Sunscreen products are intended for daily use throughout a person’s lifetime. It is crucial for the companies manufacturing and selling sunscreen ingredients and products to thoroughly test them for potential short-term and long-term health effects. These tests should include toxicity assessments for skin irritation, allergies, skin absorption, and the potential to cause cancer, hormone disruption, as well as harm during reproduction and development.
Concerns about sunscreen ingredients
Inadequate safety data and emerging concerns
In 2019, the federal Food and Drug Administration (FDA), responsible for regulating sunscreen safety, proposed updates to sunscreen regulations. Based on available information, only two ingredients, zinc oxide and titanium dioxide, were classified as safe and effective. However, recent studies have raised new concerns about three other ingredients: homosalate, avobenzone, and oxybenzone.
European commission’s findings
In the past year, the European Commission published preliminary opinions on the safety of three organic UV filters: oxybenzone, homosalate, and octocrylene. The Commission found that the current usage levels of two of these ingredients were not safe and proposed concentration limits. U.S. sunscreen manufacturers, however, are legally allowed to use these chemicals at concentrations exceeding the European Commission’s recommendations.
Active ingredient toxicity
Examining the science on ingredient toxicity
Oxybenzone
Oxybenzone is the most concerning active ingredient in sunscreens based on available scientific research. It is readily absorbed through the skin and has been detected in nearly all Americans. Oxybenzone has been associated with allergic skin reactions, behaves as an endocrine disruptor, and poses potential harm to children.
Octinoxate (Octyl methoxycinnamate)
Octinoxate is an organic UV filter that readily absorbs into the skin and continues to be absorbed even after sunscreen application. Animal studies indicate that it has hormone effects on the metabolic system, including thyroid hormone production. Octinoxate can also cause allergic reactions after exposure to ultraviolet light.
Homosalate
Homosalate is an organic UV filter widely used in U.S. sunscreens. The FDA has proposed that there is insufficient data to evaluate its safety and effectiveness. Research suggests that homosalate can penetrate the skin, disrupt hormones, and produce toxic breakdown byproducts over time.
Octisalate
Octisalate, another organic UV filter, absorbs through the skin at levels exceeding the FDA’s cutoff for systemic exposure. The FDA also states that there is insufficient data to determine whether it can be considered safe and effective. Octisalate has been linked to allergic contact dermatitis.
Octocrylene
Octocrylene absorbs through the skin at levels exceeding the FDA’s cutoff for systemic exposure. It has been associated with high rates of skin allergies and potential harm to coral health. Octocrylene is often contaminated with benzophenone, a known carcinogen.
Avobenzone
Avobenzone is a widely used organic filter providing UVA protection. Breakdown products of avobenzone can cause allergic reactions, and it can disrupt the endocrine system. High levels of avobenzone have been detected in serum samples.
Titanium dioxide and zinc oxide
Mineral sunscreens contain titanium dioxide and zinc oxide, usually in the form of nanoparticles. The FDA has proposed that both titanium dioxide and zinc oxide be classified as safe and effective. Evidence suggests that these particles have limited penetration into the skin, reducing the risk of systemic exposure. However, there are inhalation concerns associated with powdered or spray formulations containing titanium dioxide. Zinc oxide can also pose inhalation risks in spray and powder products.
Other active ingredients
Mexoryl SX, although uncommon in U.S. sunscreens, offers strong UVA protection. The FDA’s analysis indicates insufficient data to classify it as safe and effective. Public research shows no evidence of hormone disruption and a rare incidence of skin allergy.
Aminobenzoic acid (PABA) and trolamine salicylate are active ingredients that are no longer commonly used in U.S. sunscreens. The FDA’s 2019 proposal concluded that the risks of these chemicals outweigh their benefits, classifying them as unsafe.
Inactive ingredients and safety concerns
In addition to active ingredients, it is important to examine the so-called inactive ingredients in sunscreens, which comprise a significant portion of the product. These ingredients can account for 50 to 70 percent of a sunscreen formulation. Further investigation by the FDA is necessary to ensure that none of these ingredients cause skin damage or other health harms.
Conclusion
The safety of sunscreen ingredients is a critical concern, considering their lifelong use and potential health effects. While mineral sunscreens containing titanium dioxide and zinc oxide generally rate better than chemical sunscreens, it is crucial for manufacturers to use coated forms of these minerals to minimize photoactivity. The FDA should prioritize thorough testing and evaluation of all sunscreen ingredients to ensure their safety and protect consumers from potential risks.