How safe is silica?
Silica is the chemical compound silicon dioxide, an oxide of silicon. Silica is most commonly found in nature as sand or quartz, as well as in the cell walls of diatoms (as in diatomaceous earth. It is the most abundant mineral in the Earth's crust.
Silica is used primarily in the production of window glass, drinking glasses and bottled beverages, as well as optical fibers for telecommunications. It is a primary raw material for many ceramics including earthenware, stoneware and porcelain, and industrial Portland cement. Silica is common additive in food products, where it is used primarily as a flow agent in powdered foods, or to absorb water.
I know of no harmful effects from digesting silica in foods or supplements. In fact, it is sold as a mineral supplement.
Silicosis is a disabling, nonreversible and sometimes fatal lung disease caused by overexposure to breathing large amounts of crystalline silica, such as amounts you would be exposed to in workplace exposures.
It is not toxic, it is a particle hazard. You wouldn't be exposed to this amount at home.
This answer was provided by our friend, Debra Lynn Dadd. Hailed as "The Queen of Green" by the New York Times, Debra Lynn Dadd has been a pioneering consumer advocate since 1982, specializing in products and lifestyle choices that are safer for human health and the environment. She is the author of Home Safe Home.