Introduction. In the process of production, storage and application of a new environmentally friendly hydrocarbon fuel – naphthyl, intended for use in the Soyuz and Angara family of launch vehicles, its ingress into the water of reservoirs is not excluded, which determines the mandatory assessment of the danger of its single contamination of this environmental object.

Material and methods. A sample of naphthyl rocket fuel (RG–1), CAS number 94114-58-6, with a specific density of d420 = 830.0 kg/m3 was used as an object of research. The brutta formula of naphthyl is CI2,79H24,52. It is a colorless (or slightly yellowish) oily liquid with a characteristic odor of petroleum products. It is practically insoluble in water.

Results. It was found that the ecotoxicant content in water in concentration 10.0 mg/l led to a change in its transparency, the appearance of color and odor of petroleum products. The indicated naphthyl concentration is determined as a threshold for organoleptic harmfulness. During the study of the effect of the toxicant on the general sanitary regime of reservoirs, in the absence of changes in the indicators of biochemical oxygen consumption, its negative effect on nitrification processes and saprophytic microflora was revealed. The threshold concentration of the substance according to the general sanitary indicator of harmfulness is 5.0 mg/l. With a single intragastric injection to male rats, the tested xenobiotic caused a significant increase in heart rate and a change in a number of hematological parameters. The threshold for a single general toxic effect of naphthyl is 20.0 g/kg.

Limitations. The identified features of naphthyl behavior must be taken into account when it once pollutes the water of reservoirs (in case of an emergency). However, the data obtained are insufficient to substantiate the hygienic standard of the compound in the water of water bodies.

Conclusion. The results of the experiments indicate that a single ingress of naphthyl into the water represents an ecological and toxicological hazard, registered according to three basic signs of harmfulness, which are taken into account when justifying its maximum permissible concentration in the water of reservoirs.

Compliance with ethical standards. The studies were performed in accordance with the requirements of proper laboratory practice.

Authors contribution:Maslennikov A.A. — research concept and design, analysis of results, writing text;Demidova S.A. — planning and execution of research;Svyatkina M.D. — statistical data processing;Novikova O.N., Erunova N.V., Kucherskoy S.A., Zemlyanoj A.V. — editing.All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

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

Acknowledgment. The study was conducted within the framework of the State Contract on the topic “Experimental studies on the justification of the maximum allowable concentrations (MAC) of naphthyl in the air of the working area, in the water of water bodies of economic and drinking and cultural and household water use, in the soil of populated areas and agricultural lands”.

Received: January 19, 2024 / Accepted: May 5, 2024 / Published: June 28, 2024