Is sunscreen hazardous for our health and the environment?

What are avobenzone, oxybenzone, octocrylene and ecamsule? No, they are not new atmospheric pollutants; they are active ingredients in several sunscreen products. A number of studies have shown that, when these chemicals are applied generously to the skin, they are quickly absorbed into the blood. As a result, they could accumulate in the body and be toxic, acting as endocrine disrupters and even causing some cancers.[1]

There are two types of sunscreens: agents that block UV rays and agents that absorb them. The ones called blocking agents, such as zinc oxide and first-generation titanium dioxide, are particularly recognizable by the white patch on the noses of lifeguards at beaches and elsewhere! Despite the esthetics, blocking agents are considered to be both effective and harmless for our health and the environment.

Agents that absorb UV rays, such as oxybenzone, are chemically changed as a reaction to light. The byproducts of those chemical reactions (free radicals) may be harmful for our health and the environment.

This issue was raised with respect to protecting coral reefs, already weakened by rising ocean temperatures. And corals are plentiful in warm water (> 20 °C), exactly where we all want to swim! Several studies have shown net toxic effects of oxybenzone, but only at high doses and under artificial laboratory conditions.[2] It is much more difficult to demonstrate under natural conditions, due to the high dilution level in seawater, the effect of currents and waves, the non-solubility of many products, etc. Although there can be no doubt that some sunscreen ingredients are toxic, they still need to be present in sufficient concentrations on the seabed, which is where corals live.

Nonetheless, the state of Hawaii passed legislation banning sunscreens containing oxybenzone and other potentially harmful ingredients.[3] A few other countries and cities such as Florida’s Key West have followed their lead.

Manufacturers have rushed to sell products that do not contain one or another of the ingredients targeted in preliminary studies, but none have excluded all the “suspects.” According to Quebec’s Chief Scientist, there is a serious lack of robust research, on both sides: There are many factors involved in coral reef degradation, starting with global warming, but sunscreen is not at the top of the list.[4]

Although the benefits of sunscreens far outweigh their harmful effects, they still need to be used properly! And that doesn’t always seem to be the case.

According to Dr. Dawn Davis, a dermatologist at the renowned Mayo Clinic, two tablespoons (30 mL) of sunscreen is barely enough to protect the face, neck and back of your hands, let alone the rest of your body, which you also need to protect when you are wearing a bathing suit! It also needs to be reapplied every two hours, or more often if you have been in the water,[5] no matter how much that little tube cost you at the drug store.

What sun protection factor (SPF) should we use? According to the Canadian Dermatology Association, we should reach for an SPF of 30 and above.[6] On the other hand, SPFs higher than 50 do not necessarily provide an increase in protection.[5]

It is worth remembering that UV rays penetrate through clouds and reflect off water, snow and other surfaces. As a result, outdoor enthusiasts need to think about protecting themselves from the sun not just in the summer months but also in the winter, under sun or cloud!

The industry’s typical response to the concern about “traditional” products being potentially hazardous for the environment is to turn to so-called “natural” sunscreen products. They are generally made using copper oxide or titanium dioxide, two agents recognized both for blocking UV rays and being safe for our health. The other ingredients vary by manufacturer and include various types of oils and greasy substances including coconut oil. Many manufacturers round off their green marketing by using biodegradable packaging or vegan practices.

Natural products often mean DIY products that you can make from ingredients that are relatively easy to find; there are many recipes on the Internet.[7]

Many of these products consist of agents that block UV rays, such as titanium dioxide and zinc oxide, which can be found online from Amazon and other suppliers. But care is needed with DIY products! It is more difficult to obtain waterproof preparations that are going to stay on the skin. Remember that, beyond ecological or economic considerations, the primary role of sunscreen is to protect you from UV rays.

Lastly, remember that in many circumstances, even at the beach, clothing may provide the best possible protection: anti-UV hats, caps, shirts and pants. Other effective barriers include parasols and beach tents. These are effective options that do not need to be replaced every two hours.

When we think of its essential role in producing vitamin D and making fruits and vegetables grow, as well as its significant impact on morale, the sun is a valuable ally, but unfortunately one we have to be careful of. We need to remember that one in five North Americans will develop skin cancer in their lifetime, with the very large majority of cases being caused by exposure to the sun’s UV rays.[8] There are many ways we can protect our skin from the sun all year round, including using sunscreen (blocking, absorbing, all-natural or “commercial” products), covering up (protective clothing, parasols), or staying in the shade. Lastly, we can check the daily UV index and don’t forget to the sunglasses!