Decontamination of pesticide contaminated fabrics by laundering

The overall objective of this research was to contribute to the development of functionally designed protective clothing by investigating the launderability of fabrics contaminated with pesticides and to determine if the variables; water temperature, storage and exposure to weather, affect pesticide removal. Fabric selection enabled the comparison of two fabrics commonly worn by the pesticide applicator, 100% cotton, denim and chambray, and alternative fabrics, Gore Tex® and Tyvek®, that have been shown to provide greater protection against pesticide penetration. Two pesticide chemicals: Captan®, a chlorinated hydrocarbon, and Guthion®, an organophosphate, were used in this research.

A pesticide spray system was used to expose fabric samples to pesticide solutions and pretreatment levels of contamination were determined. The laundry procedure utilized a launder-ometer at wash temperatures of 38, 49 and 60°C in a one-laundry cycle adaptation. The storage treatment subjected contaminated fabrics to a simulated home laundry storage condition at intervals of 4 and 7 days. The exposure to weather treatment utilized a weather-ometer to simulate outdoor exposure conditions.

The initial amount of pesticide residues contaminating the fabric samples averaged 9.3 µg/cm² which is representative of the mean deposition found on the applicators, clothing during a field spraying study. The effect of storage treatment on the initial level of pesticide residues showed a decrease in the level of contamination; in comparison, the effect of treatment weather resulted in virtually no change in the level of pesticide residues on contaminated fabrics.

Differences in decontamination, i.e., removing pesticide residues by laundering, were dependent on pesticide chemical, water temperature and fabrics. Overall, the laundry process removed a greater percentage of Captan® residues from the fabrics when compared to Guthion® residue removal, and an increase in temperature resulted in an increase in pesticide removal. There was a significant difference in removal among fabrics; Captan® residues were more difficult to remove from denim and Guthion7reg; residues were more difficult to remove from Gore Tex®.

The effect of storage treatment prior to laundering resulted in an increase in the percentage of pesticide residues removed. In comparison, exposure to weathering prior to laundering exhibited a decrease in pesticide removal.