Terje Christensen suggests that octyl methoxycinnamate (OMC), a filter frequently used in commercial sunscreens, could be toxic (7 October, p 13). We have studied OMC on a number of occasions, using fresh human skin removed during cosmetic operations. In none of our studies did applying OMC to the skin have any impact on the viability of the cells. OMC was able to protect the skin's immune system cells from the immunosuppressive effects of ultraviolet light.
Our studies show that OMC is not toxic to human skin cells when it is applied directly to the skin, and that it is effective at preventing sunburn and ultraviolet immunosuppression.
To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.