It's close to the end of summer now, but sunscreens are on my mind because of the recent statement from Consumers Union.
There are two primary categories of sunscreens:
Chemical sunscreens such as oxybenzone, octisalate, and others; and
Mineral-based sunscreens such as titanium and zinc oxides.
Many sunscreen formulations include both of these categories with multiple effective - or supposedly effective - ingredients. Supposedly? Well, according to the Environmental Working Group, "40% of products on the market contain ingredients that may be unstable alone or in combination" when exposed to sunlight.
So, given that the effectiveness of chemical sunscreens is not proven, it seems a given that the particle-based ones are the route to choose. But not so fast; those particles have been engineered to be smaller - nanoscale (1 nanometer = one millionth of a millimeter) in fact - and there is concern that they could be absorbed through the body's largest organ - the skin - and taken into the lungs; Consumers Union also expressed concern about the impact on the ecosystem.
Doesn't the FDA regulate such products?
From The Washington Post: "The FDA regulates sunscreens as nonprescription drugs and does not require extra safety tests specific for nanoparticles. The agency has little authority over cosmetics. " (take note: other topical products are also likely to have questionable safety)
The EWG says,"FDA has spent the past 30 years drafting sunscreen standards (FDA 2007a), which it urges manufacturers to follow voluntarily. FDA issued its latest draft standards in August 2007, which include a proposal for first-ever UVA standards, but still has failed to finalize the standards to make them mandatory. In lieu of enforceable standards, each sunscreen manufacturer decides on test methods, marketing claims, and the level of protection they are willing and able to provide consumers." (emphasis added)
This should be no surprise to people who are familiar with bisphenol-A or parabens, both of which only began to disappear from products following objections from activist groups and restrictions by other countries.
The EWG reports that, this year, 2 of 5 sunscreens on the market are effective (some of these contain nanoparticles) - in other words, 60% are not effective.
Review of Scientific Literature on Nanoparticles, published by the Australian Government
EWG's summary on sunscreens - read study data, view the database that lists ingredients and estimates safety and effectiveness.