The manufacturers of reflective sand have conducted their own safety testing, often called ecotoxicology testing, with no ill effects observed. Our team even went further by conducting our own ecotoxicology testing. We contracted independent labs to test on EPA-representative specimen, meaning one type of specimen is tested to represent a gamut of species. Here are the summarized results:
In our independent testing on EPA-representative avian and aquatic specimen, there was 100% survival at the highest testing threshold. Specimens received far more material than a fish, bird, or mammal would ever come across if the solution was deployed at scale.
Moreover, humans, birds, and fish alike ingest silica regularly. For humans, it is commonly used in digestive supplements and medications to bind pills, fast-food milkshakes to add richness, and powders as an anti-caking agent. Birds look for and select larger grains of silica to aid digestion in their stomachs and fish swim through it at about one part per million of ocean water. Most importantly, because we've all co-evolved with silica, it does not bioaccumulate.
Materials under 10 micrometers (micrometer = one millionth of a meter) are determined to be harmful to human respiratory health. We take in particles like dust above 10 micrometers with every breath, and particles not filtered in the nose come out of the lungs through a mechanism called the mucocillary escalator in the respiratory tract. This system is a wall of mucus in the respiratory tract that catches particles above the 10 micrometer threshold and brings them out of the body. Our reflective sand is far above this threshold, with an average diameter of 35 micrometers and a perfectly-spherical shape, so that if inhaled by any creature, it will be expunged by the mucocillary escalator.