An estimated 14,000 tons of sunscreen enter rivers and oceans every year. In a peer to peer piece, we discuss: what are the best products to use?

Seth Doyle

You might ‘leave no trace’ on the banks when you go for a swim – but have you ever worried about what you are leaving behind in the water?

Global use of sunscreen is on the rise, and while the need to protect skin from the sun is a given, sunscreens are under increasing scrutiny for their potentially damaging effect on aquatic environments.

Last year, Hawaii announced it would ban the sale and distribution of sunscreens containing two common ingredients, oxybenzone and octinoxate. Florida’s Key West followed suit, with both laws due to come into effect in 2021. The Puerto Princesa underground river in the Philippines, one of the New Seven Wonders of Nature, has signs prohibiting the use of sunscreen containing oxybenzone. And some holiday destinations, such as Mexico’s Riviera Maya, insist visitors use biodegradable sunscreen.

It’s estimated 14,000 tons of sunscreen are released into coral reef areas each year, and it’s not just what you wear when you swim that matters: the ingredients in sunscreen enter the ecosystem when we wash them off in baths and showers. 


This feature came out of a question asked on @theoutdoorswimmingsociety Instagram at the start of summer ’19. After a week of research, we have not reached a clear answer on what to buy – but are able to share some of the questions we’ll now ask as we look for products.

One easy win in terms of lowering potential damage to aquatic environments is to lower the amount of sunscreen you use overall, by protecting your skin in other ways: swimming in rash vets and long-arm swimming costumes, staying in the shade, wearing sun hats and covering up, and avoiding the sun during the hottest part of the day. Using creams rather than sprays may also help: spray sunscreens disperse lotion, leaving traces on sand, which ultimately ends up in the water. (Sprayed lotions are also more likely to be inhaled, with some cautious that the nanoparticles of titanium dioxide or zinc oxide in the spray may damage lungs). 

Some people are making their own sunscreen, with ingredients such as Red Raspberry Seed Oil and Carrot Seed Oil claiming to have some SPF protection – but accurately calculating how much sun protection it offers will be harder to do, and skin cancer is a very real health risk.


There are now many sunscreens marketed as reef-safe, marine-friendly, sea-safe, eco-friendly or similar. But all these terms are unregulated. There is only one term that is regulated – the Protect Land + Sea Certification (see below) – so unless you can find a sunscreen with that mark on it (we couldn’t in the UK) the only way to know what is in your sunscreen is to read the labels and do background research. “Reef-safe” sunscreens typically won’t contain oxybenzone or octinoxate, or any of the chemicals known, in reef terms, as the ‘awful eight’ (Octocrylene, PABA (Aminobenzoic Acid), Enzacamene, Octisalate, Homosalate and Avobenzone).  Product claims can produce artificial eco-halo’s: biodegradable doesn’t mean good for the planet, environmentally damaging substances can biodegrade too.

Some of the best information for water users appears to be coming out of the Haereticus Environmental Laboratory (HEL), a non-profit scientific organisation based in Virginia, USA. The HEL group is “dedicated to increasing the scientific, social and economic knowledge of natural environmental habitats in order to better conserve and restore threatened environmental habitats and resources”. HEL has compiled the following list of pollutants that are hazardous to ecosystems, which they update as more research is done. This list forms the basis of their Protect Land + Sea Certification. Products showing this certification are free of the chemicals below: 

  • Any form of microplastic sphere or beads.
  • Any nanoparticles like zinc oxide or titanium dioxide.
  • Oxybenzone: Oxybenzone is a chemical UV filter that can infiltrate underwater ecosystems by washing off skin during a swim or via waste water from showers or taps. It has been banned in Hawaii, Florida’s Key West and Puerto Princesa river in the Philippines. A 2015 study investigating the environmental impact of oxybenzone estimated that between 6,000 and 14,000 tons of sunscreen are released into coral reef areas each year, with 10 per cent of global reefs and 40 per cent of coastal reefs at risk of exposure to this particular chemical.  Oxybenzone was found to damage coral DNA, impede the reproductive process and cause coral bleaching. “We are finding oxybenzone in sea turtle eggs, the fish we eat, shrimp, oysters and clams, and they show an alarming level of toxicity to marine life,” said Dr Craig Downs from HELS in an interview with The Sydney Morning Herald.
  • Octinoxate. Banned in Hawaii. 
  • 4-methylbenzylidene camphor 
  • Octocrylene: Octocrylene is a chemical UV filter shown in a 2014 study to impair developmental processes and liver functions in zebra fish. The possibility of food-chain accumulation was also highlighted as substantial amounts of one chemical, ethylhexyl methoxycinnamate (EHMC), was found in fish and cormorants. Another study revealed that several chemical UV filters caused hormonal changes and reduced fertility in fish.
  • Para-aminobenzoic acid (PABA)
  • Methyl Paraben
  • Ethyl Paraben
  • Propyl Paraben
  • Butyl Paraben
  • Benzyl Paraben
  • Triclosan

