What Is Sodium Aluminum Phosphate?

The FDA's Substances Added to Food inventory lists sodium aluminum phosphate, acidic or basic, with technical effects including anticaking agent, drying agent, emulsifier or emulsifier salt, humectant, leavening agent and texturizer, and cites 21 CFR 182.1781 and 182.90, in the part of FDA rules covering substances generally recognized as safe. The FDA's standard of identity for pasteurized process cheese lists sodium aluminum phosphate among the permitted emulsifying agents, with emulsifying agent solids limited to not more than 3 percent of the weight of the cheese.

The FDA's database of Select Committee on GRAS Substances reviews lists both acidic and basic sodium aluminum phosphate under a 1975 report with a Type 1 conclusion. The database defines a Type 1 conclusion as no evidence in the available information that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public at levels now current or that might reasonably be expected in the future.

In Europe, a 2018 European Food Safety Authority panel said sodium aluminium phosphate, acidic (E 541) is permitted in only a few specific products with exposure probably near zero, that aluminium compounds have low bioavailability and low acute toxicity with no concern for genotoxicity or carcinogenicity, and concluded it is of no safety concern in its current authorised uses and use levels.

For context, ATSDR says aluminum compounds may be added during food processing to products such as flour, baking powder, coloring agents and anticaking agents, and that an average adult in the United States eats about 7 to 9 mg of aluminum per day in food.