Biodegradable Sunscreens & Bodycare Must Be Tested to Determine Safety

How can you be sure what the best reef-safe sunscreen is?

Made with Natural Ingredients. Biodegradable. Reef-safe. Chemical free. Green.
These are all very loosely regulated claims with respect to sunscreen safety.

We have learned that you can not simply trust that what is on the front of a label is truthful.

Certain ingredients in sunscreens like oxybenzone, avobenzone and octinoxate are toxic to corals and reef fish, but are still in products that are falsely labeled as reef-safe and biodegradable.

Going beyond Reef-safe: Why We’re Reef Safer*

Since our inception, we’ve boldly challenged the definition of “reef safe”. The term is increasingly used to mislead consumers to buy sunscreens that may not at all be “reef safe”.

Backed by science, Stream2Sea rigorously tests our products to maintain efficacy, and formulates to be biodegradable and as safe as possible for you and our waters.

We believe in transparency and education, and hope that when consumers encounter our Reef Safer* label, they’ll be inspired to delve deeper into the issue, making informed choices rather than being swayed solely by trendy labels.

Fact: Certain ingredients in biodegradable sunscreens are toxic to corals and reef fish, but are still in products that are falsely labeled reef safe.

Stream2Sea Product Test Results

Stream2Sea has the only products in the world tested and proven safe for C. elegans, freshwater fish, saltwater fish and coral larvae. When it comes to safety, you can guess or you can know. We like to know.

USDA BioBased Certification

The BioBased Certification is just the latest in our commitment to complete transparency with our formulations. Since starting Strem2Sea in 2015, we’ve been a national leader in developing Reef-Safer™ sunscreens and working with third parties to document the safety and sustainability of our formulations. Professors at Eckerd College in St. Petersburg (my alma mater) created the world’s first-ever tests to show that our products are safe for fresh and saltwater fish, then coral larvae. We worked with Craig Down’s Haereticus Environmental Labs to become one of the first sunscreens to earn their Protect Land+Sea designation. We were among the first sunscreen companies to earn the EWG Verified label.

stream2sea 100 biobased

WetBoost™ Technology Before and After Immersion

Most sunscreens lose 30 – 60% of their sun protection after 80 minutes in the water, but NOT Stream2Sea! Besides the fact that our new Every Day Mineral Sunscreens go on light and sheer, these formulas are so water-resistant, that they actually perform BETTER after you go for a swim!

“Advantageously, the sunscreens described here may surprisingly and unexpectedly exhibit an increase in sun protection factor after being immersed in water.” — Report

1,4-Dioxane Free

1.4-Dioxane is a chemical that is a suspected carcinogen and is often found in shampoos and foaming products. Stream2Sea is free from 1,4-Dioxane.

Hand Sanitizer Test

Many studies have found that sanitizers with an alcohol concentration between 60–95% are more effective at killing germs than those with a lower alcohol concentration or non-alcohol-based hand sanitizers. Our formulas contain a minimum of 62% ethanol in accordance with the FDA monograph recommendations and is enriched with supporting botanicals. To meet the claim of killing more than 99.9% of bacteria, the formula must kill the germs within 60 seconds. Ours was effective at the lowest level tested of only 15 seconds.

Our hand sanitizer was consistently effective in exerting bactericidal activity with a greater that 99.9% reduction against Staphylococcus aureus and E. coli.

Protect Land + Sea Certification

Haereticus Environmental Lab created the Protect Land + Sea (PL+S) certification because selecting a reef-safe sunscreen is more challenging than it should be. HEL is a non-profit, scientific organization whose mission is to conserve wildlife and ecosystems. If a product wears the Protect Land + Sea Certification Seal, consumers, park rangers, and businesses can rest assured that a product does not contain ingredients that may be harmful environmental pollutants.

Broad Spectrum / Critical Wavelength

Stream2Sea SPF formulas exceed the FDA limits for the Broad Spectrum rating. UVA rays can contribute to skin cancer including melanoma. We had our formulas third party tested by an FDA testing facility to determine the level of UVA and UVB protection.

