogens, melanocyte-stimulating hormone, endothelins, psoralens, hydantoin, forskolin, cholera toxin, isobutylmethylxanthine, diacylglycerol analogues, and UV irradiation all trigger melanogenesis and, in turn, pigmentation.

Temporary bronzers (skin colorants)[edit]

Bronzers are a temporary sunless tanning or bronzing option. These come in powders, sprays, mousse, gels, lotions and moisturizers. Once applied, they create a tan that can easily be removed with soap and water. Like make-up, these products tint or stain a person's skin only until they are washed off.

They are often used for "one-day" only tans, or to complement a DHA-based sunless tan. Many formulations are available, and some have limited sweat or light water resistance. If applied under clothing, or where fabric and skin edges meet, most will create some light but visible rub-off. Dark clothing prevents the rub-off from being noticeable. While these products are much safer than tanning beds, the color produced can sometimes look orangey and splotchy if applied incorrectly.

A recent trend is that of lotions or moisturizers containing a gradual tanning agent. A slight increase in color is usually observable after the first use, but color will continue to darken the more frequently the product is used.

Just as with the term "sunless tanner", the term "bronzer" is likewise not defined by law, or by regulations enforced by the FDA. What is defined and regulated is the color additive DHA, or dihydroxyacetone.[48] (Note that the "color additive" dihydroxyacetone is itself colorless.)[49]

Air brush tanning is a spray on tan performed by a professional. An air brush tan can last five to ten days and will fade when the skin is washed. It is used for special occasions or to get a quick dark tan. At-home airbrush tanning kits and aerosol mists are also available.

Risks[edit]

Tanners usually contain a sunscreen. However, when avobenzone is irradiated with UVA light, it generates a triplet excited state in the keto form which can either cause the avobenzone to degrade or transfer energy to biological targets and cause deleterious effects.[50] It has been shown to degrade significantly in light, resulting in less protection over time.[51][52][53] The UV-A light in a day of sunlight in a temperate climate is sufficient to break down most of the compound. It's important to continue wearing SPF while self-tanning, as self-tanner is generally a fake and temporary tan, and your skin is still sensitive to the sun.[citation needed]

If avobenzone-containing sunscreen is applied on top of tanner, the photosensitizer effect magnifies the free-radical damage promoted by DHA, as DHA may make the skin especially susceptible to free-radical damage from sunlight, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin.[19] Forty minutes after the researchers treated skin samples with 20% DHA they found that more than 180 percent additional free radicals formed during sun exposure compared with untreated skin.

A toxicologist and lung specialist at the University of Pennsylvania's Perelman School of Medicine (Dr. Rey Panettieri) has commented, "The reason I'm concerned is the deposition of the tanning agents into the lungs could really facilitate or aid systemic absorption -- that is, getting into the bloodstream. These compounds in some cells could actually promote the development of cancers or malignancies, and if that's the case then we need to be wary of them."[54] A study by scientists from the Department of Dermatology, Bispebjerg Hospital, published in Mutation Research has concluded DHA 'induces DNA damage, cell-cycle block and apoptosis' in cultured cells.[29]

Many self tanners use chemical fragrances which may cause skin allergies or may trigger asthma. Furthermore, some of them contain parabens. Parabens are preservatives that can affect the endocrine system.[55]

See also[edit]

References[edit]

