Beyond these concerns with organic and inorganic UV filters, there are several other claims regarding sunscreen safety that have stirred up controversy, including the side-effect profile of retinyl palmitate, vitamin D deficiency, phototoxicity, environmental effects, futility of sun protection factor levels greater than 50, and increased health risks in children. Although some studies report mixed results, the majority of scientific investigations have addressed and refuted several of these claims, again confirming the relative safety of sunscreen use. It is beyond the scope of this article to further discuss these topics specifically. However, it is worth mentioning that consumer studies report that the actual use of sunscreens is 0.5 mg/cm2 or less compared to the ideal application of 2 mg/cm2, thereby confounding many of the claims made about sunscreen use, such as vitamin D deficiency.45 Sunscreens often contain a combination of several UV filters. To date, only a few existing studies have shown that mixtures of the photoprotective agents discussed might interact and exhibit toxic activity when combined, even when there is no observed adverse toxic effect when used individually in products.46-48
The current FDA ruling on sunscreen labeling does not require manufacturers to state if inorganic UV filters have been formulated into nanoparticles; however, manufacturers are now required to include a statement on all sunscreen labels warning consumers to avoid using sunscreen on damaged or broken skin49 in an effort to prevent the active ingredients from getting under the skin, potentially causing inflammation and/or health risks, because available data do not provide conclusive evidence on increased penetration of open skin.50 Additional information regarding the 2011 FDA sunscreen ruling can be found in a prior Cutis Resident Corner column.51
Final Thoughts
As health care providers, we should take advantage of opportunities to educate our patients about other sun safety practices, such as avoiding excessive sun exposure during peak hours (10 am to 2 pm), seeking shade, and wearing photoprotective clothing (eg, wide-brimmed hats, sunglasses).
The research is quite clear: Using broadband sunscreens that absorb and/or block UV radiation results in reduced damage to the skin’s DNA, a fact that should be considered when taking into account the risks and benefits of sunscreen use.2,3 Although sunscreen use is highly recommended in addition to the other sun protection methods, it is ultimately the patient’s choice. If a patient is still concerned about the active ingredients of UV filters, even given the high probability of safety, there are products available on the market that do not include organic filters or nanoparticles. Given the established benefits of UV protection, the use of sunscreens remain one of the most important photoprotective methods, and with increased usage by the public, continuous monitoring of the overall safety and benefit profile of future products is prudent.
