Re: In 19: Note that new P,P&P paper does not agree with your...From: Dianne Godar DEG@CDRH.FDA.GOV CommentsI can Fax you a copy of that paper (email me if you want it). The authors are Stender and Lock-Andersen at the Dept of Dermatol, Bispebjerg Hospital, U. of Copenhagen, Denmark. They basically found that people do not use the sunscreens as recommended (who reads that anyway?), which they complain is not pratical because one would have to apply it and let it absorb into the skin about four times before going outdoors (each coat is about 0.5 mg/cm2). They strongly suggest that testing for SPF be changed to what people actually do rather than trying to change people (very practical). What is actually used by people is one coat at 0.5 mg/cm2 rather than four coats at 2 mg/cm2. Their Fig 1 shows that if testing is done on 2 mg/cm2 a BIG difference between the protection factors is observed from 2 to 50 SPF, but if appplied as people use them at 0.5 mg/cm2 then there is basically no significant difference between SPF 2 and 50 (they are all about SPF2-4; though I bet the cost is different)! Anyway, now I'm glad I only used SPF 4 (waterproof). Why coat chemicals on your body when they are apparently of no extra benefit, and we don't have any idea what the photoproducts can do! Has anyone done photoproduct carcinogenesis studies? Increase melanoma? And overall risk of skin cancer? I know we have all wondered why CHS is only 50% increased by sunscreen protection compared to the UV exposed animals. What happened to the other 50%? Maybe the investigators, or the mice, didn't use the sunscreens "AS RECOMMENDED"!!! |