  1. ^ "Sunless tanning: What you need to know". Mayo Clinic. 30 May 2017. Archived from the original on 24 May 2019.
  2. ^ Zoe Kececioglu Draelos. (2019). Cosmetics and dermatologic problems and solutions. Boca Raton: Crc Press.
  3. ^ James Rippe. (2013). Lifestyle Medicine, Second Edition. Editorial: Crc Press.
  4. ^ Stahl W, Heinrich U, Aust O, Tronnier H, Sies H (February 2006). "Lycopene-rich products and dietary photoprotection". Photochemical & Photobiological Sciences. 5 (2): 238–42. doi:10.1039/b505312a. PMID 16465309. S2CID 17706826.Closed access icon
  5. ^ Stahl W, Heinrich U, Wiseman S, Eichler O, Sies H, Tronnier H (May 2001). "Dietary tomato paste protects against ultraviolet light-induced erythema in humans". The Journal of Nutrition. 131 (5): 1449–51. doi:10.1093/jn/131.5.1449. PMID 11340098.
  6. ^ Stahl W, Sies H (2002). "Carotenoids and protection against solar UV radiation". Skin Pharmacology and Applied Skin Physiology. 15 (5): 291–6. doi:10.1159/000064532. PMID 12239422. S2CID 10464154.Closed access icon
  7. ^ Dolan, Eric W., ed. (11 January 2011). "Carotenoids linked to attractive skin tone". PsyPost.
  8. ^ Stahl W, Sies H (November 2012). "β-Carotene and other carotenoids in protection from sunlight". The American Journal of Clinical Nutrition. 96 (5): 1179S–84S. doi:10.3945/ajcn.112.034819. PMID 23053552.
  9. ^ Armstrong GA, Hearst JE (1996). "Carotenoids 2: Genetics and molecular biology of carotenoid pigment biosynthesis". The FASEB Journal. 10 (2): 228–37. doi:10.1096/fasebj.10.2.8641556. PMID 8641556. S2CID 22385652.
  10. ^ Di Mascio, Paolo; Kaiser, Stephan; Sies, Helmut (1989). "Lycopene as the most efficient biological carotenoid singlet oxygen quencher". Archives of Biochemistry and Biophysics. 274 (2): 532–538. doi:10.1016/0003-9861(89)90467-0. ISSN 0003-9861. OCLC 4922826134. PMID 2802626.
  11. ^ "21CFR73.585". www.accessdata.fda.gov. CFR - Code of Federal Regulations Title 21. Archived from the original on 27 September 2006. Retrieved 4 June 2018.
  12. ^ Australia New Zealand Food Standards Code"Standard 1.2.4 - Labelling of ingredients". 8 September 2011. Retrieved 27 October 2011.
  13. ^ UK Food Standards Agency: "Current EU approved additives and their E Numbers". Retrieved 27 October 2011.
  14. ^ "Tanning pills and accelerators". Retrieved 1 April 2018.
  15. ^ Tanvetyanon T, Bepler G (July 2008). "Beta-carotene in multivitamins and the possible risk of lung cancer among smokers versus former smokers: a meta-analysis and evaluation of national brands". Cancer. 113 (1): 150–7. doi:10.1002/cncr.23527. PMID 18429004. S2CID 33827601.
  16. ^ a b "US FDA/CFSAN - Tanning Pills". Food and Drug Administration.
  17. ^ Namiki, Mitsuo; Hayashi, Tateki (1983). "A New Mechanism of the Maillard Reaction Involving Sugar Fragmentation and Free Radical Formation". The Maillard Reaction in Foods and Nutrition. ACS Symposium Series. Vol. 215. pp. 21–46. doi:10.1021/bk-1983-0215.ch002. ISBN 978-0-8412-0769-1.
  18. ^ Lloyd, Roger V; Fong, Anna J; Sayre, Robert M (2001). "In Vivo Formation of Maillard Reaction Free Radicals in Mouse Skin". Journal of Investigative Dermatology. 117 (3): 740–2. doi:10.1046/j.0022-202x.2001.01448.x. PMID 11564185.
  19. ^ a b c Jung K, Seifert M, Herrling T, Fuchs J (May 2008). "UV-generated free radicals (FR) in skin: their prevention by sunscreens and their induction by self-tanning agents". Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 69 (5): 1423–8. Bibcode:2008AcSpA..69.1423J. doi:10.1016/j.saa.2007.09.029. PMID 18024196.
