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Don’t get burned with a high SPF sunscreen

Monday, July 6, 2015


As a research intern at EWG, I’ve investigated sunscreens to learn more about how they work and the claims that companies make.

I wondered why I’d been told to put sunscreen on a sunburn, even after I came inside. The answer isn’t soothing. Anti-inflammatory ingredients in sunscreen  suppress redness, pain and inflammation, even after skin damage. In other words, the sunscreen makes burned skin feel better temporarily – but it’s still burned.

Out in the sun, these anti-inflammatory ingredients inflate a product’s SPF but they don’t necessarily block more UV light. That means people stay outside longer than they should and damage their skin without realizing it.

Here’s another shocker.  The difference in the amount of protection offered by SPF 50 and SPF 100 products is rarely as significant as consumers expect. An SPF 50 sunscreen should block about 98 percent of sunburn rays (primarily UVB rays) and an SPF 100 product should block 99 percent. The key word is “should,” since, in the real world, products with high SPFs on the label rarely achieve the protection they claim. For starters, people seldom apply sunscreen in a layer thick enough to reach that value.

Research has shown that high SPFs can encourage risky behaviors. A French study found that people might be lulled into a false sense of security by high-SPF products and, as a result, spend more time in the sun without reapplying sunscreen.

At EWG, we’ve noticed that an SPF 15 and an SPF 70 sunscreen might have the exact same combination of active ingredients at the same percent. So how do they offer such a different degree of protection from sunburn? We don’t know for sure—possibly with anti-inflammatory ingredients.

Sunburns mean that UVB rays have inflicted DNA damage. Anti-inflammatory ingredients can suppress a natural sunburn response for up to 6 hours.  

Many sunscreens contain antioxidants that possess anti-inflammatory properties. Among them: vitamin E (often listed as tocopherol), vitamin C (ascorbic acid) or other antioxidant-rich extracts derived from fruits, nuts, roots, leaves or other parts of plants. The common sunscreen ingredients oxybenzone and homosalate suppress inflammation.

What should you do? Remember that sunscreens can provide only partial protection against the harmful effects of the sun, including skin cancer, premature skin aging and immune suppression.

Reduce sun damage by picking a sunscreen with an SPF between 15 and 50 and by applying a thick coating on your skin. Sun damage can occur even if you don’t get burned. Reapply sunscreen at least every two hours.  

Consult EWG’s sunscreen guide to choose a safe, effective sunscreen. Also be sure to check out our new sunscreen label decoder.



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