E545 - Polyphosphate d'ammonium

Origin

Ammonium polyphosphate (APP) is an inorganic salt of polyphosphoric acid and ammonia. It is not naturally occurring and is synthetically produced. The degree of polymerization (n) is variable and can be quite high, leading to polymeric or oligomeric forms. Commercial APP is typically a mixture of various chain lengths. It is synthesized by reacting phosphoric acid with ammonia under controlled conditions.

Usage

Ammonium polyphosphate is primarily used as a flame retardant. It finds applications in various materials, including plastics, coatings, and textiles. When exposed to heat, APP decomposes to produce phosphoric acid, which promotes char formation on the surface of the material. This char layer acts as an insulator, slowing down the combustion process and reducing the release of flammable gases. In food applications, it has been investigated as a potential additive but is not widely approved or used due to concerns regarding phosphate levels and potential for ammonia release. Its use in food is very limited and often disallowed.

Side Effects

While APP is considered relatively safe in its primary industrial applications, its potential use in food raises concerns. High levels of phosphate intake can disrupt calcium metabolism and potentially lead to kidney problems, particularly in individuals with pre-existing renal conditions. The release of ammonia during decomposition could also pose a risk, although this is generally minimal under normal usage conditions. There is no established Acceptable Daily Intake (ADI) for APP as a food additive due to its limited use and regulatory status. Studies on the toxicity of APP are limited, and more research would be needed to fully assess its safety profile for food applications.

Regulatory Status

Ammonium polyphosphate is not widely approved as a direct food additive. Its use is primarily regulated in the context of flame retardants for materials that may come into contact with food. Regulations vary by country and region. In the EU, its use as a direct food additive is not permitted under current regulations. The FDA in the United States has not approved APP for direct addition to food. Always consult local regulations before considering the use of APP in any food-related application.