Practical approaches to the application of hygienic criteria for substances that do not need to establish hygienic standards in the air of the working area

Introduction. When new industrial enterprises appear, whose activities are related to the use and/or production of chemicals, pollutants that do not have approved hygiene standards may appear in the air of the working area. We note that the introduction of new chemicals into the production process does not always require the development of a hygienic standard in the air of the working area, since conditions can be met for these compounds, namely compliance with hygienic criteria, under which the development and approval of hygienic standards is not required. The study aims to demonstrate a practical approach to the application of hygienic criteria for substances that do not need to establish hygienic standards in the air of the working area on the example of paraformaldehyde. Materials and methods. The theoretical basis of the work was the methods of substantiating the need to develop hygienic standards: maximum permissible concentration (MPC) and approximate safe level of exposure (ASLE) to harmful substances in the air of the working area. The practical basis of the work was methodological guidelines for measuring mass concentrations of formaldehyde in the air of the working area by a photometric method based on the reaction of formaldehyde with acetylacetone in an ammonium acetic acid medium and subsequent photometric measurement of the optical density of the yellow-colored reaction product. Results. The conducted experiment simulating the processes of formaldehyde emission from paraformaldehyde in various production conditions showed that paraformaldehyde under the influence of temperature releases formaldehyde, while the rate of formaldehyde release increases with increasing temperature. Conclusion. Analysis of the technology of production (application) of paraformaldehyde, toxicological data, as well as an experiment modeling the processes of formaldehyde emission from paraformaldehyde in various production conditions allows us to conclude that the development of a hygienic standard for paraformaldehyde in the air of the working area is impractical, according to paragraph 2.1.1. GN 1.1.701-98 "For substances containing the ingress of which into the air of the working area in the form of vapors and aerosols or a mixture thereof is excluded due to the physico-chemical properties, as well as production and application conditions" and p.2.1.3. GN 1.1.701-98 "For substances that easily hydrolyze in the air with the formation of hydrolysis products, the toxicity of which has been studied and the hygienic standards of which have been established".