An estimated 8,000 to 14,000 metric tons of sunscreen washes off swimmers’ bodies annually, causing damage to fragile aquatic ecosystems—particularly coral reefs.
Why does it bypass wastewater treatment facilities?
Although individuals living inland may not have direct contact with the ocean, their sunscreen might. Oxybenzone is an active ingredient found in many products—including sunscreen—that is absorbed into the skin when applied, and can be detected in urine 30 minutes after sunscreen application.
This means that when you go to the bathroom or take a shower, the chemicals in your sunscreen are washed down the drain and into wastewater treatment facilities. Oxybenzone, octinoxate, and many other sunscreen chemicals bypass our wastewater treatment facilities and end up back in the environment.
The chemicals travel downstream eventually reaching the ocean, where they have toxic effects on coral, including endocrine disruption, DNA damage, and even death. Oxybenzone can also exacerbate coral bleaching by weakening the corals and increasing their susceptibility to bleaching.
Since applying sunscreen is a common practice for outdoor recreation, the chemicals found in most sunscreens are directly washed into our rivers, lakes, and ocean.
Here’s what might be in your sunscreen
- Oxybenzone/benzophenone-3 (BZ): Found in many sunscreen products to block UV rays, over 50 studies have shown it to be harmful to reproduction and overall health of many animals, including mammals and corals.
- 4-methylbenzylidene camphor (MBC): Often added as a UV blocking chemical to sunscreen lotions and a myriad of other cosmetic products, even though it is not allowed by the US Food and Drug Administration (FDA) to be used as a sunscreen ingredient in sunscreen products for human topical use. Because of a loophole, it can be added to sunscreen lotion as a UV-stabilizer for fragrances, with some products containing up tp 2.5% or more. MBC does contribute to the overall SPF rating, but it should technically not be allowed to add to this contribution.
- Octinoxate (also called octyl methoxycinnamate): Used as a legal UV-blocking ingredient, though a number of studies have shown it to be an endocrine disruptor.
- Avobenzone: A less stable derivative of oxybenzone, avobenzone is a less effective UV absorber than oxybenzone. When added to a product containing octinoxate, it will rapidly break down in the presence of light. At the moment, there are almost no studies on the ecotoxicity of avobenzone, though a recent study presented at a conference in 2016 by L’Oreal concluded that avobenzone, like oxybenzone, could induce coral bleaching.
- Polyethylene (specifically polyethylene microbeads): meant to add a “luxurious” and smooth feel to sunscreen (and many other personal care products), polyethylene microbeads are tiny pieces of plastic that ultimately end up on our waterways and the ocean. Thankfully, microbeads have recently been banned and will be phased out by 2018.
- Homosalate: Another popular and legal UV-sunscreen ingredient. Very little is known about its toxicity, though several studies have shown it to be an estrogenic endocrine disruptor and an anti-androgenic endocrine disruptor, both of which can cause changes to the endocrine system and to hormonal balance.
- Octisalate: A popular UV-sunscreen ingredient of which very little is known about its toxicity, particularly regarding long-term exposure, but which can also act as an endocrine disruptor.
- Octocrylene: Very little is known about the toxicity of octocrylene to either humans or wildlife. Studies exist on mammals which were done predominantly by Proctor & Gamble, and which concluded that octocrylene is being safe. However, a study published in the journal Chemosphere demonstrated that octocrylene (1) can accumulate to high levels in fish, (2) it acts as a “double threat” endocrine disruptor causing anti-estrogenic and anti-androgenic activity, and (2) cause reproductive toxicity.
- Parabens: There are at least six different parabens that are used as product preservatives. Parabens induce a number of toxic effects in humans, corals, and other species. First, it is known to be an estrogenic endocrinee disruptor. Second, it can cause oxidative damage to DNA, meaning that it causes mutations and can induce proliferation of some types of cancer cells, particularly breast cancers. Third, it is associated with a significant drop in male infertility by damaging the mitochondria of sperm.
- PABA (para-aminobenzoic acid): PABAs come in a number of different chemical derivatives. They are another UV-sunscreen chemical, but because of consumer avoidance of this chemical, many manufacturers have removed it from their products. It causes allergic contact dermatitis, but the primary concern centers around a number of studies that show PABAs of being broad-range endocrine disruptors. Besides acting like an estrogen, it has also been shown to disrupt thyroid function. Finally, there is evidence that it may also be genotoxic, causing damage to DNA.
Like many compounds, certain individuals are allergic to titanium dioxide and zinc oxide. However, these ingredients are known for being used in products for sensitive skin. Like any product, be observant of effects and stop use if you experience irritation.
A good rule of thumb is testing a small amount on your arm and if you begin to get irritated, then try finding sunscreens with just zinc oxide or other natural ingredients.
Nanotized titanium dioxide and zinc oxide pose a threat to human and wildlife health. Both oxides can induce oxidative damage when exposed to sunlight. Zinc oxide in a nanotized form has been shown to induce coral bleaching.
