Calcium silicate
Calcium silicate suppliers and sourcing guide
Calcium silicate is a white, light, porous powder made synthetically by reacting a calcium source such as lime with silica from diatomaceous earth or sand in water under heat and pressure, then drying and milling the product. Its high surface area lets it absorb several times its weight in water or oil while staying free-flowing. Brands buy it as an anticaking and flow agent for salt, seasonings, baking powder and powder blends, and as a carrier that turns liquid ingredients into powders.
- Also known as
- Silicic acid, calcium salt · Synthetic calcium silicate · E552 · CAS 1344-95-2
- Facts checked
- November 2026
Forms and grades of calcium silicate
Suppliers sell different products under the same name. Specify the one you need.
Food grade
Powder made to Food Chemicals Codex specifications for anticaking use in salt, seasonings, baking powder and dry mixes.
Pharmaceutical grade
Grades meeting the USP/NF monograph, used as a glidant, absorbent and filler in tablets and capsules.
High-absorption carrier grades
Very porous grades sold by oil or water absorption capacity, used to convert liquid vitamins, flavors or oils into free-flowing powders.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Identity
- Tests for calcium and silicate per the FCC or NF monograph, sometimes backed by X-ray diffraction or IR.
- Assay
- Calcium oxide and silicon dioxide content by gravimetric analysis and titration, reported against the monograph ranges.
- Loss on ignition and loss on drying
- Water and volatile content, which affects how much liquid the powder can still absorb.
- Heavy metals and fluoride
- Lead, arsenic and other metals by ICP-MS, plus fluoride, which mineral-based anticaking agents are commonly checked for.
- Absorption capacity and bulk density
- Oil or water absorption and loose bulk density, the main functional specifications for carrier and flow-agent use.
Storage, lots and expiry
Storage and shelf life
Store sealed in lined bags in a dry area, away from humidity and strong odors, since the porous powder readily takes up both. It is chemically stable, so shelf life is mostly about moisture pickup; the supplier sets it, and older stock is retested for loss on drying and absorption capacity.
Lots and expiry dates
Absorption capacity and bulk density can shift between lots and change how much is needed for the same flow or carrier load. Record both per lot, and expect fine dust when charging blenders.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
21 CFR 172.410 permits calcium silicate as an anticaking agent in food at no more than 2 percent by weight of the food, or up to 5 percent by weight of baking powder.
Source: ecfr.gov (opens in a new tab)Health Canada's List of Permitted Anticaking Agents allows calcium silicate as an anticaking agent in baking powder at up to 5.0%.
Source: canada.ca (opens in a new tab)Health Canada's Natural Health Products Ingredients Database lists calcium silicate with non-medicinal purposes of absorbent, anticaking agent, bulking agent and opacifying agent.
Source: webprod.hc-sc.gc.ca (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
Calcium silicate suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking calcium silicate suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell calcium silicate? Request a listingFrequently asked questions
What forms of calcium silicate can brands buy?
Common forms include food grade, pharmaceutical grade and high-absorption carrier grades. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for calcium silicate include?
Expect identity, assay, loss on ignition and loss on drying, heavy metals and fluoride and absorption capacity and bulk density, each with its method, specification and result for that lot.
How should calcium silicate be stored?
Store sealed in lined bags in a dry area, away from humidity and strong odors, since the porous powder readily takes up both. It is chemically stable, so shelf life is mostly about moisture pickup; the supplier sets it, and older stock is retested for loss on drying and absorption capacity.
What is the regulatory status of calcium silicate?
21 CFR 172.410 permits calcium silicate as an anticaking agent in food at no more than 2 percent by weight of the food, or up to 5 percent by weight of baking powder. Health Canada's List of Permitted Anticaking Agents allows calcium silicate as an anticaking agent in baking powder at up to 5.0%. Health Canada's Natural Health Products Ingredients Database lists calcium silicate with non-medicinal purposes of absorbent, anticaking agent, bulking agent and opacifying agent.
More starches, carriers and excipients
- MaltodextrinMaltodextrin (CAS 9050-36-6) · Hydrolyzed starch
- Tapioca starchCassava starch · Manihot esculenta starch
- Corn starchMaize starch · Zea mays starch
- Potato starchSolanum tuberosum starch · Starch, potato
- Rice starchOryza sativa starch · Starch, rice
- Modified food starchFood starch-modified · Modified starch
- Pregelatinized starchStarch, pregelatinized · Pregelatinised starch
- Tapioca maltodextrinCassava maltodextrin · Maltodextrin from tapioca
- Magnesium stearateOctadecanoic acid, magnesium salt · Magnesium octadecanoate
- Stearic acidOctadecanoic acid · C18:0 fatty acid
- Silicon dioxideSilica · Colloidal silicon dioxide
- Microcrystalline celluloseMCC · Cellulose gel
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