Sunscreen a potential health threat?
Sunscreen has been a summer staple for decades but recommended for widespread routine use only since demontrating protection against skin cancer. While it was originally believed that sunscreen was not absorbed, there is now evidence that many sunscreen ingredients can be detected in blood and urine.
What’s more, the FDA in 2019 released its final draft sunscreens monograph, noting that for 12 of 16 common sunscreen ingredients, there is “insufficient health and safety data” to allow the agency’s designation of them as “generally recognized as safe and effective,” or GRASE.
Don’t counsel patients to leave the sunscreen behind this summer but do test your knowledge of the ingredients and their safety with our 5-question quiz.
Question 1. Which of the above ingredients commonly found in sunscreen products carries the FDA designation GRASE?
Answer: A. Titanium dioxide. Titanium dioxide and zinc oxide are the only 2 commonly used sunscreen ingredients that are designated as GRASE by the US FDA. Homosalate and avobenzone are in the category “Insufficient data and significant data gaps” and PABA has been declared “Unsafe for use” by the FDA.
Question 2. Which one of the above common ingredients included in the FDA’s group of compounds with “Insufficient data/significant data gaps” is a potential endocrine disrupter?
Answer: C. Oxybenzone. Oxybenzone is one of the most widely used active ingredients in US commercial sunscreens. In response to calls for investigation into oxybenzone safety and based on accumulated evidence of significant absorption through the skin, the FDA has proposed new studies that will measure transdermal absorption and potential interference with hormone levels, reproduction, and development. Existing tests have detected oxybenzone in human breast milk, amniotic fluid, blood, and urine.
Question 3. True or false? European standards for ultraviolet (UV) protection in sunscreen products are more stringent than US standards.
Answer: A. True. In fact, many US sunscreens are “too weak” to be sold in Europe. Although most US products claim “broad spectrum” protection from UV rays, they block primarily the high-energy UVB light responsible for sunburn, damage to skin DNA, and non-melanoma skin cancers. US products, unlike European sunscreens, offer scant protection from the UVA rays that penetrate more deeply and are associated with immune suppression, formation of free radicals, and greater risk for melanoma.
Question 4. In its 2019 final draft sunscreens monograph, the FDA set the maximum allowable sun protection factor (SPF) to be assigned to US products at which of the above?
Answer: C. SPF 60+. The FDA states there is a, “lack of data showing that sunscreens with SPF values above 60+ provide additional meaningful clinical benefit,” and has noted that values higher than that are “inherently misleading” to the public. The SPF value assigned is based on the concentration of ingredients that filter UV light, but there is no evidence that higher levels are more protective than lower levels. A former WHO scientist who studies how people sunbathe contends that, “high-SPF products spur ‘profound changes in sun behavior…’” People are more likely to use less of a product that promises greater protection and also to spend more time in the sun. (Note: The cap at 60+ means that a manufacturer cannot label a product with a higher SPF value even if it considers the formulation to have a higher value)
Question 5. In 2007, 38 US sunscreen products were marketed with an SPF value >50+. In 2019, to date, what is the number of products labeled as such?
Answer: D. >75. To date, there are 84 sunscreen products sold in the US that claim an SPF value >50+. The FDA is concerned that the “false sense of protection” that may accompany use of a sunscreen labeled with rising SPF values could increase consumer exposure to the deeply penetrating and cancer-causing UVA rays. In US products, an increase in SPF is based on greater concentrations of current UVB-filtering ingredients – however, UVA protection is not increased proportionally. In Europe, the result of voluntary compliance by most producers of sunscreen to current recommendations is a selection of products with UVA protection at least a third as potent as the SPF.
Sources:
1. Proposed Rule: Sunscreen Drug Products for Over-the-Counter Human Use. CFR
2. Environmental Working Group (EWG) guide to sunscreens
3. FDA: Sunscreen Chemicals in Blood Show Need for Safety Testing - Medscape - May 14, 2019. (Interviews with FDA officials Theresa M. Michele, MD, director, Center for Drug Evaluation and Research, division of nonprescription drug products and new drugs office; and David Strauss, MD, director, division of applied regulatory science)
