Citrate

Abstract

Because of its performance, safety and biodegradability, citrate is the prime example of an environmentally acceptable detergent builder. Citrate is widely used in heavy-duty liquid laundry detergents, usually in the form of the neutral sodium salt, where it exhibits good water hardness sequestration performance and excellent solubility and compatibility characteristics. Citrate is ubiquitous in nature; it is a natural constituent and common metabolite of many plants and animals, appearing in small amounts in most organisms and in natural waters and soil. It is commercially produced by microbial fermentation processes. Food-grade forms of citric acid and its sodium, potassium and calcium salts are "generally recognized as safe" for use in foods. Citrate has been shown to be safe for a variety of organisms at levels much greater than would be expected to be added to the environment from many commercial uses including detergents. The rapid biodegradation of citrate in solution under natural conditions and in sewage treatment processes has been demonstrated.