Development of methodological approaches to the determination of safe levels of activity of harmful substances in the air of the working environment.

1. An experiment study was carried out to substantiate fundamental approaches to the determination of shift-average and maximum instantaneous concentration of highly cumulative substances in the air of the working environment. 2. The determination of maximum instantaneous concentrations in the air of the working environment is maintained for some groups of chemical compounds (irritant poisons, substances having acute effect, etc). An express, method of determining MAC in the air of the working environment has been developed for the purpose of hygienic norm-setting for irritant substances.