Calcium silicate (Ca2SiO4), also known as calcium silicon oxide, is a product derived from limestone and diatomaceous earth.
Used in the pharmaceutical industry as an anticaking agent. Anti-caking agents absorb moisture and allow products to flow freely during the manufacturing process. Silicon dioxide and various silicates occur abundantly in the earth’s crust, are present in practically all natural waters, animals, and plants, and are part of the normal human diet. They are typically used in very small amounts.
The available evidence on the safety of sodium silicate indicates that it is low when consumed at defined concentrations.
None are recorded.
Source: Drugs.com, http://www.drugs.com/inactive/calcium-silicate-13.html