E551 - Silicon dioxide
By the Daat team · Updated October 30, 2026
E551, silicon dioxide, keeps powders from clumping.
Spice mixes, soup powders, salt and drink powders. Without it the powder would cake into a lump after meeting a little moisture.
How common is it? 0.9% of the products we checked, 147 in all, led by meat products and savoury snacks.
E551 at a glance
| Fact | Value |
|---|---|
| Name | Silicon dioxide |
| Also listed as | silica |
| Function | Anti-caking agent |
| Origin | Plant, mineral or synthetic |
| Vegan / vegetarian | Yes / Yes |
Is E551 vegan?
Yes. E551 has no animal source, so it suits both vegans and vegetarians.