As spring fades and summer begins, sun protection discussions arise. Despite countless studies, there still exist many misconceptions about sunscreen. This issue is quite prevalent, as, according to the Skin Cancer Foundation, skin cancer is the most common type of cancer in the world. In addition, according to the Mayo Clinic, “by age 70, one in five people in the U.S. will develop skin cancer.”
One major myth about sunscreen is that it is only necessary to wear it on sunny days. The reality is that if the sun is out, you are exposing yourself to UV rays. Even if you are not in direct sunlight, things like sand and even snow can reflect the rays onto your skin. According to the Mayo Clinic, “even on cloudy days, up to 90 percent of the sun’s rays still can penetrate your skin.” It is important to wear sunscreen everyday, not only on days you will be out in the sun.
Another misconception is that higher SPF ratings provide significantly better skin protection. This is also untrue, as a sunscreen rated 30 SPF protects up to 97 percent of rays, while a sunscreen rated 100 SPF, according to the Mayo Clinic, protects just one to two percent more. Nonetheless, this higher SPF can still make a difference, being that most people do not apply enough sunscreen. In those cases, a higher SPF sunscreen may be beneficial to get those extra percentages of protection. In any case, follow the FDA recommendation of at least one ounce of sunscreen for the face and body.
A major misconception that even scientific sources get wrong is the difference between physical sunscreens and chemical sunscreens. To start, a physical sunscreen is one that utilizes either zinc oxide or titanium dioxide as the active ingredient. A chemical sunscreen, on the other hand, may use oxybenzone, octinoxate, homosalate or other similarly-acting compounds. Chemical sunscreens work by absorbing the energy from UV light rays and “convert[ing] it into more harmless forms of energy, mostly heat,” explained Michelle Wong, a writer and YouTuber with a PhD in chemistry. Physical sunscreens work in the same way, but in addition to absorbing the energy, a very small amount of the UV is scattered. The misconception, though, is that physical sunscreens only work by scattering UV. Wong points out on her website that the myth likely originated from the FDA’s 1978 monograph, where it was written: “instead of absorbing light, [physical sunscreens] scatter and reflect such light.” It was not taken out until 1999, which Wong points out as a possible reason for the misconception being so widespread.
Chemical sunscreens have also had their fair share of myths. One myth that is still prevalent is that certain active compounds in sunscreens disrupt hormones. Even the Mayo Clinic has published this misconception. In 2023, they wrote about one of these chemicals, oxybenzone, stating, “if possible, avoid sunscreens with oxybenzone because this chemical may disrupt hormones and cause allergic reactions.” This misconception stems from studies done on rats, which do not necessarily apply to humans. Assistant professor of dermatology at Harvard Medical School, Jennifer Lin, explains this in a Harvard Health Publishing article. She stated in the interview, “There has been no conclusive evidence that oxybenzone is harmful to humans. Organizations that have raised concerns about oxybenzone typically cite studies done in rats, where the rats were actually fed oxybenzone. It would take an individual 277 years of sunscreen use to achieve the equivalent systemic dose that produced effects in these rat studies […]. Oxybenzone is also known to cause allergic reactions in some people, although this is not common.”
There are far more misconceptions about sunscreen, and these are just some of the main ones. For further information on sunscreen safety and recommendations, one website that contains exceptional information is Michelle Wong’s “Lab Muffin Beauty Science”, where she goes into even further detail on exactly how sunscreen works at the molecular level. The best source for reliable sunscreen information is the FDA, which can be found at fda.gov.
