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.

A low dose of Stream2Sea’s Coral Care sunscreen has a positive effect on coral growth incomparison to control sunscreen treatment, according to research done by Dr. Michael J.Sweet, Professor of Molecular Ecology and Head of the Nature-based Solutions Research Centre at University of Derby. Co-founder of the Coral Spawning Lab. View Fact Book View Summary Report

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

USDA Biobased testing measures the percentage of renewable biological ingredients in a product, ensuring it is derived from plants and other sustainable sources rather than fossil fuels. Products that meet the rigorous USDA BioPreferred® standards earn certification, verifying their commitment to reducing environmental impact. At Stream2Sea, this certification is important because it aligns with our mission to create safer, more sustainable personal care products that protect both people and the planet.

At Stream2Sea, we proudly offer products that are EWG Verified®, a mark that reflects our commitment to your health and the environment. This certification means our products meet EWG's strictest health standards, with no harmful chemicals of concern and full ingredient transparency. When you see the EWG Verified® label, you can trust that our products are safe, effective, and free from ingredients linked to health risks. It's a promise we stand by—safe for you, safe for the planet.

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.

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. Learn More on the Protect Land + Sea page

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.

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.

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.

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.

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.

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.

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

At Stream2Sea, we prioritize transparency and quality. Every batch of our sunscreen undergoes rigorous third-party testing to verify that the mineral content precisely matches our declared specifications. This ensures you receive the correct level of SPF protection, providing the safety and effectiveness you expect from our reef-safer formulations.

Stream2Sea performs random lot testing for heavy metals and other potential contaminants. Results consistently show non-detectable or minimal trace levels, well within FDA, Prop 65, and ICH Q3D safety guidelines. Mineral-based sunscreens have the potential for heavy metal contamination, which is why we take extra precautions at Stream2Sea. Our minerals and final sunscreen formulations undergo rigorous third-party testing to ensure they meet strict safety standards. This commitment guarantees the purity and safety of our products for both you and the environment.

Every aqueous formula produced by Stream2Sea undergoes thorough microbial testing to ensure it is free from contamination before being released. Additionally, each formula is subjected to extensive microbial challenge testing during its product development, verifying that it will remain clean and safe throughout its intended use. This rigorous process guarantees the highest standards of product integrity and consumer safety.

Our formulas are carefully developed to be gentle and safe for even the most sensitive skin. Most have undergone patch testing to validate our ‘safe for sensitive skin’ claim. However, individual sensitivities can vary, so we always recommend conducting a patch test before full application. A small area inside the elbow is an excellent spot to trial any new formula before applying it to your face or body.

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.

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.