Allyl isothiocyanate (AITC) is a natural occurring essential oil found in plants of the family Brassicaceae. It is a well-recognized antimicrobial agent against a variety of foodborne pathogens. By vapor and solution deposition methods into raw and de-oiled Laminaria japonica, an edible, brown seaweed, we demonstrate AITC vapor phase activity against Listeria monocytogenes, Bacillus subtilis, and Micrococcus luteus. Colony deactivation occurred for each bacterium in the range 99.87–99.99% within 72 h. The kinetics of these activities was fitted to the Weibull and the Albert-Mafart population decay models. Combined standard uncertainty in the final model fitting is introduced for these models, along with bias factor analysis. The former indicates the degree of fit of the models while the latter indicated which of the models was the most appropriate. In general, the bias factor analysis of the models indicated that the Albert-Mafart model was the superior. The continued activity of AITC after contact with the seaweed delivery system suggested that the L. japonica + AITC system would represent a viable natural, edible system for food preservation.