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Project Status: complete

Title: Perception of hydrogen sulfide odor in relation to setting an ambient standard.

Principal Investigator / Author(s): Amoore, John E.

Contract Number: A4-046-33

Research Program Area: Atmospheric Processes


This is a review of the scientific literature relating to the odor of hydrogen sulfide. There have been 26 published reports on the detection threshold concentration, of which the median is 0.008 parts per million, by volume, of hydrogen sulfide. Among a group of 100 healthy, normal observers, there is likely to be a 250-fold range of odor sensitivities. The perceived intensity of the odor sensation increases by a factor of 1.2 for each doubling of the hydrogen sulfide concentration. Evaluation of odor recognizability, unpleasantness and annoyance, have been reported in five publications. Factors responsible for annoyance can be categorized as the unpleasant odor sensation itself, its effects on social life, and the instigation of headache or nausea. As a provisional rule, it appears that when an unpleasant odor reaches about five times its detection threshold concentration, then this is the median threshold for odor annoyance. The present ambient air quality standard for California is 0.03 ppm for hydrogen sulfide, averaged over one hour. At this concentration, it may be estimated that 83% of people are able to detect the odor and 40% will experience odor annoyance.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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