  20. ^ Benamar N, Laplante AF, Lahjomri F, Leblanc RM (October 2004). "Modulated photoacoustic spectroscopy study of an artificial tanning on human skin induced by dihydroxyacetone". Physiological Measurement. 25 (5): 1199–210. Bibcode:2004PhyM...25.1199B. doi:10.1088/0967-3334/25/5/010. PMID 15535185. S2CID 20591508.
  21. ^ Oak J, Nakagawa K, Miyazawa T (September 2000). "Synthetically prepared Aamadori-glycated phosphatidylethanolaminecan trigger lipid peroxidation via free radical reactions". FEBS Letters. 481 (1): 26–30. doi:10.1016/S0014-5793(00)01966-9. PMID 10984609.
  22. ^ Faurschou A, Wulf HC (October 2004). "Durability of the sun protection factor provided by dihydroxyacetone". Photodermatology, Photoimmunology & Photomedicine. 20 (5): 239–42. doi:10.1111/j.1600-0781.2004.00118.x. PMID 15379873. S2CID 35465870.
  23. ^ Petersen AB, Na R, Wulf HC (December 2003). "Sunless skin tanning with dihydroxyacetone delays broad-spectrum ultraviolet photocarcinogenesis in hairless mice". Mutation Research. 542 (1–2): 129–38. doi:10.1016/j.mrgentox.2003.09.003. PMID 14644361.
  24. ^ "Dihydroxyacetone, tanning cream, sunless tanning. DermNet NZ". Dermnetnz.org. 29 August 2015. Retrieved 27 February 2016.
  25. ^ Armas LA, Fusaro RM, Sayre RM, Huerter CJ, Heaney RP (2009). "Do melanoidins induced by topical 9% dihydroxyacetone sunless tanning spray inhibit vitamin d production? A pilot study". Photochemistry and Photobiology. 85 (5): 1265–6. doi:10.1111/j.1751-1097.2009.00574.x. PMID 19496990. S2CID 6733532.
  26. ^ a b "FDA Comments on Sunless Tanners and Bronzers". Food and Drug Administration.
  27. ^ SCCS (Scientific Committee on Consumer Safety) (14 December 2010). Opinion on dihydroxyacetone (PDF). European Union. doi:10.2772/29632. ISBN 978-92-79-12767-0.
  28. ^ "Safety of Popular 'Spray On' Tans in Question; Are You Protected? - ABC News". Abcnews.go.com. 12 June 2012. Retrieved 27 February 2016.
  29. ^ a b Petersen, Anita B.; Wulf, Hans Christian; Gniadecki, Robert; Gajkowska, Barbara (13 June 2004). "Dihydroxyacetone, the active browning ingredient in sunless tanning lotions, induces DNA damage, cell-cycle block and apoptosis in cultured HaCaT keratinocytes". Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 560 (2): 173–186. doi:10.1016/j.mrgentox.2004.03.002. PMID 15157655. Retrieved 27 February 2016.
  30. ^ Mujahid, Nisma; Liang, Yanke; Murakami, Ryo; Choi, Hwan Geun; Dobry, Allison S.; Wang, Jinhua; Suita, Yusuke; Weng, Qing Yu; Allouche, Jennifer (13 June 2017). "A UV-Independent Topical Small-Molecule Approach for Melanin Production in Human Skin". Cell Reports. 19 (11): 2177–2184. doi:10.1016/j.celrep.2017.05.042. ISSN 2211-1247. PMC 5549921. PMID 28614705.
  31. ^ Baker, BI (31 May 1993). "The role of melanin-concentrating hormone in color change". Annals of the New York Academy of Sciences. 680 (1): 279–89. Bibcode:1993NYASA.680..279B. doi:10.1111/j.1749-6632.1993.tb19690.x. PMID 8390154. S2CID 11465789.
  32. ^ a b Hadley, ME; Dorr, RT (April 2006). "Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization". Peptides. 27 (4): 921–30. doi:10.1016/j.peptides.2005.01.029. PMID 16412534. S2CID 21025287.
  33. ^ "EpiTan focuses on Melanotan, a potential blockbuster". The Pharma Letter. 1 November 2004.
  34. ^ "Epitan changes name to Clinuvel, announces new clinical program". LabOnline. 27 February 2006.
  35. ^ "Believe It Or Not 'Tanorexia' A Very Real Problem". WCBS-TV, CBS. 20 May 2009. Archived from the original on 21 May 2009. Retrieved 23 July 2009.
  36. ^ "Fools Gold". Cosmopolitan (Australia). 14 June 2009. Archived from the original on 12 September 2009. Retrieved 25 July 2009.
  37. ^ Madrigal, Alexis (29 January 2009). "Suntan Drug Greenlighted for Trials". Wired. Archived from the original on 5 May 2009. Retrieved 11 April 2009.
