Headlines about the 4th annual sunscreen study by the Environmental Working Group focus on the fact that the group recommends only 39 or eight percent of 500 sunscreens.

As stated by the EWG, the primary reasons for the low number of recommendations include:

  • A surge in exaggerated SPF claims; and,
  • Recent developments in the understanding of possible hazards associated with some sunscreen ingredients.

Let’s look first at what the EWG calls exaggerated SPF claims.

Sun Protection Factor

Sun Protection Factor or SPF is an attempt to measure of UVB protection.  And, in theory, the higher the number, the greater the protection. SPF is NOT intended to be a measurement of how long you can stay in the sun and be protected.

The problem with SPF is that while SPF does measure UVB protection, the differences between the degree of protection offered by higher SPFs is not as great as suggested by the actual numbers.  For example, SPF of 15 filters out about 93 percent of the UVB rays while SPF 30 filters about 97 percent of UVB rays. So the UVB protection is not doubled as suggested by the SPF rating. The difference is only four percent. Similarly, SPF 50 blocks 98 percent of UVB, one percent more protection than  SPF 30. And, SPF of 100 blocks 99 percent of UVB, providing one percent more protection than SPF 50.

A second, and in our opinion equally troublesome aspect of SPF as it relates to consumer expectations, is that while experts caution against using SPF as the basis for determining how much time you can spend in the sun, time without burning is the basis for deriving SPF.

To arrive at SPF, the manufacturer gathers human volunteers who are susceptible to sunburns (Skin Types I, II and III on the Fitzpatrick phototyping scale). Scientists then irradiate a small patch of skin and record the UV dose required to produce mild redness.  The test is then repeated using sunscreen to protect the skin. The SPF is calculated by comparing the amount of time needed to produce a sunburn on sunscreen-protected skin to the amount of time needed to cause a sunburn on unprotected skin.

This means that if a person normally turns red after ten minutes in the sun and uses a sunscreen with an SPF of 2, he or she could stay in the sun for 20 minutes. An SPF of 15 would allow that person to multiply his or her burning time by 15 or 150 minutes. So, using this example, an SPF of 85 would in theory allow the person to stay in the sun for 850 minutes or over 14 hours.

But theory doesn’t take into account real world conditions of swimming, perspiring, rubbing off or sunscreen degradation.  This is why experts recommend reapplying sunscreen at least every two hours regardless of the SPF of the sunscreen used.

Moreover, SPF as currently calculated doesn’t take into account UVA exposure.  UVA doesn’t burn the skin, but penetrates through the epidermis to the dermis, damaging connective tissue and increasing the risk of skin cancer.

EWG Study Findings

Our reading of the EWG’s fourth annual sunscreen report suggests that the group is alarmed about consumer expectations generated by very high SPF ratings, including ratings of 70, 85 and 100  SPF.

According to the EWG:

Products with high SPF ratings sell a false sense of security because most people using them stay out in the sun longer, still get burned (which increases risk of skin cancer) and subject their skin to large amounts of UVA radiation, the type of sunlight that does not burn but is believed responsible for considerable skin damage and cancer. High SPF products, which protect against sunburn, often provide very little protection against UVA radiation.

The EWG points to draft regulations published by the Food and Drug Administration (FDA) in 2007 that would prohibit companies from labeling sunscreen with an SPF factor higher than 50.  The EWG quotes the agency as writing that higher values would be “inherently misleading.”

But they are not intentionally misleading. And this is an important distinction.

As the EWG and many others have pointed out, the FDA first announced its intent to publish standards for sunscreens in 1978, more than 30 years ago. In the absence of such standards, the industry is reacting to consumer demand by supplying products with ever higher SPFs.   And, it must be noted that these products undergo rigorous pre-market approval including scientific assessments of safety and efficacy.

Nevertheless, the plethora of products with various SPFs have resulted in  consumer confusion and even anger over the amount and degree of sun protection provided by individual products.


The FDA has indicated it will release its standards for sunscreens in October of this year. After more than 30 years, it’s more than time for the FDA to live up to its decades-old commitment to provide these standards.

Some have criticized the  the 2010 Sunscreen Study by the Environmental Working Group in relatively harsh language.  Frankly, there is some basis for such criticism, but it misses the point.

More productively, the American Academy of Dermatology and others have issued statements urging consumers to continue using sunscreens and providing advice about minimum SPF recommendations, and the amounts and times to apply sunscreen.

With respect to the specific issue of current SPF labeling, our bottom line is that in the decades-long absence of standards, the Environmental Working Group is filling a watch dog role by warning consumers to be careful of   unrealistic expectations about the amount of time they can spend safely in the sun using a sunscreen with a high SPF.

In the absence of easy-to-understand uniform standards, the publicity generated by the report should cause consumers to take a hard look at SPF to understand its value and its limitations.

In the absence of uniform standards, our hope is that concerned consumers will turn to the experts, the AAD, the Dermatology Nurses Association, the National Council on Skin Cancer Prevention, the Melanoma Foundation of New England, the Children’s Melanoma Prevention Foundation and others for guidance on using sunscreen.

In that respect, the study has value.

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