Critical wavelength is an international rating system for UVA protection. A sunscreen with a critical wavelength over 370 nm is considered by the FDA to provide excellent UVA protection. Stream2Sea SPF 30 Sunscreen has a critical wavelength of 380 nm.

SPF 20 has a critical wavelength of 381. Stream2Sea SPF sunscreens are broad spectrum rated.

Biodegradable Does Not Mean Non-Toxic

It is important to know that just because a product is biodegradable for example, a biodegradable sunscreen, does not mean that it is non-toxic. There are several tests to measure a product’s biodegradability, and most are designed to analyze the product’s ability to breakdown in wastewater treatment facilities. To be considered ‘readily biodegradable’, the product must break down into its natural state from 60-80% in 28 days.   ‘Inherently biodegradable’ means it will break down from as low as 20% to 60% in 28 days. So if a product says it is ‘biodegradable’, that is a good first step to knowing that the company is looking at its product’s environmental breakdown.  However, it’s important to understand that you cannot measure a product’s safety just by looking at its ability to biodegrade. That said, it was important for us to know that our products would, in fact, biodegrade in their natural environments, so we tested in both fresh water, as well as salt water.

Aquatic Toxicity and Safety

We began by testing on C. Elegans, simple nematodes, which are ideal for rapid, predictive screening on inflammatory ingredients. We then moved on to freshwater and saltwater fish species, looking at the impact on the fish’s eating behavior, swimming behavior and, of course, mortality rates. Our studies were prepared and conducted by the EcoTox team at Eckerd College. The test subjects were fed at the same time every day and the same amount of food for 96 hours. The fish were exposed to the highest concentration of product that any marine animal or plant would ever naturally come into contact with. For each test, we added a competitor’s product to one group of subjects, the second group was exposed to the same concentration of Stream2Sea’s biodegradable sunscreens and product, and finally, the control group was not exposed to any foreign products. During every observation period, mortality rate, feeding behavior and swimming behavior was recorded. These experiments were done for each of our products before determining their safety. We were pleased to note that our sunscreen did not generate any mortality.

Swimming Behavior in Fishes

What these results show is that swimming behavior with Stream2Sea biodegradable mineral sunscreen is relatively unaffected, whereas the competitor sunscreen most definitely altered the fish’s swimming behavior. Baitfish may be sluggish in the water and not as responsive to their environment. In the wild, sluggish fish would be more vulnerable to predators, and less likely to find or compete for food.

Feeding Behavior

What these results show is that feeding behavior with Stream2Sea shampoo & bodywash is relatively unaffected, whereas the competitor shampoo most definitely altered the fish’s desire to feed.

Coral Larvae Settlement Tests

Stream2Sea biodegradable mineral sunscreens (SPF 20 and 30) did NOT significantly decrease larval settlement, compared to the positive settlement control. The equivalent concentration of Brand X significantly inhibited larval settlement.

Tests Summary of Biodegradable Sunscreens and Products

We set out to create the safest product line of biodegradable sunscreens and bodycare possible for us and the environment. Our company is led by a vegetarian and an animal rights activist, yet we realized that the only way to determine if our products would be harmful to fish and other aquatic life was to test them on living animals. Read more about the tough decisions we’ve had to make about product testing through the process here.  In the end, we are very proud of the SAFE products that we have created. You can feel good using our products during all your adventures, in the backyard or while exploring our beautiful planet blue.

Particle Size Distribution

Stream2Sea biodegradable and reef safe mineral sunscreens are independently verified to contain only NON-NANO particles of titanium dioxide. The X-Axis on these charts are in microns. 100 nanometers equals 0.1 micron. Both plots show nothing below 100 nanometers or 0.1 microns.

Benzene Free Manufacturing

Stream2Sea Sunscreen and After Sun Gel did NOT contain any detectable levels of benzene.

Scientific Tests and Resources

Scientific Test Results


  • Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands. Archives of Environmental Contamination and Toxicology. Downs C.A. et al. 2015 October. Summary of test results.  Also: Full Text.
  • Sunscreens Cause Coral Bleaching by Promoting Viral Infections. Environmental Health Perspectives. Danovaro R, et al. 2008 April. Full Text
  • The Impacts of Sunscreens on Our Coral Reefs. National Park Service. Sunscreen Bulletin