The Odor Threshold of Phosphine

In the literature for odor threshold, values of phosphine are given which vary between 3 ppm^1,2 and 0.02 ppm.³ According to another paper phosphine is odorless even in concentrations up to 200 ppm.⁴ Since phosphine prepared from metal phosphides is used as a fumigant for foods, feeds, and processed food products, we carried out new investigations to clarify the discrepancy.