OXYBENZONE, OCTYL METHOXYCINNAMATE UVA ABSORPTION ABILITIES
This article was originally published in The Tan Sheet
OXYBENZONE, OCTYL METHOXYCINNAMATE UVA ABSORPTION ABILITIES are "incorrectly" listed in the sunscreen tentative final monograph, the Cosmetic, Toiletry and Fragrance Association maintained in Nov. 8 comments to FDA. CTFA stated that "although we understand that FDA ultimately may require UVA protection to be substantiated by means of a finished product testing procedure (the methodology for which has not been determined), we are of the opinion that the TFM's conclusions with respect to solution absorbance are incorrect as they relate to two ingredients -- oxybenzone and octyl methoxycinnamate. The former is a UVA absorber but the latter is not." Citing data generated by three independent labs comparing the absorption capabilities of oxybenzone against dioxybenzone, sulisbenzone and menthyl anthranilate, CTFA pointed out that "oxybenzone does, in fact, absorb UVA radiation up to and beyond 360 nm in a manner equivalent to or greater than the other UVA absorbers. Therefore, FDA's contrary conclusion . . . is incorrect." The association said that the studies "indicate that oxybenzone does block UVA radiation from 320 nm up to and past 360 nm as do the other UVA absorbers when measured under equivalent conditions." The TFM "erroneously listed octyl methoxycinnamate as a UVA absorber," CTFA stated. Based on spectral absorbance data, the ingredient "does not absorb up to and including 360 nm. Therefore, it should not be listed as a UVA absorber." CTFA also addressed UVA testing methods included in the TFM. The association noted that while it does not advocate the adoption of any particular testing methodology, "we do urge that the agency not adopt the method utilizing 8-methoxypsoralen (8-MOP) as a phototoxic agent." CTFA pointed out that "although the 8-MOP method will yield an indication of the presence or absence of UVA protectiveness in a sunscreen product, the magnitude of the protection factor has little relevance to normal, unsensitized individuals using sunscreen products in natural sunlight (as FDA has already acknowledged). Thus, the 8-MOP test does not provide a reliable measurement of UVA protection." The safety of 8-MOP for use with repeated exposures was also questioned by CTFA. "While 8-MOP has been utilized under direct physician supervision for almost two decades as a photochemotherapy agent (PUVA) in treatment of psoriasis, mycosis fungoides, and vitiligo, it is now becoming apparent that repeated exposure to 8-MOP with UVA radiation increases the risk of skin cancer formation in PUVA patients." In addition, CTFA said that sensitization to 8-MOP "exaggerates the biological response and presents a real risk of causing severe (ulcerative) acute reactions." Further, the association stated, sensitization of test panelists "puts them at risk for phototoxic reactions for many hours after exposure."
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