Degradation of Commercial Formulations of Mancozeb During Storage Under Subtropical Conditions

Three different commercial preparations of ethylenebisdithiocarbamates (EBDCs) were studies for the ethylertethiourea (ETU) present or formed in storage. In all the preparations lesser amounts of active ingredients than those mentioned on the packages were found. They contained 230 to 305 μg ETU/g of the preparation When opened. Storage of dithane M-45 for a period of 390 days showed a decline in the active ingredient, which was more pronounced when the packages were left open as compared to the closed packages. Varying amounts of ETU were observed during the entire period in both conditions of storage. Other degradation products present in all the formulations were identified as ethylenethiouram monosulfide (ETM), ethylenethiouram disulfide (ETD), ethyleneurea (EU), sulfur and 2-imidazoline.