Improvement of interlaboratory evaluation method of olfactometry in Japan

Odor measurement is a crucial element of odor management and regulation. In Japan, nationwide interlaboratory evaluation of olfactometry using a variety of test odorants started in 2002. In the interlaboratory tests, odor index, a sensory index of odor determined by the triangular odor bag method, is measured. In 2016, interlaboratory evaluation method of olfactometry was improved. Isoamyl acetate with a concentration of 50 ppm was used as a test odor, and a total of 128 olfactometry laboratories participated in the test. In this method, test results of 11 ‘excellent qualified laboratories’ designated by the Japan Association on Odor Environment (JAOE) were used to determine reference value and repeatability and reproducibility standard deviations of odor index. On the bases of these statistical values, measurement results of each laboratory were evaluated, including trueness and precision. Among 127 evaluated laboratories, 87 laboratories (68%) conformed to both trueness and precision criteria. In the case of ‘qualified odor measurement laboratories’ designated by the JAOE, 53 out of 68 laboratories (78%) conformed to both criteria. The qualified odor measurement laboratories registration system of the JAOE contributes to the improvement of the quality of olfactometry laboratories and the reliability of odor measurement in Japan.