Cotton dust 1182 DB has been treated with several solvent systems to reduce endotoxin levels. Although these treatments were designed to eliminate the biological activity of endotoxins, they could also extract or degrade other bioactive chemical constituents of cotton dust. Condensed tannins and amines are two plant components which can show biological activity. The effect of several treatments on levels of condensed tannins was compared based on hydrolysis of treated and untreated dust in 95:5 butanol:HC1. Amine content of treated and untreated dust was compared by reaction of dust extracts with ninhydrin.