This book provides a homogeneous inventory of weighted and averaged human olfactory thresholds for hundreds of chemicals. Until now data on olfactory thresholds has not been standardized and different values have been scattered throughout the literature. The authors have gathered together threshold values and have used a systematic approach to standardization, collecting masses of data from a wide variety of sources to arrive at a standard threshold value for each chemical. A short explanation of the mathematical methods used by the authors is given, while the bulk of the book is taken up by the table of values. This is a comprehensive reference for scientists working in chemoreception, zoology, food science, government health regulation, and others for whom it is important to measure levels of air-borne chemicals.