Assessment of the toxicity and hazard of a chelating agent based on a mixture of di- and triammonium salts of nitrilotriacetic acid in water and atmospheric air

Introduction. The article evaluates the toxicity and danger of a chelating agent based on a mixture of di- and triammonium salts of nitrilotriacetic acid.

The relevance of the study is related to the assessment of the impact of this substance on water and atmospheric air, especially in the context of its use in oil production and potential release into the environment and impact on humans.

Material and methods. The studies included assessing the effect of the substance on the organoleptic characteristics of water, the process of self-purification of water bodies, as well as conducting acute and subacute toxicological tests to study the effect of the mixture on the body of warm-blooded animals.

Results. For a mixture of di- and triammonium salts of nitrilotriacetic acid, a value of 70 mg/l is recommended as the threshold concentration for the organoleptic indicator, the limiting indicator is odor. The mixture does not affect the processes of self-purification of water in water bodies at the maximum studied concentration. Toxicological studies have shown that the mixture is classified in the 3^rd hazard class (LD₅₀ 2250±250 mg/kg) and has a high degree of accumulation. In addition, it has a moderate irritant effect on the mucous membrane of the eye and intact skin upon repeated application, and does not have a skin-resorptive effect. After prolonged exposure, the mixture affects the blood parameters of animals, as well as the functional state of the liver and kidneys.

Limitations. The studies were carried out in accordance with the requirements of Methodological instructions 2.1.5.720–98 and Methodological instructions 2630–82. The research results are applicable in substantiating hygienic standards in the water of water bodies and atmospheric air.

Conclusion. Thus, based on literature data, as well as our own research, for a mixture of di- and triamonium salts of nitrilotriacetic acid, we can recommend a value of 0.8 mg/l as the approximate permissible level in the water of water bodies (hazard indicator — sanitary-toxicological, hazard class — 2), and a value of 0.1 mg/m³ as the tentative safe exposure level in the atmospheric air of populated areas.

Compliance with ethical standards. The study was carried out in accordance with generally accepted rules for the ethical treatment of laboratory animals and was approved by the Bioethical Commission of the Federal State Budgetary Institution “Scientific Research Institute of Human Ecology and the Environment named after A.N. Sysin” of the Ministry of Healthcare of the Russian Federation 06.02.2017.

Authors contribution. All co-authors made an equal contribution to the research and preparation of the article for publication.

Conflict of interests. The authors declare no conflict of interest.

Funding. The study had no sponsorship.

Accepted: May 23, 2023 / Revised: August 22, 2024 / Received: September 20, 2024 / Published: October 30, 2024