For further information on each of these ingredients, see HEL.


Bad news: with no clear consumer certification, we still don’t know what to buy. Good news: a peer group-think on social media has suggested a list of products to investigate. Please look at the labels for further information on what they include:

  • Aethic Sôvée SPF 40 Triple Filter Eco-Compatible Sunscreen: Aethic holds a patent as “the world’s only ecocompatible sunscreen”. Broad-spectrum and photo-stable protection. Contains no nanoparticles, no parabens, no titanium dioxide, no zinc oxide, no petroleum emollients, no lanolin and uses no animal testing. €59/150ml
  • Jason Mineral Sunscreen SPF 30: Hypoallergenic, all-mineral sunscreen that is chemical and fragrance free. Easy to rub in, vegan, biodegradable and cruelty free. £14.99/113g
  • Green People Organic Sun Lotion SPF30: Scent free, broad-spectrum sunscreen with UVA & UVB protection. Plant-based packaging that is fully recyclable. 84% certified organic ingredients. 30p donation to Marine Conservation from each sale. £22.50/200ml
  • Shade All-Natural Sunscreen Non-toxic, non-nano, 100% natural, safe for all skin types. Made with four ingredients to moisturise and protect skin from the broadest spectrum of damaging UVA and UVB rays. £9.75/100 ml
  • REN Clean Screen Mineral SPF 30 Mattifying face sunscreen with broad spectrum UVA/UVB protection, blue light protection, non-nano technology, vegan and made with naturally derived ingredients. £30/50ml
  • Organii Sun Milk SPF 50 UVA & UVB protection, fragrance free, free from nanotechnology, paraben free, water resistant, suitable for sensitive skin, vegan. £23.99/125ml
  • Badger Organics Broad Spectrum Sunscreen SPF 30 Broad spectrum protection from UVA & UVB rays using the zinc oxide. Water resistant for 40 minutes, biodegradable, certified organic base of extra virgin olive oil, beeswax, jojoba & cocoa butter. £11.65/87ml
  • Surfers Skin Mineralised SPF 30 Sunscreen Waterproof, broad spectrum sunscreen with UVA & UVB protection. Sweatproof formula, non-greasy, 2+ hours of protection. Contains manuka honey and aloe vera. £10.45/125ml


Chemical sunscreens absorb light whereas mineral sunscreens, made using zinc oxide or titanium dioxide, reflect it.

Zinc oxide sunscreens were traditionally thick and white, sitting on the skin rather than being absorbed. However, today’s lotions are often made with nanoparticles to give greater transparency, and some still contain chemicals on the HEL list. Nanoparticles in sunscreen are controversial as some studies have found that, in large doses, they can cause cellular damage. Sunscreens made with ‘non-nano’ particles are available and believed to be safer as these particles are too large to enter the bloodstream. 

  • If you are able to take this feature to the next level, then please email updates or product details to us.


  • UVA radiation penetrates skin more deeply than UVB and is responsible for sun-related ageing, as well as having links to skin cancer.
  • UVB radiation targets the superficial layers of skin, causing sunburn. It is also connected to skin cancers.
  • SPF means ‘sun protection factor’ and refers mostly to protection from UVB or sunburn. Experts recommend SPF 30 or higher.
  • UVA star system refers to the ratio of UVA to UVB protection. A high star rating doesn’t mean high protection, just that the ratio is similar.
  • Broad spectrum sunscreens protect from both UVA and UVB radiation.
Liz Lowe, Mich Wallis & Kate Rew