Sunscreens have been commercially available in the United States since the late 1960’s. We now use sunscreens with high sun protection factor (SPF) but this apparently has not been enough since the incidence of skin cancer has continued to rise. This has led at least one cancer center to postulate that the use of sunscreens may be partially responsible for the increase in skin cancer. What are the possible explanations for this apparent controversy?
Is There a Problem with the Sun Protection Factor (SPF)?
Most people understand the concept that the higher the sun protection factor (SPF) then the stronger the sunscreen. However, few people truly understand what it means. If you get sunburned within five minutes of being in the sun without sunscreen, then using a sunscreen with an SPF of 15 indicates that you could stay in the sun for 15 times five minutes or 75 minutes before getting the same sunburn. The problem is that the SPF only applies to the amount of protection against the ultraviolet B (UVB) rays of the sun which cause sunburn, and does not indicate how much ultraviolet A (UVA) protection there is. Also, with swimming or sweating, the sunscreen washes off and after a certain amount of time, is no longer providing the advertised SPF protection. UVA has been shown to be the ray of the sun that promotes skin cancer. It is hypothesized that we are using sunscreen that prevents us from being sunburned, and therefore we are staying in the sun longer than ever before. This allows us to get more UVA than we got before the advent of sunscreens. In other words, sunscreens have given us a false sense of security that we are completely protecting ourselves from the sun when we actually are not.
A Brief History
Sources vary on who developed the first sunscreen. It is often credited to the founder of the L’Oreal cosmetic company, Eugene Schueller in the 1930’s. However, other sources credit Austrian scientist Franz Greiter for developing a sunscreen called Glacier Cream in the mid 1940’s after being sunburned while mountain climbing.
What Has Been Done to Improve Our Level of Protection?
The federal drug administration (FDA) has recognized that there is potential for confusion regarding the labeling of sunscreens. Therefore, they have instituted new requirements for sunscreen labeling that helps us to choose a sunscreen that provides adequate protection and tells us for how long that protection lasts. Now, in addition to the SPF, there should be the words “broad spectrum” on the label which indicates that there is adequate UVA protection as well. Without this wording, the sunscreen should have a warning label indicating that use of the product may lead to the development of skin cancer. In addition, the sunscreen label should indicate how long the sunscreen is sweat resistant and water resistant. If the label indicates that the sunscreen is sweat or water resistant for 40 minutes, then it needs to be re-applied at that time in order to maintain the advertised SPF. There is no “sweat proof” or “water proof” sunscreen.
Using sunscreen is imperative for us to enjoy our time in the sun without developing skin cancer. Sunscreen use does not cause skin cancer, but not understanding the labeling can lead to a false sense of security and allow us to get more of the cancer causing UVA rays. Understanding the labeling, using the correct amount of sunscreen and reapplying it when the sunscreen begins to wear out is important to ensure our safety.