Remembering the INCI names of sunscreen filters is impossible! Let alone sifting through the research & information about what they do. My dear friend, Dan Finaldi who has an unmatched passion and curiosity for sunscreen not to mention some real knowledge, compiled this thoughtful and valuable cheat sheet for me. This is so fabulously educational I have to share it with all of you fellow, skinthusiast, sunscreen geeks who just enjoy the details! 💋
At present, all commonly used sunscreen filters have favorable human safety profiles despite what you may have read/heard.
UVA Long-wavelength.
Can damage our skin’s DNA, which leads to signs of aging such as wrinkles. UVA is also responsible for hyperpigmentation. Can penetrate to and affect the deeper layers of the skin. May also promote the development of skin cancers.
UVB Short-wavelength.
Responsible for sunburn, skin aging and can promote the development of skin cancer. Doesn’t penetrate beyond the skin’s superficial layers.
BROAD SPECTRUM FILTERS
Tinosorb S
Bemotrizinol
INCI: Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine
A very efficient broad spectrum filter. It is a huge molecule that doesn’t seem to penetrate through the top layers of the skin. It is remarkably photostable, and can help to stabilize Avobenzone. It is often added to formulas at low concentrations, as it can boost the SPF and UVA protection of a formula.
Tinosorb A2B (nano)
INCI: Tris-Biphenyl Triazine (nano)
A new, efficient broad spectrum filter. So new, it isn’t found in many sunscreens at present. It is a nanosized, carbon based particle. It offers strong attenuance across the UV spectrum particularly in the wavelengths between UVA & UVB, known as the UVAII range. Can absorb and scatter UV rays.
Tinosorb M
Bisoctrizole
INCI: Methylene Bis-Benzotriazolyl Tetramethylbutylphenol
A broad spectrum sunscreen filter which is totally insoluble, and is suspended in a sunscreen products (just like zinc / titanium). It was the first organic sunscreen filter which was developed to block UV through scattering as well as through absorption (just like zinc/titanium). This can cause a cast.
Mexoryl XL
INCI: Drometrizole Trisiloxane
A molecule developed and patented by L’Oréal, and is used exclusively by their brands (Garnier, La Roche-Posay, and L’Oréal all have Mexoryl XL-containing sunscreens). It is a broad spectrum filter. It has good photostability. It is soluble in oil and is suitable in water-resistant formulations.
Zinc Oxide
A pretty inefficient broad spectrum filter, but is allowed at high concentrations in sunscreen formulae, allowing for high SPF sunscreens in which Zinc Oxide is the sole filter. It is insoluble, so it is dispersed as a suspension in sunscreens. It is photostable and is known to impart an opaque white cast on skin. It is available in a variety of forms – different coatings and particle sizes – all of which absorb UV differently. Smaller particles of zinc oxide leave a less significant white cast, and can be formulated into products with a more appealing texture. As the particle size of zinc decreases, so does its absorbance peak (it absorbs UVA less well), and scattering becomes a less significant part of its UV attenuation. Large particles of zinc oxide scatter more radiation and better attenuate longer frequencies of radiation.
UVA Filters
Avobenzone
A terrific UVA filter. It covers both UVAI (tanning) and UVAII (tanning and erythema). In the wrong formula, it is pretty photo-unstable. It can be made more photostable if dissolved in the right kind of solvent (octocrylene is popular) and included in a formula with photo stabilizing ingredients (Tinosorb S is helpful, as is naphthalene dicarboxylic acid).
Uvinul A Plus
INCI: Diethylamino Hydroxybenzoyl Hexyl Benzoate
A photostable UVA filter. It is pretty commonly used in sunscreens because of its photostablility and can be used in higher concentrations than Avobenzone, so it can be used to achieve high UVA protection. The manufacturer of DHHB actually sells it in a package with Octinoxate with instructions on how to achieve a high SPF sunscreen.
Ecamsule Mexoryl SX
A photostable UVA filter. Its absorbance peak is right on the border of UVAII and UVAI. It helps to stabilize Avobenzone. It was developed and patented by L’Oréal, and is available in sunscreens from L’Oréal brands. It is currently available in the US in one sunscreen – the La Roche-Posay Anthelios SX SPF 15.
Neo Heliopan AP
Neo Heliopan AP is a UVAII Filter. It is water soluble, so it can be used in lightweight formulations. On its own, it will not offer water resistance. It is a big molecule which is unlikely to penetrate the skin efficiently. It doesn’t offer strong attenuance of UVA I radiation, so it is usually used with other UVA filters to ensure broad-spectrum coverage.
UVB Filters
Uvinul T 150
Octyl Triazone
INCI: Ethylhexyl Triazone
A very efficient, photostable UVB filter. It’s very soluble in polar oils and has an affinity towards skin keratin, and is therefore a logical ingredient in water-resistant sunscreens.
Titanium Dioxide
An insoluble mineral filter, and is suspended in sunscreen formulae. It protects well against UVB and UVAII, and offers little UVA I protection. It has not been linked to harm to coral. Its photoexcitation can lead to the generation of free radicals if the titanium dioxide in a formula is of an insufficient grade. At large particulate sizes, it will leave an opaque white cast on the skin. As with Zinc Oxide, the specific Titanium Dioxide used by a product will impact its method and efficacy of UV attenuation: smaller particles are more cosmetically appealing and scatter a smaller proportion of UV.
