Polymer properties associated with chemical permeation performance of disposable nitrile rubber gloves

Abstract

Unlike other chemical protective clothing and devices, disposable gloves are not reliably certified to exceed chemical permeation performance standards. In light of generalized chemical compatibility charts, significant variability in performance exists between similar products on the market. This study evaluates whether nitrile rubber composition and uniformity are better associated with the observed product variability in chemical resistance than the available mechanical testing (e.g., tensile strength) done on these products. The independent variables evaluated include two physical, three mechanical, and four compositional parameters. Based on correlation and multiple regression analyses, the factors associated with variation in permeation of ethanol are area density, acrylonitrile content, carboxylation of the base polymer, the amount of extractable oils and oily plasticizers, and polymer uniformity. Increases in area density, acrylonitrile content, and carboxylation improve chemical resistance. Decreases in extractable oils and polymer variability (uniformity) also improve chemical resistance. On average, these combined factors accounted for about 53-67% of the observed variability in permeation, which were moderate but not strong associations. In contrast, tensile strength accounted for about 1% of the observed variability, a negligible effect. These results support the notion that standardized tests and certification criteria need to address polymer composition and uniformity to reduce gaps in performance. However, in light of the lack of strong correlations, further evaluation with tighter control over chemical composition is warranted.

Effect of multiple alcohol-based hand rub applications on the tensile properties of thirteen brands of medical exam nitrile and latex gloves

“…Differences of the ranges for tensile strengths and elongation were 2.7fold and 1.9-fold, respectively, larger than those for the latex gloves. These are similar with those reported by Phalen and Wong, [16] showing threefold (11-34 Mpa) and 2.5-fold (440-1100%) differences among 37 disposable nitrile gloves. Unlike the latex gloves, the upper tensile properties were not found from Brand F, which was the thickness glove model, nor the lower properties found from Brand L-thinnest glove model.…”

Disposable Nitrile Glove Resistance to Limonene: Dextrous Robot Hand Versus ASTM F739 Comparison

“…The negative r was because of our infrared measurements for A were suggestive that the glove maker increased A for the thinner gloves to try to compensate for decreasing thickness (Table ) and so is an artifact of glove design. The negative r is opposite to that expected since data in the literature support a direct linear relationship, that is, as A increases so too should SBT, other variables being constant but the thickness is not constant here. − This indicates that one-on-one linear regression results are not necessarily cause and effect if interactions are occurring that may be better described through multivariate analysis.…”

Review of the Performance, Selection, and Use of Gloves for Chemical Protection

“…Gloves made by different manufacturers, even different models and lots from the same manufacturer, may vary widely in performance due to differences in basic glove material, additives, thickness, and design. − Because of these variations, it is important to evaluate the performance of gloves being considered or in actual use by consulting trusted reference sources and, in critical situations, by obtaining or conducting performance testing on specific gloves against the chemical substances in use. Many glove manufacturers will provide chemical permeation and resistance data that can help ensure that a specific brand or model will perform to needed specifications.…”

“…These differences are attributable to various formulations and additives, thicknesses, and designs. For nitrile gloves, the amounts of acrylonitrile (CN), carboxylation (COOH), oily plasticizers (%), area density (g/cm 2 ), and thickness (mm) all play a potential role in chemical resistance. − Additional considerations must also be made for thicker, nondisposable chemical gloves designed for repeated use. Under the direction of the manufacturer, decontamination via solvent extraction, detergent washing, or thermal treatment may be necessary under certain circumstances.…”