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SPF Test Debate Sizzles
By: Nancy Jeffries
Posted: October 10, 2008, from the February 2006 issue of GCI Magazine.
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“There are organic protectors that, in all cases, destroy free radicals, which are damaging to the cells—(even) more so (to) the Langerhans cells in the skin,” said Kuster. “The inorganic, mineral-derived protection acts more as a reflector of sun rays, and, due to micronization, has become a vital tool for the formulator. Using organic and inorganic protection combined gives you the ultimate sun protection.” Acknowledging the challenge to give the right number for SPF products due to various skin types, geography and mountain or ocean level effects, Kuster suggested classifications such as “Low SPF” (up to 10), “Medium SPF” (11–20) “High SPF” (21–30) and “Extra High” (30 and above) to “take a lot of misinformation out of the SPF game.”
Robert Sayre, Ph.D., Rapid Precision Testing Laboratories, cited problems with current sunscreen testing and labeling. “The required standard source only vaguely resembles sunlight. Consequently, the SPF values don’t mean anything in sunlight. The resulting source has too much short wavelength UVB and only half of the UVA in most sunlight. This causes product SPFs to be so unreasonably high as to be meaningless,” Sayre said. “It’s very difficult to get a 15 MED exposure anywhere in a single day, yet products are labeled SPF 30, SPF 45, SPF 65. Most sunscreen ingredients are photounstable, and products fall apart when exposed to sunlight. They don’t seem to work as well in sunlight as in the testing laboratory, and there is no sunlight test for photostability.
“Consequently, high SPFs really don’t mean anything,” Sayre added. “Sunscreen hucksters push high SPFs and UVA protection, yet it’s debatable that any additional UVA protection is needed.” Sayre said that while no one is injured by exposure through window glass, and there are no normal UVA-induced injuries, all experts seem to believe that you must block UVA.Sayre published a paper showing that every sunscreen ingredient tested inhibited the inducible nitric oxide synthase response. This means that some sunscreens act like anti-inflammatory drugs, inhibiting the production of normal sunburn not by blocking UV and preventing injury, but by preventing the response to injury. Further, Sayre suggested too many sunscreen agents are used in too many different products.
David Steinberg, president, Steinberg & Associates, says consumers interpret SPF numbers to mean the amount of time they can stay in the sun and not get burned. A cosmetic chemist will say it’s the ratio of MED with the sunscreen divided by the MED without protection. This means SPF 30 allows you to be exposed to UV radiation for 30 times longer with this product than without sun protection before you get sunburn.
“While these may be true, these are very misleading, and in reality SPF labeling of products is a fraud, as far as I’m concerned,” said Steinberg. “Why? Who knows their MED? It usually is thought to be about 20 minutes in summer sun in the greater New York area. But this varies by different areas, angle of the sun, time of year and more.