You may have seen these names: oxybenzone and avobenzone on the back of your sunscreen bottle, and you may have wondered what they are. They are chemical active ingredients in sunscreens. They provide sun protection by absorbing UV radiation from the sun and converting it into heat and then releasing it from the skin. Oxybenzone is the most popular chemical sunscreen ingredient in the US market. 

Oxybenzone is an organic compound that can also be found in plastics and toys. It has been flagged by the Environmental Working Group as a concerning ingredient because it has been found in animal studies to be a potential hormone disruptor, and further it has been found to be absorbed in large amounts through the skin. Oxybenzone has also been found to be an allergenic and cause high rates of skin reactions. 

Similarly, avobenzone is also a chemical sunscreen ingredient. However it is one of only two UVA blockers on the market, the other being zinc oxide. The downside of avobenzone is that it breaks down in the sun in 30 minutes and decreases in effectiveness. When avobenzone degrades from sun exposure, it results in harmful free radicals being released into the body, which can accelerate aging and increase risk of illness including cancer. Despite this, more research needs to be done on the impact to human health, and wearing sunscreen with oxybenzone or avobenzone is better than no sunscreen at all in protecting from skin cancer.

Aside from the potential health impacts, both of these chemicals have been found to cause harm to ocean life. The National Oceanic and Atmospheric Administration (NOAA) has found that chemical sunscreen ingredients cause harm to coral reefs, cause reproductive problems in fish, damage sea urchins, and can accumulate in the tissues of dolphins. Resulting in the ban of sunscreen containing these ingredients, among others, in Hawaii.

Make sure to check the ingredients of your next bottle of sunscreen!