Oxybenzone
INCI: Benzophenone-3
A universally disliked sunscreen ingredient which is basically only used in the United States, which doesn’t currently allow any second-generation filters to be used in sunscreens. It is a necessary part of sun protection in the US, as the lack of second generation filters on the FDA Sunscreen Monograph force Oxybenzone to play the role of the workhorse UVB filter. It is an efficient blocker of UVB and UVAII, but it penetrates the skin pretty easily.
Octinoxate
INCI: Ethylhexyl Methoxycinnamate
A liquid UVB filter. It can degrade into irritating components with UV exposure, an effect which can be reduced if it is properly encapsulated. It performs better in formulas when combined with Zinc Oxide. Octinoxate has been shown to penetrate the skin, leading to systemic absorption. The human health consequences of this research are unknown.
Octocrylene
A liquid UVB filter. While not enormously potent, it is frequently used in sunscreens because it can help to stabilize the UVA protection offered by Avobenzone. It is a potential contact allergen, and thus isn’t recommended for use on children under 3 years of age.
Octisalate
Octyl Salicylate
INCI: Ethylhexyl Salicylate
Octisalate is a relatively weak UVB filter. While it has not been shown to produce free radicals, it can lead to photoallergy. It has potential to penetrate into the dermis if dissolved in the wrong solvent(s).
Homosalate
Homomenthyl Salicylate
Like all salicylates, Homosalate is a weak UVB absorber, which is why it is often included in formulas at a concentration of >10%. It isn’t very photostable. In lab studies, it has been linked to estrogenic activity, but the human health consequences of this are unknown.
Ensulizole
INCI: Phenylbenzimidazole Sulfonic Acid
Ensulizole is a UVB filter which is soluble in water. On its own, it is not a logical filter in water-resistant sunscreens, but it can be used in products with a light texture. It offers relatively good photostability. As with many first-generation synthetic sunscreen filters, it is pretty small, and could potentially penetrate the skin barrier (although its water-solubility could challenge its journey through the dermal layers).
Amiloxate
INCI: Isoamyl p-Methoxycinnamate
Amiloxate is a UVB filter. Like Octinoxate, it is a cinnamate, and has been known to trigger allergic responses in those who have similar issues with Octinoxate. There is limited additional research on the molecule’s systemic penetration and propensity to lead to negative health outcomes in humans.
Polysilicone-15
Polysilicone-15 is a somewhat efficient UVB absorber. It is a gigantic molecule which is highly unlikely to penetrate the skin.
Iscotrizinol
Uvasorb HEB
INCI: Diethylhexyl Butamido Triazone
Iscotrizinol is an efficient UVB filter. It is a large molecule which is unlikely to penetrate the skin barrier efficiently. It is notable for its strong photostability.
Enzacamene
INCI: 4-Methylbenzylidene Camphor
Enzacamene is a UVB filter.
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Further Reading :
UV FILTERS BY COUNTRY
64 Fed Reg 27687 (May 21, 1999). Retrieved from https://www.govinfo.gov/content/pkg/FR-1999-05-21/pdf/99-12853.pdf#page=1
European Parliament and of the Council (2019). Regulation (EC) No 1223/2009 Annex VI. Retrieved from https://ec.europa.eu/growth/tools-databases/cosing/pdf/COSING_Annex%20VI_v2.pdf
Ministry of Health and Welfare Notification No.331 of 2000. Standards for Cosmetics. Retrieved from https://www.mhlw.go.jp/english/dl/cosmetics.pdf
Australian Government Department of Health (2016). Australian Regulatory Guidelines for Sunscreens. Retrieved from https://www.tga.gov.au/sites/default/files/sunscreens-args.pdf
Health Canada. (2018). Primary Sunscreen Monograph. Retrieved from http://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq.do?atid=sunscreen-ecransolaire
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References :
Osterwalder, U., & Herzog, B. (2009). Chemistry and Properties of Organic and Inorganic UV Filters. In Editor H. W. Lim & Z. D. Draelos (Eds.), Clinical Guide to Sunscreens and Photoprotection (pp. 33). New York, NY: Informa Healthcare USA, Inc
Wang, J. and Ganley, C. J. (2019), Safety Threshold Considerations for Sunscreen Systemic Exposure: A Simulation Study. Clin. Pharmacol. Ther., 105: 161-167. doi:10.1002/cpt.1178
Relevance of UV filter/sunscreen product photostability to human safety. J. Frank Nash Paul R. Tanner First published: 17 January 2014 https://www.ncbi.nlm.nih.gov/pubmed/24433498
Dermatological and environmental toxicological impact of the sunscreen ingredient oxybenzone/benzophenone‐3. Joseph C DiNardo MS Craig A Downs PhD. First published: 31 October 2017 https://www.ncbi.nlm.nih.gov/pubmed/29086472
Incorporation in Lipid Microparticles of the UVA Filter, Butyl Methoxydibenzoylmethane Combined with the UVB Filter, Octocrylene: Effect on Photostability
AAPS PharmSciTech, 2009, Volume 10, Number 2, Page 384. Santo Scalia, Matteo Mezzena
Kerry M. Hanson, Enrico Gratton, Christopher J. Bardeen, Sunscreen enhancement of UV-induced reactive oxygen species in the skin, Free Radical Biology and Medicine, Volume 41, Issue 8, 2006, Pages 1205-1212, ISSN 0891-5849
Avenel-Audran M, Dutartre H, Goossens A, et al. Octocrylene, an Emerging Photoallergen. Arch Dermatol. 2010;146(7):753–757. doi:10.1001/archdermatol.2010.132
