The Influence of Two Barrier Creams on the Percutaneous Absorption of m-Xylene in Man

Human volunteers were exposed to m-xylene by the percutaneous route (both hands immersed into the solvent for 20 minutes). The total amount of unchanged m-xylene eliminated through the respiratory tract during and after exposure and the total quantity of m-methylhippuric acid eliminated in urine during the subsequent 24 hours were measured. The majority of absorbed m-xylene (86 to 98%) is eliminated as m-methylhippuric acid in urine. The results obtained on eight subjects who repeated the test twice indicate that under similar experimental conditions the quantity of m-xylene absorbed percutaneously by an individual may vary with time by a factor of 2 or less. The interindividual variability in the total amount of m-xylene absorbed through the skin is greater than the intraindividual variability. Among 13 subjects, the ratio between the highest and the lowest value is 6.2; the mean percutaneous absorption rate of m-xylene amounts to 2.45 microgram/cm2 x min. The application of a barrier cream containing 10% silicone did not significantly influence the rate of percutaneous absorpiton of m-xylene by 11 subjects. Preliminary results obtained of five volunteers suggest that the application of a cream containing glycerol, stearates and oleostearates was not more effective.