Ecological and toxicological assessment of hazard of contamination of water bodies by the γ-polyoxymethylene

Introduction. In the process of production, storage and application of the representative of new components of solid rocket fuels – γ-polyoxymethylene, its ingress into the water of reservoirs is not excluded, which determines the mandatory assessment of the danger of its single contamination of this ecosystem. Material and methods. As an object of research, γ-polyoxymethylene (γ-POM, polyformaldehyde, acetal copolymer) was used – a mixture of dimethyl esters of polyoxymethylene glycols – a fine amorphous white powder, CAS registration number 66455-31-0. The empirical formula is CH3O(CH2O)nCH3 at n = 100–300. It is practically insoluble in water. Results. It was found that the ecotoxicant content in water at a concentration of 50.0 mg/l led to a change in its transparency. The indicated concentration of γ-POM was determined as a threshold for organoleptic harmfulness. In the course of studying 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 impact on nitrification processes and saprophytic microflora was revealed. The threshold concentration of the substance according to the general sanitary indicator of harmfulness is 3.5 mg/l. In experiments on laboratory animals, it was noted that a single intragastric administration of the tested xenobiotic in the form of a suspension in a 2.5% solution of aqueous starch caused a significant decrease in heart rate and a change in a number of hematological parameters. The threshold of a single general toxic effect of γ-POM is 90.0 mg/kg. Limitations of the study. The revealed features of the behavior of γ-polyoxymethylene 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 connection in the water of water bodies. Conclusion. The results of the performed experiments indicate that a single ingress of γ-polyoxymethylene into the water represents an ecological and toxicological hazard registered for all three basic signs of harmfulness, which is taken into account when justifying its maximum permissible concentration in the water of reservoirs.