Development of a database for sensory irritants and its use in establishing occupational exposure limits

A database was developed for chemicals whose sensory-irritating properties had been investigated using a previously described animal bioassay. In this bioassay, mice were exposed to an airborne chemical, and changes in their respiratory pattern were determined. For each chemical tested, the concentration capable of producing a 50% decrease in respiratory rate (RD50) was obtained and its relative potency estimated. For the current study, 295 such airborne materials, including single chemicals and mixtures, were found in the literature. A total of 154 RD50 values were obtained in male mice of various strains for the 89 chemicals in the database for which there were also TLVs. An examination of the TLVs and RD50 values demonstrated, as previously with the smaller dataset (n = 40), a high correlation (R2 = 0.78) of the TLVs with 0.03 x RD50. This supports the continued use of the animal bioassay for establishing exposure limits to prevent sensory irritation in the workplace. No other bioassay provides this type of information or has been used so extensively to suggest guidelines for occupational exposures.