PracticalDermatology

It seems impossible to open your browser these days without seeing something about the dangers of personal care products, such as cosmetics and sunscreens. As dermatologists, we know that long-term use of these skincare products suggests that they are safe, but recent studies have sounded alarms, making consumers and our patients concerned about their safety. To best address patient concerns, it is important to understand the studies, their methodology, and the implications of their findings.

There are several issues of concern when it comes to sunscreen safety. Ingredients like oxybenzone have been scrutinized and deemed unsafe by various watchdog groups. Oxybenzone is an endocrine disruptor and may influence hormonal production. This is of particular concern in children. It is also a sensitizer and potential allergen. In addition, oxybenzone is believed to have a negative impact on ocean life, and it has been banned for use in Hawaii.

More recently, data on sunscreen absorption published by the FDA has caused further concern among consumers. The first study, published in JAMA in 2019, included 24 participants who used either a spray, lotion, or cream sunscreen containing a combination of avobenzone, oxybenzone, octocrylene, and ecamsule. A standardized dose of the sunscreen (2mg/cm²) was applied to 75 percent of the body surface four times a day for four days. Under maximal use, the blood levels of all four UV filters exceeded the FDA’s safety threshold (0.5ng/ml) by the end of day 1 and remained elevated until day 7 for three of the four ingredients. After criticism that this pilot study was not reflective of real use application, the FDA conducted a follow up study published in JAMA in 2020. In this study, 48 subjects used one of four sunscreen formulations including a lotion and sprays, that contained various combinations of six UV filters including avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate. The subjects applied a standardized dose of sunscreen once on day 1, followed by four applications per day on days 2 through 4. After day 1 and a single application of sunscreen, blood levels of all six chemicals were over 0.5ng/ml, and the levels for some ingredients remained elevated for as long as 21 days.

Although the FDA has continued to endorse the use of sunscreens as a matter of public safety, they are calling on manufacturers to perform further safety studies on 12 ingredients before they can continue to deem these ingredients GRASE (generally recognized as safe and effective). At this point, we can reassure our patients that there is no evidence that absorption is associated with medical adverse effects. The FDA continues to consider zinc oxide and titanium dioxide as GRASE ingredients.

Other concerns about sunscreen include the recent findings by an independent laboratory that benzene, a known carcinogen associated with hematologic cancers, was found in 78 different sunscreens and after-sun products. This was an unexpected finding, with manufacturers repeatedly stating that benzene is not a component in any sunscreen formulation. After testing found low levels of benzene in five spray sunscreens, Johnson & Johnson issued a voluntary recall of these formulations. There is still much to learn about benzene as a contaminant of sunscreens, so for now it is best to advise patients to stick to those products that tested negative for benzene.

Cosmetics have not escaped unscathed. Clean beauty advocates search for products free of parabens, phthalates, formaldehyde releasers, sulfates, hydroxytoluene, fragrance, propylene glycol, and even petrolatum. The Environmental Working Group’s (EWG) skin deep database scores thousands of products based on the alleged toxicity of their ingredients. Each product is scored based on cancer potential, reproductive toxicity, and allergenicity. As dermatologists, we know that ingredients like petrolatum have great therapeutic value and that endocrine disrupters are ubiquitous and include naturals like lavender and tea tree oil. Thus, it is difficult to advise patients on selecting cosmetics when they are getting so many mixed messages.

The most recent potential threat from cosmetics is related to a study published in Journal of Environmental Science and Technology that found some liquid lipsticks, waterproof mascara, and foundations have high levels of fluorine, indicating the presence of polyfluoroalkyl substances (PFAS). PFAS are a class of chemicals used to make cosmetics more spreadable and durable but have known health effects, including impaired immune and endocrine functions, as well as an increased risk of diabetes, obesity, and certain cancers. In June 2021, Congress introduced the “No PFAS in Cosmetics Act.” Clearly the safety of cosmetics is a top priority for consumers and legislators alike.

Drs. Farris and Lain are founding directors of the Science of Skincare Summit 2021, to be held November 6, 2021 at JW Marriott Essex House in New York. Registration and information are available at scienceofskincaresummit.com.