E509 – Calcium chloride - Food additives database

Safety grading GREEN – SAFE

E509 (calcium chloride) is graded GREEN – SAFE for the general population because it is a simple mineral salt that dissociates into calcium and chloride ions, both of which are normal components of the human diet and body fluids. Regulators in both the European Union and the United States allow its use in foods, typically under “quantum satis” or good manufacturing practice conditions. In practice, this means manufacturers should use the minimum amount needed to achieve the intended technological effect.

In the EU, calcium chloride is listed as an authorised food additive (E509) and is used mainly as a firming agent, stabiliser and anti-caking agent. In the US, calcium chloride is affirmed as GRAS (Generally Recognized as Safe) for multiple technical functions (including firming, anti-caking, antimicrobial, pH control and processing aid uses) when used in accordance with good manufacturing practice.

Independent toxicology reviews and chemical safety assessments describe calcium chloride as having low systemic toxicity by the oral route. Where adverse effects appear, they are usually linked to local irritation from concentrated solutions or very high doses, not from typical food-use levels. An OECD screening assessment cites a long-term rat feeding study reporting no adverse effects at 1,000–2,000 mg/kg body weight per day for 12 months, which is far above realistic dietary exposure from food additive use.

For real-world dietary exposure from food additive uses, the weight of evidence supports a low risk profile. The main practical concern is not chronic toxicity, but irritation if a person were to ingest highly concentrated calcium chloride products (for example, non-food desiccants or industrial-grade solutions), which is a different exposure scenario than normal food consumption.

People who must restrict calcium intake (for example, some patients with advanced kidney disease, hyperparathyroidism, or a history of calcium-containing kidney stones) should consider their total dietary calcium. E509 in foods is unlikely to be a dominant contributor, but it can add small amounts of calcium and chloride. As with many salts, very high intake may contribute to digestive discomfort in sensitive individuals.

Should You Avoid E509?

Most consumers do not need to avoid E509. It is typically present at low levels and used for specific functional purposes such as keeping canned vegetables crisp, improving cheese curd formation, or preventing clumping in dry mixes. If you have a medical reason to limit dietary calcium or chloride, treat E509 as a minor contributor and focus on your overall diet pattern, portion size, and total mineral intake.

Common Uses

Canned and bottled fruit/vegetables: firming agent to help retain texture and “snap”.
Pickles and fermented vegetables: improves crispness and supports processing stability.
Cheese making: restores calcium balance in pasteurised milk to improve coagulation and curd firmness.
Tofu and plant-based “cheese”: used as a coagulant or texture aid in some formulations.
Dry mixes and seasonings: anti-caking to keep powders free-flowing.
Potato-based snacks: used in some processes to reduce acrylamide formation during high-temperature cooking.
Beverages and brewing: mineral adjustment to influence stability, flavour perception and processing performance.

Common names / Synonyms

Calcium chloride
Calcium dichloride
CaCl₂
Calcium chloride dihydrate (CaCl₂·2H₂O)
Firming agent (functional class on labels)

What is it?

Calcium chloride is an inorganic salt made of calcium and chloride. In food, it is valued for its ability to provide “free” calcium ions that interact with proteins and plant cell-wall components. This is why E509 can help cheese curd form more reliably and why it is used to keep fruits and vegetables firm. It also binds water strongly (it is hygroscopic), which helps prevent clumping in dry powders and supports free-flowing texture.

Food-grade calcium chloride is commonly produced from naturally occurring brines or mineral deposits. A purified calcium chloride solution can be made by extracting brine, removing unwanted minerals through precipitation and filtration, and then concentrating the solution by evaporation. Depending on the final product, the concentrated solution may be sold as a liquid (for direct dosing in processing) or dried into pellets, flakes, or prills for easier handling.

Food-grade specifications also control contaminants (for example, heavy metals) and require compliance with recognised purity standards such as the Food Chemicals Codex. In practical terms, E509 is a controlled, purified mineral salt with predictable behaviour. Its taste is distinctly salty and slightly bitter at higher concentrations, so food formulators generally use it sparingly. From a safety perspective, the relevant difference is dose and concentration: typical food uses are low, while concentrated non-food products can be irritant or corrosive if swallowed.

Where it’s allowed (EU vs US)

EU: Authorised as food additive E509 in a range of food categories under Regulation (EC) No 1333/2008 (Annex II), with conditions that vary by category and often rely on quantum satis.

US: Affirmed as GRAS under 21 CFR 184.1193 for multiple technical functions, with use governed by good manufacturing practice.

E509 – Calcium chloride