ESTIMATING SERVICE LIVES OF ORGANIC VAPOR CARTRIDGES

Procedures were developed for estimating service lives of air-purifyin g organic vapor respirator cartridges, including methods for untested compounds and use conditions (concentration, temperature, and airflow rate). Correlations of adsorption capacities and adsorption-rate coeff icients based on equilibrium and breakthrough curve data were reviewed . These correlations were combined using the Reaction Kinetic (modifie d Wheeler) equation to estimate breakthrough times. The proposed estim ation procedure showed 95% confidence intervals of up to +/- 50% when no breakthrough data were assumed. It is shown how even limited breakt hrough curve data for one vapor/carbon combination can be used to subs tantially improve accuracy of the estimation. Only dry conditions (bel ow 50% relative humidity) have been considered so far.