A Moving Robotic Hand System for Whole-Glove Permeation and Penetration: Captan and Nitrile Gloves

Abstract

The aim of this study was to develop a robotic hand to test the influence of hand movement on the permeation/penetration of captan through disposable nitrile rubber gloves. An available robotic hand was modified to within one standard deviation of the anthropometric 50th percentile male hand. Permeation tests used a nylon inspection glove interposed between medium-size outer and inner nitrile gloves, the latter protected the hand. Permeation of an aqueous emulsion (217 mg/mL) of captan was conducted at 35°C ± 0.7°C. A new surface wipe technique facilitated collection of captan from the inner surface of the exposed nitrile gloves, a technique favored above rinse methods that extracted captan from within the glove. With hand movement, the permeated mass of captan collected after 8 hr ranged from 1.6 to 970 μ g (Brand A) and 8.6 ± 1.2 μ g (Brand B). Without hand movement, the corresponding masses ranged from 1.4 to 8.4 μ g (Brand A) and 11 ± 3 μ g (Brand B). These results were not significantly different at p ≤ 0.05 using parametric and nonparametric statistical tests but indicated that hand movement could influence the precision of permeation (F-test p ≤ 0.05). One glove exhibited failure after 2 hr with movement, in comparison with 0.5 to 9.9 μ g captan with no movement. Hand movement did not appear to significantly affect the permeation of captan through nitrile gloves. However, hand movement did influence physical and/or chemical degradation, resulting in glove failures. The robotic hand simulated normal hand motions, was reliable, and could be used to assess the influence of hand movement on the permeation of nonvolatile components through gloves. Future research should continue to investigate the influence of hand movement and additional work factors on the permeation, penetration, and physical integrity of protective gloves.

Keywords:

• penetration
• permeation
• pesticide
• protective clothing
• surface sampling

ACKNOWLEDGMENTS

The authors are grateful for grants provided by NIOSH Southern California Education and Research Center (ERC), NORA; Association of Schools of Public Health/NIOSH/CDCP; and CDCP/NIOSH. Thanks go to Steven Phalen for his expertise in electronics.

Notes

^A Samples conditioned overnight at 55% ± 1% relative humidity and measured using a digital micrometer screw gauge. The sample size for each glove was n = 60.

^A Source for anthropometric 50th percentile male hand.^{( 23 )}

^B Data for anthropometric 50th percentile male hand was not provided. Values were interpolated from provided ratios for the 1st percentile female and 99th percentile male.^{( 23 )} Results using provided ratios at either extreme were not significantly different at p ≤ 0.05.

^A Voltage direct current supplied by a universal A/C power adapter.

^B Closing grip strength measured using a Jamar hydraulic hand dynamometer (n = 3).

^C Hand did not close fully at 1.5 VDC.

^A Modified Yaeger Robotic hand with an open/close cycle of 20 sec at 35°C ± 0.7°C for 8 hr.

^B Modified Yaeger Robotic hand with flat-hand posture and no movement at 35°C ± 0.7°C for 8 hr.

^C Extracted with 30 mL hexane at 50°C and ultrasonication for 1 hr.

^D Combined perfluorohexane-gauze wipes extracted with 10 mL hexane at 50°C and ultrasonication for 1 hr.

^E Excluding tests 4 and 7 (indicators of penetration) the nylon glove was 2.4 ± 1.6 μ g, and the combined total was 3.8 ± 1.9 μ g captan, which were not significantly different (p ≤ 0.05) from the no movement tests.

^F The nylon and outer glove test data were combined prior to calculating the mean and standard deviation.

^A Modified Yaeger Robotic hand with an open/close cycle of 20 sec at 35°C ± 0.7°C for 8 hr.

^B Modified Yaeger Robotic hand with flat-hand posture and no movement at 35°C ± 0.7°C for 8 hr.

^C Extracted with 30 mL hexane at 50°C and ultrasonication for 1 hr.

^D Combined perfluorohexane-gauze wipes extracted with 10 mL hexane at 50°C and ultrasonication for 1 hr.

^E The nylon and outer glove test data were combined prior to calculating the mean and standard deviation.

^A Modified Yaeger Robotic hand with an open/close cycle of 20 sec at 35°C ± 0.7°C for 2 hr.

^B Modified Yaeger Robotic hand with flat-hand posture and no movement at 35°C ± 0.7°C for 2 hr.

^C Extracted with 30 mL hexane at 50°C and ultrasonication for 1 hr.

^D Combined perfluorohexane-gauze wipes extracted with 10 mL hexane at 50°C and ultrasonication for 1 hr.

^E Catastrophic glove failure characterized by visual saturation of middle nylon collection glove and visual detection of holes by postexposure water-leak test.

^F The test data were combined prior to calculating the mean and standard deviation.