Measuring Odor Threshold Using a Simplified Olfactory Measurement Method

Abstract

This study used the Simplified Olfactory Measurement Method to clarify the fundamental characteristics of substances with offensive odors present in human living environments and to measure the odor detection threshold of these substances, which have relatively high boiling points and high molecular weights. Results showed that propanoic acid was the highest in those substances, with an odor threshold of 49 ppb, and phenylacetic acid was the lowest in those substances, with an odor threshold of 2.4×10 -6 ppb. Although there was a gap between the Simplified Olfactory Measurement Method and the Triangle Odor Bag Method, the former still fell in the range of thresholds that can occur between panels. Furthermore, the threshold for the relationship between thresholds of straight-chain fatty acids and molecular carbon numbers gradually decreased for carbon numbers from three to five and increased again in six. That trend resembles the result of the Triangle Odor Bag Method.