Jacklyn’s just concerned: I was told that products that are combination sunscreens and insect repellents may not be safe. Is this true? The Left Brain cautiously responds:
Yes, Jacklyn, there is reason for concern over sunscreen/repellents. According to an Associated Press report, there have been a few small scale studies (done on animals and human skin cells, by the way) that indicate mixing sunscreen actives with DEET (the insect repellent active ingredient) might not only increase skin penetration of DEET but also reduce efficacy of the sunscreen.
The FDA put out a notice asking for comments to determine if this is a problem or not. And the Cosmetic, Toiletry and Fragrance Association says that the small studies that showed the problem are flawed. So what happens next? More research.
Certainly this is an important issue that merits further research, but there may be a more immediate reason for concern. Think about how these products are designed to be used: Sunscreens need to be repeatedly applied, in fairly large quantities, to keep your skin covered. But insect repellents are only intended to be applied occasionally (to prevent over exposure.)
So while a combination sunscreen/insect repellant sounds like a great idea, they kind of cancel each other out in a weird way – if you apply enough product to give good sun protection then you might be overdosing on the insect repellent. But if you lower the dose of the repellant, you don’t get enough sunscreen.
Thank you very much, but I’ll just carry two separate products in my beach bag.