USAN/INCI Spectral range Maximum concentration Function Remarks Regulatory status Reference Ecamsule/terephthalylidene dicamphor sulfonic acid (TDSA) UVA1, UVA2 3% Absorbs UV rays and then releases the UV rays as thermal energy no skin penetration Photostable water-soluble does not protect against the entire UV spectrum, so has to be combined with other fi lters for good protection FDA approved patent held by L’Oréal and its brands (48,49) Ecamsule/ trisiloxane UVA2 3% Absorbs UV rays no skin penetration Photostable, oil-soluble, used synergistically with terephthalydiene dicamphor sulfonic acid Not yet approved by the FDA (49) Octinoxate/ methoxycinnamate (EHMC ) Octyl methoxy-cinnamate (OMC) UVB 7.5% Absorbs UVB rays Water-insoluble, not photostable as most degrades over time when exposed to sunlight, can be stabilized by other UV fi lters such as methylene bis-benzotriazolyl tetramethylbutylphenol, there are some safety concerns are involved as absorbed by skin FDA approved (48,49) Octocrylene/Octocrylene (OCR) UVB, UVA2 10% Absorbs UV rays Photostable, helps to stabilize other UV fi lters, oil-soluble, Absorbed by skin FDA approved (48,49) Octisalate/ salicylate (EHS) UVB 5% Absorbs UV rays Undergoes some degradation in sunlight, has emollient and water-resistant properties, Oil-soluble (so less greasy) FDA approved (49) Homosalate/ salicylate (HMS) UVB 15% Absorbs UV rays Undergoes some degradation in sunlight, oil-soluble, excipient of many Coppertone sunscreens FDA approved (49) Octyltriazone/ triazone UVB 5% Absorbs UV rays Water resistant and long lasting Not approved by FDA (49) Table II Continued UV PROTECTION AND EVALUATION OF EFFICACY OF SUNSCREENS 327

USAN/INCI Spectral range Maximum concentration Function Remarks Regulatory status Reference Cinoxate UVB 3% Absorbs UV rays Slightly yellow, Insoluble in water FDA approved, though no longer commonly used (49,50) Aminobenzoic acid UVB 15% Absorbs UVB rays One of the fi rst active ingredients in sunscreen, causes allergies, causes clothing discoloration, increased risk of cellular UV damage Banned from sale in Europe, not used in sunscreens anymore (49,51) Padimate O/Ethylhexyl Dimethyl PABA (EHDP) UVB 8% Absorbs UVB rays Water-insoluble PABA derivative controversially active because after absorbing UVB rays, the active may produce indirect DNA damage used with other chemicals to increase SPF of a product water resistant and does not stain clothing FDA approved, not being supported by the EU and may be delisted (49,52) Ensulizole/ sulfonic acid (PBSA) UVB, UVA2 4% Absorbs UVB rays Does not degrade much in sunlight, but more studies are needed about its stability feels lighter on skin Used in sunscreens with less greasy fi nish FDA approved (49,53) Dioxybenzone UVB, UVA2 3% Absorbs UVB rays and short-wave UVA rays A derivative of benzophenone Insoluble in water, so lends to water proof claims FDA approved (49,54) Oxybenzone/Benzophenone-3 (BP3) UVB, UVA2 6% Provides effective broad spectrum protection from UV radiation, and has been approved for use since 1978 Penetrates the skin and may have some hormone-like activity in the body 56% of sunscreens contain chemical oxybenzone FDA approved Approved for children older than 6 months (49,55) Table II Continued JOURNAL OF COSMETIC SCIENCE 328