Comparison of PH3 concentrations in perforated and nonperforated steel drums showed that it was possible to verify applied dosages of PH3 by intercepts obtained from regressions of log10 of gas concentrations on time. Analysis of data on gas concentration in grain that was fumigated in concrete bins for commercial purposes showed that there is close agreement between calculated dosages and actual amounts applied. A high correlation coefficient was obtained for steel drums and filled, and partly filled concrete elevator bins (r=-0.87 to -0.99) when gas concentration data were transformed to log10 scale and correlated to time.