Permeation of a 2,4-D isooctyl ester formulation through neoprene, nitrile, and tyvek protection materials.
Am Ind Hyg Assoc J 1989 Aug; 50(8):438-446
An investigation was made to assess the permeation of Esteron-99, a commercial herbicide formulation containing 65.4 percent of the isooctyl-ester of (2,4-dichlorophenoxy)acetic-acid (94757) (2,4-D- isooctyl-ester) and 34.6 percent of inert ingredients, on different types of materials. Commercially available neoprene and nitrile gloves and Tyvek clothing material were examined to determine the kinetic characteristics of permeation under field simulating conditions; to establish the role of the inert material and surfactants in the formulation and of the carrier on permeation kinetics; and to determine if the use of manufacturers' data on degradation of a protective material would allow the prediction of permeation behavior. Both the formulation concentrate and the highest recommended field spraying concentration of aqueous formulation, a 1:7 dilution, were used as challenge conditions. The glove materials tested included unsupported lined (US/L), unsupported unlined (US/UL), and supported lined. Both the US/L and US/UL neoprene gloves performed worse in the 8 hour screening study than the US/UL and US/L nitrile gloves. All gloves showed permeation by a mixed penetration/permeation mechanism. A cosolvent effect was indicated in that materials that allowed the greatest amount of the 2,4-D-isooctyl-ester to cross through also allowed other constituents to be detected before the ester itself. Neoprene was found to be the worst glove material in kinetic swelling tests with swelling occurring during both the formulation and aqueous challenges. The characteristics of surrogate single chemicals given in the literature of a glove manufacturer, in addition to the characteristics of the carrier and inert ingredients, were found sufficient to predict correctly the better protection properties of nitrile over neoprene. The authors conclude, however, that such prediction of protection properties must be confirmed by experiment.
NIOSH-Publication; NIOSH-Grant; Training; Chlorophenoxy-herbicides; Protective-clothing; Protective-materials; Hand-protection; Body-protection; Esters; Synthetic-rubbers; Chemical-kinetics; Materials-testing
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American Industrial Hygiene Association Journal
University of Cincinnati, Cincinnati, Ohio