What is Calcium Hydroxide?
Calcium hydroxide (CAS Number: 1305-62-0) is an inorganic compound produced by treating calcium oxide (quicklime) with water. Also known as slaked lime or hydrated lime, it appears as a white powder or colorless crystal. In food applications, it is used in its food-grade form, which meets strict purity and contaminant specifications established by regulatory agencies.
Common Uses
Calcium hydroxide serves multiple functions in food manufacturing. As a firming agent, it is commonly used in the production of pickled vegetables, canned vegetables, and processed fruits to maintain texture and crispness by cross-linking pectin in cell walls. It is particularly prevalent in the processing of corn for nixtamalization—a traditional process that improves nutritional availability and safety of corn-based products.
The additive functions as a pH control agent, helping manufacturers maintain optimal acidity levels in various food products including beverages, baked goods, and condiments. As a nutrient supplement, calcium hydroxide provides bioavailable calcium, supporting the nutritional profile of fortified foods and beverages. It is also used as a processing aid in various manufacturing stages where pH adjustment or mineral supplementation is required.
Safety Assessment
Calcium hydroxide has an extensive history of safe use in food production. The FDA has designated it as Generally Recognized as Safe (GRAS), meaning it is approved for use in food without requiring pre-market approval. This determination is based on a long history of safe use and scientific evidence demonstrating its safety at levels used in food manufacturing.
According to FDA records, there have been zero reported adverse events associated with calcium hydroxide as a food additive, and zero recalls have been issued related to its use in food products. The additive's safety profile is further supported by its use in traditional food processes spanning centuries, particularly in nixtamalization practices used in Latin American and other cuisines.
The European Food Safety Authority (EFSA) also recognizes calcium hydroxide as a safe additive and has established acceptable daily intake levels. Toxicological studies have shown that calcium hydroxide, when used in food manufacturing at appropriate levels, does not pose health risks to consumers.
Regulatory Status
In the United States, calcium hydroxide is approved as a direct food additive and is listed in Title 21 of the Code of Federal Regulations (CFR). It is approved for use in multiple food categories without quantitative limitations when used in accordance with good manufacturing practices.
Internationally, calcium hydroxide is accepted as a food additive in the European Union, Canada, Australia, and numerous other countries. It is listed in the FAO/WHO Codex Alimentarius as an approved food additive, reflecting broad international recognition of its safety and utility.
Key Studies
Scientific literature on calcium hydroxide in food applications supports its safety profile. Research on nixtamalization demonstrates that calcium hydroxide not only improves the nutritional bioavailability of minerals in corn but also enhances food safety by reducing mycotoxin levels. Studies on its use as a firming agent confirm its effectiveness in maintaining product texture without evidence of adverse health effects at typical usage levels.
Long-term consumption studies in populations with high dietary exposure to calcium hydroxide-processed foods (such as in traditional corn-consuming cultures) have not identified adverse health outcomes attributable to the additive itself. Acute toxicity studies demonstrate that calcium hydroxide has low toxicity when ingested at levels far exceeding those present in food products.