What is e 551?

E 551 is the European food additive code for silicon dioxide (SiO2), also known as silica or quartz. It is a naturally occurring mineral that is commonly found in rocks, sand, and clay. Silicon dioxide is often used as an anti-caking agent and to improve the flow of powders, such as in spices, coffee creamer, and powdered sugar. It is also used in the manufacture of some food packaging materials to keep moisture out and prevent spoilage. Silicon dioxide is generally considered safe for consumption in small amounts as a food additive, but excessive exposure to airborne particles of silica can be harmful to human health.