If the amount of sunscreen that ends up in the ocean each year is anything to go on, then it would appear that skin cancer prevention campaigns are paying off. On a global scale, we apply enough sunscreen annually for 25,000 tonnes of it to end up in the ocean says Nicolas Imbert, executive director of Green Cross France.

While that is good news for our skins, it also means we’re having an enormous environmental impact on ocean life. Most sunscreen on the market contains ingredients such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate. These ingredients produce chemical reactions that protect the skin from harmful rays, but some of them are also “toxic to the symbiotic algae that live within corals”. A 2008 study revealed that “sunscreens, by promoting viral infection, potentially play an important role in coral bleaching in areas prone to high levels of recreational use by humans.” It was for this very reason that, on May 1st, Hawaii passed a bill to ban the sunscreens that are harmful to these ecosystems.

Luckily, mineral sunscreen is a good alternative to chemical sunscreen. It uses active mineral agents such as zinc oxide and titanium dioxide to reflect the sun’s light away from the skin. Not only are the ingredients in mineral sunscreen safer for humans (oxybenzone, the most common ingredient in chemical sunscreens, has been linked to allergies, hormone disruption, and cell damage, while zinc oxide is the only active sunscreen ingredient approved for use on children by the FDA), but mineral sunscreens are also safer for the environment.

Some nuance is required here, however. Firstly, just because a particular brand of sunscreen says “mineral” on the bottle doesn’t rule out the possibility that it also contains chemical ingredients that are not reef-safe. Second of all, some mineral sunscreens use zinc oxide and titanium dioxide nanoparticles to make them more spreadable and appear less white on the skin, but the mineral ingredients must be “non-nano” in size to be considered reef-safe. If they are below 100 nanometers, the creams can be ingested by corals” and transform into hydrogen peroxide when exposed to the sun, generating high levels of stress on marine phytoplankton. What’s more, Hillary Peterson of the Huffington Post points out that “nanoparticles of anatase titanium dioxide break down in the presence of UV and water to generate free radicals. Since some skin cancers are linked to damage done to the skin by free radicals this is cause for concern.”

It would be convenient if choosing a sunscreen were as simple as “chemical equals bad and mineral equals good”. With so much to take into consideration, it can be complicated to make the right choice as a consumer, so here are 7 reef-safe (read non-nano zinc oxide) sunscreens to wear this summer:

1. All Good – SPF 50+ Water Resistant Zinc Sunscreen Butter

2. Badger Balm – Sport Sunscreen Cream SPF 35

3. Poofy Organics – THE Sunscreen

4. Raw Elements – FACE + BODY 30+ TUBE

5. Devita Skin Care – Solar Body Moisturizer SPF 30+

6. Mad Hippie – Facial SPF

7. Living Libations – Everybody Loves The Sunshine With Zinc