Many sunscreen ingredients, including oxybenzone, are readily absorbed through the skin and are thought to be endocrine disruptors that affect users' hormones and reproductive functions.
Multiple active ingredients in sunscreen have been proven to contribute to the bleaching of coral. Coral bleaching occurs when there is an increase in temperature or other stress factor like pollution that stresses the algae of the coral and causes the coral to expel the algae. The algae in the coral is its source of food and is what gives the organism its vibrant color, so once it’s gone the coral become white or “bleached.” This process reduces the ability of corals to reproduce. It also damages coral DNA, which can lead to deformities. Ingredients like oxybenzone also act as an endocrine disruptor that cause coral larvae to encase themselves in their own stony skeleton during a crucial development time.
Coral reefs are already under great threat from pollution, overfishing, development, runoff, ocean acidification, disease, and more. Avoiding toxic sunscreen is one way you can help to protect the ocean and marine life for future generations.
Oxybenzone is toxic to fish and can result in the feminization in fish—both aquatic and marine. Male fish over time take on female attributes, making reproduction difficult and contributing to disease. Just remember—if it’s toxic to marine life and the environment, it’s probably not great for your health too!
Calculate Your Impact
To calculate the total potential pollution load of sunscreen chemicals, such as oxybenzone, at a particular dive site or beach, consider this simple equation:
(# of swimmers per day at a site) X (18 grams of sunscreen per person) X (number of hours) =
Amount in grams of sunscreen lotion that contaminates a site
(Amount of grams of sunscreen lotion at site) X (6% - the amount of oxybenzone in many lotions) =
Total Potential Amount in grams of oxybenzone at that site per day
Non-Nano vs. Nano
Nanoparticles are fragments of a material that are smaller than 100 nanometers (nm). For conversions, one nanometer is equivalent to one-billionth of a meter. In order to determine if a product is nano or non-nano, companies may use scanning electron micrographs, sedimentation analysis, surface area calculations, and light scattering analysis to determine whether particles size is greater or less than 100 nm.
In the US, the FDA has not defined nano and non-nano products, though the European Union and Australia has defined nanoparticles as less than 100 nm. The Environmental Working Group suggests using non-nano products over nano. The controversy of nano versus non-nano products lies in the ability for nanoparticles to be absorbed through the skin and enter the body and bloodstream, increasing the risk of nanoparticles disrupting cell walls and tissues. Non-nano based products are recommended since they lie on the skin's surface and do not pose any harm compared to nano products.
EU and Australia (Badger, Goddess Garden statements http://www.badgerbalm.com/s-33-zinc-oxide-sunscreen-nanoparticles.aspx
Non-nano zinc oxide and titanium dioxide are considered better active ingredients in sunscreen compared to oxybenzone and other chemicals used in 80% of commercial sunscreens. Zinc oxide is a compound naturally found in nature but is rare, and therefore companies produce it in a lab to make a ‘natural identical mineral.’ Other natural ingredients in sunscreen include plant oils and butters which all have varying SPFs.
There are 17 FDA approved ingredients that can be used as “Active” ingredients in sunscreens. Oils and butters don’t contribute significant SPF to a product.
Beware of products labeled biodegradable or environmentally friendly. Although they may break down faster than other products, the amount of time they spend in the ocean can still harm corals and other organisms. When choosing a sunscreen, ignore the labels on the front that can be misleading and take the time to look at the active ingredients listed on the back. Avoid products containing oxybenzone or any other chemicals listed above and avoid sunscreens that use nano zinc or titanium dioxide
Just Cover Up
Apart from applying sunscreen, there are other steps one can take to protect from the sun’s harmful rays. Wearing hats, covering up with light weight clothing, wearing rash guards while in the water, staying in the shade, and choosing to be active in the morning or evenings will reduce your exposure to the sun's rays.
If you want to try and make your own homemade sunscreen, there are many resources on the web or at your local health food store. We do not recommend depending on homemade recipes before you fully test their potency and protectability on your skin. Below is a link to start your search if you are interested in exploring natural sunscreen recipes.
When purchasing sunscreen also keep in mind if you’re able to recycle the product or even refill it. Buying sunscreen in bulk can save you money and reduce the amount of packaging used. Avoid buying sunscreen in aerosol containers, because more product will end up on the sand and in the environment rather than on your skin.
Goddess Garden, Stream2Sea, All Good Products & Badger are all products that are better options for yourself and the environment. Besides containing either non-nano zinc oxide or titanium dioxide these products also include aloe, oils, and other natural ingredients.
List Approved by EWG:https://www.ewg.org/sunscreen/best-sunscreens/best-beach-sport-sunscreens/?tag=2012SunscreenAd&gclid=CjwKEAjwzJexBRCa_pGo8IK0ilASJABfGldbXkkfSWmqKOM26kGspnYFtKJKPFxXAEZKxDUK4X2iERoC1Lnw_wcB
Craig A. Downs, Ph.D.
Executive Director, Haereticus Environmental Laboratory
Chairman, Global Coral Repository