INS 551 is silicon dioxide, the food-grade form of silica. It is added in tiny amounts to powders so they stay free-flowing and do not clump from moisture. On Indian packs it shows up in iodised salt, masala powders, instant coffee, milk powder, and powdered drink mixes. It is generally vegan and is permitted by FSSAI for specified food categories.
INS 551 is silicon dioxide, the food-grade form of silica. It is added in tiny amounts to powders so they stay free-flowing and do not clump from moisture. On Indian packs it shows up in iodised salt, masala powders, instant coffee, milk powder, and powdered drink mixes.
Brands use it because Indian humidity ruins powders fast. Salt, masalas, milk powder, and instant coffee will cake into rocks within weeks of being opened without an anti-caking agent. A small amount of food-grade silica absorbs surface moisture and keeps the powder pourable.
INS 551 commonly shows up on Indian packets in these categories:
Food-grade silicon dioxide is an inorganic mineral. It is not derived from any plant or animal source. No animal product is used in its manufacture.
FSSAI: Permitted by FSSAI under Schedule I of the FSS (Food Products Standards and Food Additives) Regulations 2011 as an anti-caking agent for specified food categories with category-specific limits, including a maximum of 2 percent in powdered flavouring substances.
JECFA: ADI 'not specified' for silicon dioxide and silicates as a group, established at 29th JECFA (1985). 'Not specified' is JECFA's safest classification.
On packets, in recipes, and in conversation, INS 551 is also called:
Last verified: 2026-04-30.