What is E551?

Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, and is commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. E551 sits in the E500–E599 series, which in the EU classification mainly covers acidity regulators and anti-caking agents.

What is E551 used for?

E551 belongs to the anti-caking agents group. Anti-caking agents stop powders clumping, as in salt and spices.

Is E551 safe?

E551 is considered safe at the levels used in food and is approved for use in the EU. “Safe” means it is approved in the EU and regarded as safe at the levels used in food.

How E551 appears on labels

On food packaging you'll find E551 either as the number “E551” or by the name “Silicon dioxide” in the ingredient list, often after its function. Ingredients are listed in descending order by weight, so an additive near the end is present only in small amounts.

Is E551 vegan?

Yes, E551 is suitable for vegans.