BATCH LOT VARIABILITY IN PERMEATION THROUGH NITRILE GLOVES

Many factors should be considered in the selection of chemical protect ive clothing, but the majority of selections are based on manufacturer s' permeation data composed of average results for three replicates; u sually no information about variability is provided. ii was hypothesiz ed that variability across batch lots might be considerable, and that variability may be due to cure factors that may vary from one site to another within the same company. Glass transition temperature (T-g) ha s been demonstrated to be an indicator of cure, and so its relationshi p to permeation parameters was examined. Steady state permeation rate, breakthrough detection rime (BDT), cumulative permeation at 125 minut es (ASTM F1407), and T-g (ASTM E1356) were measured for two makes of n itrile gloves presumably in four batches. T-g was not related to any o f the permeation parameters even though batch-to-batch variability was statistically significant for all parameters except BDT. A comparison with recent ASTM round-robin results indicates that some of the varia bility may be due to the method; however, manufacturer quality control must be suspected as the major source of variability based on the res ults of this study.