Permeation of captan through disposable nitrile glove

Abstract

The purpose of this study was to investigate the permeation of an aqueous emulsion of the pesticide, captan, as a wettable powder (48.9% captan) through a disposable nitrile glove material using an American Society for Testing and Materials (ASTM)-type I-PTC-600 permeation cell. The goal was to investigate the protective capability of the gloves against dermatitis. The analytical method was based on gas chromatography–mass spectrometry (GC–MS) and gas chromatography–electron capture detection (GC–ECD). The least quantifiable limit (LQL) was 6 ng for GC–ECD and 30 ng for GC–MS. Testing was conducted using the ASTM F739 closed-loop permeation method and a worst-case aqueous concentration 217 mg/ml of captan 50-WP. The average permeation rates were low, with 12±5 ng/(cm 2 min) after 2 h, 50±25 ng/(cm 2 min) after 4 h, and 77±58 ng/(cm 2 min) after 8 h. The calculated diffusion coefficient was (1.28±0.10)×10 −5 cm 2/h. No significant swelling or shrinkage occurred at P≤0.05. Infrared (IR) reflectance analysis of pre- and post-exposure glove surfaces confirmed no outer or inner surface degradation. The disposable nitrile glove showed excellent resistance to a highly concentrated aqueous emulsion of captan. Because the ASTM normalized breakthrough detection time of 250 ng/cm 2 was <2 h, these gloves should not be reused once worn, and decontamination is not advised. Protection is also advised for agricultural reentry field workers, because captan has been shown to persist on crops with a half-life greater than the current reentry intervals of 1–4 days.