Sunscreens can be broadly divided into two separate groups; chemical or mineral (often called physical sunscreen). While mineral sunscreens like CO SAINT work by sitting on the skins surface and reflecting UV rays like a mirror through either zinc oxide, titanium dioxide or a combination of both, chemical sunscreens work like a sponge to soak up the suns harmful UVA and UVB rays. Chemical sunscreens contain one or more of the following active ingredients to absorb the suns rays: oxybenzone, Benzophenone-1, Benzophenone-8, OD-PABA, 4-Methylbenzylidene camphor, 3-Benzylidene camphor, Octisalate, Octocrylene, Homosalate, or Octinoxate.
Oxybenzone and octinoxate have been flagged as potential endocrine disruptors and both chemicals are on the European Union (EU) Cosmetics Directive, with oxybenzone having a 10% maximum authorized concentration (MAC), and octinoxate having a 6% MAC. Endocrine or hormonal disruption can cause cancerous tumours, birth defects and other developmental disorders.
While the jury is still out on whether these level of chemical ingredients are safe for humans, we know they are harmful for marine ecosystems. Whenever a wearer of these sunscreens enter the water either for swimming, surfing, diving, any other water-sports and even when people wash in the shower after sun bathing these chemicals enter the marine ecosystem and cause a whole host of problems. Oxbenzone in particular has been found to be highly toxic to juvenile corals and other marine life, worsening the effects of climate change. Which is why these chemicals have been banned in the Virgin Islands and Palau, while Hawaii will bring into law in 2021 the ban on over the counter chemical sunscreens. Lets's hope we see the EU also make moves to protect the planet's marine ecosystems in the near future too.
While you may not be too concerned about tropical coral reefs here in Ireland be aware that when a sunscreen is marketed as ''reef-safe'' we are not just talking about protecting coral reefs but many forms of sea life such as green algae, mussels, sea urchins, dolphins and a wide range of fish which are all found on our coasts. Algae produces the majority of the world's oxygen and are a base food for sea life. So it's pretty fundamental! Whatever brand of sunscreen you use, please try and choose a non-nano mineral UV filter rather than chemical.
Pictured above is zinc oxide magnified 150000 times. Pretty stuff!