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Calcium alginate

Calcium alginate suppliers and sourcing guide

Calcium alginate is the calcium salt of alginic acid, a polysaccharide extracted from brown seaweeds such as Laminaria, Lessonia and Macrocystis. It is made by neutralizing purified alginic acid with a calcium source, or from sodium alginate by exchanging sodium for calcium. Unlike sodium alginate it does not dissolve in water, so it is bought as a powder for films, coatings, fillings and heat-stable gels.

See suppliersWhat to ask for on the COA
Also known as
E404 · Alginic acid calcium salt · Calcium polymannuronate
Facts checked
November 2026

Forms and grades of calcium alginate

Suppliers sell different products under the same name. Specify the one you need.

  • Powder

    Fine off-white powder, typically 60 to 200 mesh, used where an insoluble alginate is needed.

  • By seaweed source

    Grades from different brown seaweed species, which differ in their mannuronic to guluronic acid ratio and gel character.

  • Fiber or film grades

    Calcium alginate made as fibers or films for casings and coatings, sold mostly to processors.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Assay
Alginate content, calculated on a dry basis, per the FCC monograph method.
Calcium content
Calcium by titration or ICP, to confirm the salt form.
Loss on drying and ash
Moisture and residue on ignition.
Heavy metals
Lead, and often arsenic, cadmium and mercury, by ICP-MS or AAS against the supplier's specification or Food Chemicals Codex (FCC) limits.
Microbiology
Total plate count, yeast and mold, E. coli and Salmonella.
Particle size
Sieve analysis to confirm mesh grade.

Storage, lots and expiry

Storage and shelf life

Keep calcium alginate in sealed bags in a cool, dry store; the powder absorbs moisture and can cake. Shelf life is set by the supplier's specification, typically as a retest date, with retest of moisture and microbiology for older stock.

Lots and expiry dates

Seaweed source and particle size can vary between lots and change texture, so record both. Keep the supplier's species declaration on file if your customers ask about seaweed origin.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

  • 21 CFR 184.1187 affirms calcium alginate, the calcium salt of alginic acid from brown algae, as GRAS for use in food only within the specific limitations listed by food category.

    Source: ecfr.gov (opens in a new tab)

  • 7 CFR 205.605(b) lists alginates as synthetic substances allowed in processed products labeled organic or made with organic ingredients.

    Source: ecfr.gov (opens in a new tab)

  • Health Canada's List of Permitted Emulsifying, Gelling, Stabilizing or Thickening Agents includes calcium alginate, with beer among its permitted foods.

    Source: canada.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 alginate suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking calcium alginate 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.

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Frequently asked questions

What forms of calcium alginate can brands buy?

Common forms include powder, by seaweed source and fiber or film grades. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for calcium alginate include?

Expect assay, calcium content, loss on drying and ash, heavy metals, microbiology and particle size, each with its method, specification and result for that lot.

How should calcium alginate be stored?

Keep calcium alginate in sealed bags in a cool, dry store; the powder absorbs moisture and can cake. Shelf life is set by the supplier's specification, typically as a retest date, with retest of moisture and microbiology for older stock.

What is the regulatory status of calcium alginate?

21 CFR 184.1187 affirms calcium alginate, the calcium salt of alginic acid from brown algae, as GRAS for use in food only within the specific limitations listed by food category. 7 CFR 205.605(b) lists alginates as synthetic substances allowed in processed products labeled organic or made with organic ingredients. Health Canada's List of Permitted Emulsifying, Gelling, Stabilizing or Thickening Agents includes calcium alginate, with beer among its permitted foods.

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