On Friday, a customer sent us a copy of an article questioning the safety of titanium dioxide, the active ingredient in all Stream2Sea reef-safe sunscreens published in the peer-review journal Radiation and Oncology. The science nerds on our team jumped on it immediately, expecting to hear from thousands of other customers. We knew we needed to review the issues and “translate” the science to readable English. Turns out the story was originally published in 2011 – and focuses on nanoparticles of titanium dioxide, which we have never, ever even considered using. We’d reviewed and considered previous work showing that it, and other nanoparticles, poses a clear and present danger to people. Nano-titanium and nano-zinc particles may be absorbed by the human body and the aquatic environment. They cause oxidative stress (think free radicals) that may lead to cell damage, genotoxic effects, inflammatory responses and changes in cell structure. We did learn one very important fact buried in the back of the report: “Current legislation does not require labeling whether the products contain nano-sized titanium dioxide or zinc oxide.”