By Ashlyn Dowd
On May 1, 2018, the Hawaiian legislature signed a bill banning the distribution of sunscreens that contain the chemicals oxybenzone and octinoxate because scientists have found that these chemicals, that wash off of people in the ocean, contribute to coral bleaching – a process that subjects coral to stress and possible mortality. The ban of chemical-based sunscreens does not take effect until January 1, 2021, but the signing of the bill raises questions about the effects these chemical-based sunscreens have on human skin. If sunscreen chemicals washing into the ocean leads to coral bleaching, these same chemicals may also have a hugely negative impact when absorbed into human skin.
Effective sunscreens come in two varieties, a mineral-based formula and a chemical- based formula. Chemical-based sunscreens contain chemicals such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate, while mineral-based sunscreens contain zinc oxide and titanium dioxide. Mineral-based sunscreens create a layer of minerals on the skin to deflect the sun’s harmful rays. Instead of deflecting the sun’s rays, chemical-based sunscreens create a chemical reaction absorbing the sun’s rays releasing it as heat. The state of Hawaii banned chemical-based sunscreens, as they contain the chemicals oxybenzone and octinoxate, both linked to coral bleaching.
Both chemicals, oxybenzone and octinoxate, are FDA approved. The FDA approved the chemicals in the 1980s because there was no definite data showing either of the chemicals were harmful. Both oxybenzone and octinoxate absorb UVB and UVA rays, making them effective in sunscreens, and which helps prevent skin cancer. Oxybenzone and octinoxate have, however, raised health concerns for the last ten years due to the high rates of skin allergic reactions with the chemicals. Many completed studies show potential harmful effects of oxybenzone, though nothing is conclusive. Thus the FDA refuses remove oxybenzone from the list of approved chemicals.
Although these chemicals are FDA approved, recent media attention has exposed the possible harmful effects. The Environmental Working Group (“EWG”) has released ratings of chemicals in sunscreen to express the toxicity of each. The EWG gave oxybenzone a rating of 8 out of 10 (10 being the most toxic) due to studies linking oxybenzone to hormone disruption and cancer. None of the EWG’s studies were conclusive, but they created enough concern to cause the EWG to evaluate chemical sunscreens. One study in 2001, involved feeding rats oxybenzone which resulted in changes to the female rats’ estrogen levels. The abnormal estrogen levels led to abnormal uterine growth. The studies also showed oxybenzone potentially reducing sperm production in male rats. EWG further tested oxybenzone on laboratory grown skin. The test results showed a potential link between oxybenzone and cancer because the ingredient in oxybenzone that absorbs UV rays had the potential of releasing free radicals that could damage nearby cells, leading to cancer. Although none of EWG’s studies show a definite causal connection between oxybenzone and harmful effects, the chemicals in sunscreen have still raised enough concern to warrant further testing because sunscreen is still absorbed directly into the skin and can affect internal organs.
Although oxybenzone and octinoxate have received the most media attention, there are other chemicals in sunscreen with unknown effects for long term use. Some of the other compounds in sunscreen ingredients have been waiting for an FDA review since 2002 because of their unknown potential harmful effects. Some sunscreen distributors already stopped using the natural chemical para-aminobenzoic acid (“PABA”), added to sunscreen in 1970s, because of its potentially negative effects. PABA in sunscreen inconclusively increased skin allergic reactions. PABA was also linked to DNA damage and concerns PABA encouraged the formation of cancer cells. Multiple studies have been conducted on another chemical in sunscreen, homosalate, that were inconclusively linked to hormone disruption, breast cancer cell growth, and the enhancement of pesticide absorption. As these studies are not conclusive, the FDA approved the chemicals, but the FDA should not stop testing based on the inconclusive data. The FDA should demand more conclusive testing for all the chemical ingredients in sunscreen.
Oxybenzone, is no different than other sunscreen chemicals, as it also needs further conclusive studies. Scientists have pointed out flaws in the studies done thus far, that refute that oxybenzone causes harm. The EWG rat study, which showed oxybenzone caused hormone disruption and abnormal uterine growth, gave the rats amounts of chemicals unrealistic in comparison to the amount of oxybenzone an average human would absorb in their bodies through sunscreen use. Scientists dismissed the results because they concluded that humans would not ingest as much oxybenzone in their lifetime as the rats did for that one study. With that being said, testing oxybenzone for possible hormone disruption should not be dismissed. Additional testing should be required on new groups of subjects, over longer periods of time, before allowing the FDA to conclude that oxybenzone has no harmful effects. The other studies that showed oxybenzone released free radicals potentially leading to damaged cells were also dismissed by some scientists because there were too theoretical. The EWG never said the release of free radicals would cause cancer, but the group said it could cause cancer. The possibility that oxybenzone could cause cancer alone should lead to further testing, no matter how theoretical the results.
Looking Forward
Dermatologists fear that if all chemical-based sunscreens are taken off the market in general, the public will be less inclined to use sunscreen altogether, creating more potential for skin cancer and skin damage. The public would neglect to remember the mineral-based sunscreen alternatives that are not absorbed into the skin and do not contain the same concerning chemicals. If the Hawaiian ban takes effect in 2021, the law will test dermatologists’ concerns. Hawaii will be one sample sized area not using chemical-based sunscreens which will show whether there is a decrease in general sunscreen sales, or a change in skin cancer levels.
Hawaii’s new law banning chemical-based sunscreens comes down to the need to balance the risk of skin cancer against the risk of potential harm from chemical-based sunscreens. Although there is a definite link between the sun’s UV rays and skin cancer making sunscreens necessary, that does not mean that chemical-based sunscreens are the only answer, there are still mineral-based sunscreens. For now, chemical-based sunscreens prove to be the most effective protection against the harmful effects of the sun, but scientists, as well as the FDA, should recognize the possibility of harm from these chemicals. They should continue to test the effects of chemicals like oxybenzone and octinoxate, especially when both chemicals appear in other daily-used skin products, like cosmetics makeup. If chemical-based sunscreens still prove to be the only way to effectively prevent skin cancer, the FDA should then at least require sunscreens with oxybenzone and octinoxate to have warning labels that express the potential harms the chemicals could have on the human body.
Ashlyn Dowd is a 2L staff member on the Journal of Health and Biomedical Law. Ashlyn interned at the Somerville District Court and has interests in health law, family law, and criminal law. As a staff member, she is working on a Fall 2018 case comment about the FDA’s role in rejecting changes in drug labeling after approval of the new drug application.
Link for more info: https://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/