Traditional sunscreens contain chemicals like oxybenzone, octocrylene, and octinoxate that wash off into oceans where they damage coral reef ecosystems. These chemicals bleach and kill corals. Approximately 14,000 metric tons of sunscreen hits oceans annually. "Reef friendly" alternatives use zinc oxide or titanium dioxide as UV blockers instead of harmful chemicals. However, there is no legal definition of "reef friendly" and these sunscreens may still contain potentially harmful ingredients. The best options are to minimize sunscreen use by wearing protective clothing and staying in shade, and to read ingredient lists to avoid products containing oxybenzone, octocrylene and octinoxate.

1. What is reef friendly?
The purpose of sunscreen is to block harmful ultraviolet (UV)
radiation emitted from the sun. The UV blockers usually found
in traditional/mass-market sunscreens are oxybenzone,
octocrylene, and octinoxate. The main problem with these
chemicals is that they don’t stay on the body - they wash to
the sea. Approximately 14,000 metric tons of sunscreen hit
the ocean every year. There, they create a variety of problems,
and, in short, are toxic to fish, algae and corals. The chemicals
bleach and kill large populations of coral reefs - living
creatures (not plants) which serve as underwater ecosystems
and breeding grounds. The damage to the reefs causes
dwindling of marine life, reduction of coastal protection , and
diminished recreational value (diving, swimming, marine life
watching, etc).'Reef friendly' sunscreens do not contain the
ingredients above. Instead, they contain zinc oxide and
titanium dioxide as active ingredients (UV blockers).
Being more reef friendly
All sunscreens, even those that are mostly ‘natural’, ‘organic’,
or ‘mineral’, contain ingredients that could jeopardize the
marine environment. To be less harmful for the environment,
while keeping our skin protected, minimize the use of
sunscreen by wearing a hat and long clothes (wetsuit, rash
guard, etc) or simply spend more time in the shade (i.e.
canopy, beach tent). When you do spend time in the sun, try
and use sunscreen that is friendlier to the environment - check
the ingredients of the sunscreen, and avoid buying and using
sunscreen products that contain oxybenzone, octocrylene and
octinoxate.
Challenges
Sunscreens that do not use oxybenzone, octocrylene, and
octinoxate are are commonly referred to as “mineral” or
“natural” sunscreens (as opposed to “chemical” sunscreens).
Like the term “Reef Friendly”, these terms are, to a great
extent, branding / marketing statements rather than scientific
or legal definitions. “Mineral”, “natural” or “reef friendly” does
NOT mean that these products are made with only natural
ingredients. Hawaii, for example, legally banned the use of
sunscreens containing oxybenzone and octinoxate, effective
January 2021. While this is a great first step, it does not ban
the use of octocrylene. In "mineral" sun screens, the size of
the zinc oxide or titanium dioxide particle is the key - micro
particles are considered non harmful to the human skin and
the marine environment. Nano particles are considered
harmful, as their smaller size allows them to infiltrate the
blood stream of humans and sea animals.
Summary
Traditional sunscreens contain several ingredients that
damage marine ecosystems. Alternative sunscreens, though
not perfect, are less harmful. Because there is no regulation
clearly separating one sunscreen from the other, read the
ingredient list on the sunscreen and choose products not
containing harmful ingredients. In addition, use less sunscreen
by wearing suitable water clothing and staying in the shade.
Intro
The term “reef friendly” or “reef safe” is being used
extensively on products and in the news recently, as a part of
the effort to minimize human effect on marine life and habitat
in general, and the effect of certain chemicals found in
sunscreen on corals and reefs specifically. As there is no
legal/regulatory to what "reef friendly" is, this pager aims to
give some clarity on these terms, explain the 'life cycle' of
traditional sunscreens, specify the challenges with the term
and use of 'reef friendly' sunscreen, and suggest ways to
become a more 'reef friendly' individual.
"Reef Friendly" sunscreens in one page
For further reading...
Environmental effects of sunscreen active ingredients
Symbiotic relationship between algae and coral reefs
Comprehensive general explanation
© 2019 Michael Gallant Phot by #dulgier93 Diver's Essentials