Comparative evaluation of permeation testing of protective gloves to solvents: in vitro in permeation cells versus in vivo in guinea pigs.

Most current data on the protective effect of gloves against chemicals are obtained in vitro, using permeation cells. In vivo testing would give additional information on efficiency but is both expensive and time-consuming. It would therefore be valuable to know whether any definitive relationship exists between results obtained in vivo and in vitro. Gloves of natural rubber, butyl rubber and polyvinyl chloride (vinyl) were tested against 3 organic solvents, toluene, 1,1,1-trichloroethane and butanol, in vivo in guinea pigs and in vitro in permeation cells. Breakthrough times, absorption rates and steady state permeation rates were determined and compared on a relative basis. Some of the gloves that had a low degree of resistance to the test solvent in vitro nevertheless showed a rather good reducing capacity on the percutaneous absorption in vivo. However, for 2 gloves where no breakthrough was noted for butanol in vitro, permeation occurred at a degree lower than the minimum detection level. At this low concentration, the solvent was not absorbed through intact skin but through damaged skin. The breakthrough times for the 3 solvents corresponded well for the 2 test systems. The relative absorption rates and relative steady-state permeation rates varied considerably and no definitive relationship between the 2 sets of test results could be seen.