Suncreen SPF Myths Debunked

Photo courtesy of

Photo courtesy of


The Environmental Working Group is a non-profit organization that works to provide consumers with the truth about what’s in our products and the effects product ingredients can have on our health. They cover a wide range of household items, including skin care, food, and cleaning supplies. Just in time for summer is their guide to what to look for, and watch out for, in sunscreens.

I’ve included here a few excerpts from their webpage on sunscreens. To see the rest, go to You can also make a small donation to receive a guide on the best sunscreen products. They do exhaustive research on hundreds of products, including brand name items.

From their website:

Theoretically, applying sunscreen with a sun protection factor – SPF – of 100 would allow beachgoers to bare their skin 100 times longer before suffering a sunburn. Someone who would normally redden after 30 minutes in the midday sun could stay out for 50 hours.

But for high-SPF sunscreens, theory and reality are two different things. Many studies have found that people are misled by the claims on high SPF sunscreen bottles. They are more likely to use high SPF products improperly and as a result may expose themselves to more harmful ultraviolet radiation than people relying on products with lower SPF. The reason: People trust these products too much.

The article goes on to explain why any SPF above 50 is suspect. Here’s a bit of that:

Marginally better sunburn protection – Sunbathers often assume that they get twice as much protection from SPF 100 sunscreen as from SPF 50. In reality, the extra protection is negligible. Properly applied SPF 50 sunscreen blocks 98 percent of sunburn rays; SPF 100 blocks 99 percent. When used correctly, sunscreen with SPF values in the range of 30 to 50 will offer strong sunburn protection, even for people most sensitive to sunburn.

High SPF products may not really be high SPF– When Procter & Gamble tested a competitor’s SPF 100 product at five different labs the results varied between SPF 37 and SPF 75. The company determined that a very small differences in the testing conditions can have a dramatic influence on the calculated SPF. In this case a 1.7 percent change in the light transmission yields a SPF measurement of 37 instead of 100. Small difference in application thickness could have a similar effect. Because of the way SPF values are calculated these errors would be most dramatic for high SPF products. In a letter to the FDA P&G warned that the intense UV light used in laboratory SPF tests are different than the conditions experienced in the real world, and of “dubious value”. They concluded that SPF values should be capped at 50+ because the current system is “at best, misleading to consumers” and “may inappropriately influence their purchase decision” (P&G 2011).

Go to for the full article.




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