It’s official! On Tuesday, July 3, 2018, Hawaii Governor David Ige signed the first bill in the United States that will ban the sale and distribution of chemical-based sunscreens that contain oxybenzone and octinoxate. The ban goes into effect in January 2021.
There are two types of sunscreen: chemical and mineral. The main difference between them is how they protect us from the harmful UV rays produced by the sun.
Some sunscreens use chemicals like oxybenzone, octinoxate, and avobenzone, which mostly absorb UV rays. Others use minerals like titanium dioxide and zinc oxide to absorb, scatter and reflect UV rays.
Many sunscreen formulas contain a mixture of both chemical and mineral UV filters to ensure broad-spectrum coverage.
Despite mineral sunscreens providing better overall sun protection, chemical-based sunscreens tend to be cheaper and more popular amongst consumers because they absorb into our skin well and don’t leave a white residue like mineral-based sunscreens.
Since the sunscreen market’s growth over the past 80 years, scientists have expressed concerns of sunscreens for both human health and the state of the marine environment that ultimately become the repository of such products.
Sunscreens that use chemicals to protect us are thought to have “endocrine disrupting” properties, meaning they can cause a hormonal imbalance and / or cause allergic reactions in people.
Approximately 4,000-6,000 tons of sunscreen are discharged into coastal waters every year. At this magnitude, it is obvious that sunscreens are making an impact on marine life, but the question is how much.
From a review of 40 studies, results indicate that chemical-based sunscreens (not just oxybenzone and octinoxate) can be considered harmful to marine life.
However, sunscreen toxicity will differ depending on the species it encounters, including external factors such as water temperature, salinity, pH, and weather.
Toxicity is dose-dependent: how harmful a substance is depended largely on how much of it is exposed to an organism. This is particularly important for corals since they are very sensitive to contaminants due to their thin outer tissue.
Craig Downs, a forensic ecotoxicologist, has long advocated for the ban of chemical-based sunscreens to protect coral reefs. According to his research, coral planulae (baby corals) exhibit increased rates of bleaching in response to increased exposure to oxybenzone. Bleaching is a term used for corals that have lost the majority of their symbiotic algae, called zooxanthellae (zo-zan-thell-ee).
Corals may not necessarily die directly from exposure to chemical toxins such as oxybenzone and octinoxate, but the stress they endure from the exposure can make them more susceptible to disease and other environmental stressors such as climate change, which can and do kill them.
There is still a lot to learn about the toxicity of sunscreens, including how much sunscreen is present on our reefs, where the chemical contamination is coming from, how to accurately measure it, and how to remove it.
What we do know is that chemical-based sunscreens should be avoided altogether, and mineral-based sunscreens that only contain non-nano zinc oxide or non-nano titanium dioxide should be used.
Mineral sunscreens are not perfect, but their effects on humans and marine life are far less severe. Hawaii’s ban on oxybenzone and octinoxate is a great step forward, but other states and countries should continue this trend in order to make a global change.
As a consumer, being conscious of the products you buy can make a big difference! Additionally, wearing protective clothing and minimizing sun exposure is conceivably the best option for you and the oceans.
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4Ocean is partnering with SeaLegacy throughout the month of August to advocate for marine protected areas and support sustainable fisheries around the world.