RD50 value as the criterion for setting maximum admissible levels of occupational exposure to irritants in Poland.

The aim of this work is to analyse Maximum Admissible Concentration (MAC) values proposed for irritants by the Group of Experts for Chemical Agents in Poland, based on the RD50 value. In 1994-2004, MAC values for irritants based on the RD50 value were set for 17 chemicals. For the purpose of the analysis, 1/10 RD50, 1/100 RD50 and the MAC/RD50 ratio were calculated. The determined MAC values are within the 0.01-0.09 RD50 range. The RD50 value is a good rough criterion to set MAC values for irritants and it makes it possible to estimate quickly admissible exposure levels. It has become clear that, in some cases, simple setting the MAC value for an irritant at the level of 0.03 RD50 may be insufficient to determine precisely the possible hazard to workers' health. Other available toxicological data, such as NOAEL (No-Observed-Adverse-Effect Level) and LOAEL (Lowest-Observed-Adverse-Effect Level), should always be considered as well.