Toxicity evaluation of trisodium nitrilotriacetate

Abstract

Trisodium nitrilotriacetate (Na 3NTA) has partially replaced sodium tripolyphosphate as a builder in liquid and granular detergent formulations. Safety data on Na 3NTA and various other salts of NTA, plus products containing varying levels of Na 3NTA, are presented. Parameters investigated in this series of tests include acute oral toxicity in rats, monkeys, and dogs; subacute oral toxicity in rats; emetic toxicity in dogs; intraperitoneal toxicity in mice; eye irritation in rabbits; subacute percutaneous toxicity in rabbits, and primary irritation and sensitization in rabbits and humans. Extremely high concentrations of Na 3NTA (7500 ppm or greater) incorporated into the diet of rats for a period of 90 days produced kidney lesions of varying severity. No other significant abnormalities were noted in the subacute oral toxicity studies. No unusual symptoms were noted in surviving animals after receiving acute oral or ip doses of the NTA salts or products containing Na 3NTA. LD50 values obtained from these studies show Na 3NTA to be only moderately toxic and that its addition to products does not increase their oral toxicity. Skin and eye irritation studies with products containing Na 3NTA showed the products to be similar to current market products. Moreover, no evidence was seen to indicate that sensitization occurred after multiple exposures of humans in a repeated insult patch test.