  38. ^ "Tanning drug a health risk". Herald Sun. 31 October 2009. Retrieved 31 October 2009.
  39. ^ Ewan A Langan; Z. Nie; Lesley E Rhodes (June 2010). "Melanotropic peptides: More than just 'Barbie drugs' and 'sun tan jabs?'". British Journal of Dermatology. 163 (3): 451–5. doi:10.1111/j.1365-2133.2010.09891.x. PMID 20545686. S2CID 8203334.
  40. ^ Ewan A Langan; Denise Ramlogan; Lynne A Jamieson; Lesley E Rhodes (January 2009). "Change in moles linked to use of unlicensed "sun tan jab"". BMJ. 338: b277. doi:10.1136/bmj.b277. PMID 19174439. S2CID 27838904.
  41. ^ "Risky tan jab warnings 'ignored'". BBC. 18 February 2009. Archived from the original on 21 February 2009. Retrieved 4 March 2009.
  42. ^ "Warning against the product Melanotan". Danish Medicines Agency. 2008. Retrieved 11 August 2008.
  43. ^ ""Tan jab" is an unlicensed medicine and may not be safe". MHRA. 2008. Archived from the original on 18 December 2008. Retrieved 17 November 2008.
  44. ^ "US Lab Research Inc Warning letter". U.S. Food and Drug Administration. 29 January 2009. Archived from the original on 10 July 2009. Retrieved 23 July 2009.
  45. ^ "Melanotan Powder for Injection". Notice Information: – Warning – 27 February 2009. Irish Medicines Board. 2009. Retrieved 2 February 2009.
  46. ^ "Legemiddelverket advarer mot bruk av Melanotan". Norwegian Medicines Agency. 13 December 2007. Archived from the original on 17 April 2009. Retrieved 11 March 2009.
  47. ^ "Melanotan – farlig og ulovlig brunfarge". Norwegian Medicines Agency. 23 January 2009. Archived from the original on 17 April 2009. Retrieved 11 March 2009.
  48. ^ Nutrition, Center for Food Safety and Applied (11 September 2020). "Sunless Tanners & Bronzers". FDA – via www.fda.gov.
  49. ^ "DHA-Spray and Sunless Tanning Booths". MedicineNet.
  50. ^ Paris C, Lhiaubet-Vallet V, Jimenez O, Trullas C, Miranda M (January–February 2009). "A Blocked Diketo Form of Avobenzone: Photostability, Photosensitizing Properties and Triplet Quenching by a Triazine-derived UVB-filter". Photochemistry and Photobiology. 85 (1): 178–184. doi:10.1111/j.1751-1097.2008.00414.x. PMID 18673327.
  51. ^ Chatelain E; Gabard B. (September 2001). "Photostabilization of Butyl methoxydibenzoylmethane (Avobenzone) and Ethylhexyl methoxycinnamate by Bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a new UV broadband filter". Photochemistry and Photobiology. 74 (3): 401–6. doi:10.1562/0031-8655(2001)074<0401:POBMAA>2.0.CO;2 (inactive 25 March 2024). ISSN 0031-8655. PMID 11594052. S2CID 29879472.{{cite journal}}: CS1 maint: DOI inactive as of March 2024 (link)
  52. ^ Tarras-Wahlberg N, Stenhagen G, Larko O, Rosen A, Wennberg AM, Wennerstrom O (October 1999). "Changes in ultraviolet absorption of sunscreens after ultraviolet irradiation". J Invest Dermatol. 113 (4): 547–53. doi:10.1046/j.1523-1747.1999.00721.x. PMID 10504439.
  53. ^ Wetz F, Routaboul C, Denis A, Rico-Lattes I (March–April 2005). "A new long-chain UV absorber derived from 4-tert-butyl-4'-methoxydibenzoylmethane: absorbance stability under solar irradiation". Journal of Cosmetic Science. 56 (2): 135–48. doi:10.1562/2004-03-09-ra-106 (inactive 25 March 2024). PMID 15870853.{{cite journal}}: CS1 maint: DOI inactive as of March 2024 (link)
  54. ^ Greenblatt, Mark; Ahuja, Gitika (13 June 2012). "Are 'Spray-On' Tans Safe? Experts Raise Questions as Industry Puts Out Warnings". ABC News. Retrieved 4 June 2018.
  55. ^ Harvey, Philip W.; Everett, David J. (2004). "Significance of the detection of esters of p-hydroxybenzoic acid (parabens) in human breast tumours". Journal of Applied Toxicology. 24 (1): 1–4. doi:10.1002/jat.957. PMID 14745840. S2CID 29852495.

External links[edit]