The lack of information about agricultural chemicals on cotton lint and in air samples presented a challenge out of concern to the health of gin and textile workers. A method of analysis for the defoliant DEF (S,S,S, tributyl phosphorotrithioate) was developed for environmental levels. DEF was found on the lint tested at 1 1.5 µg. Respirable dust as measured by the vertical elutriator indicated 2.8 µg/m³ and with heavy lint and fly contamination, the Hi-Vol levels were 0.13 µg/m³.