The results of an evaluation of substitute organic vapor cartridge test agents, to replace the possibly carcinogenic carbon- tetrachloride (56235), for use in evaluations of chin style canisters were reported. Based on a previous study examining replacement agents for nonpowered organic vapor cartridges, four possible replacement agents, ethyl-acetate (141786), pentane (109660), n-hexane (110543), and heptane (142825), were evaluated. These agents were tested on respirator cartridges and compared with results obtained using carbon-tetrachloride at test humidities of 50% and 80% and a temperature of 25 degrees-C. Due to its water solubility, ethyl-acetate was eliminated as a possible replacement agent. Evaluation of initial test data indicated that 4,000 parts per million (ppm) pentane was the best candidate for direct comparison with 5,000ppm carbon-tetrachloride. Comparable breakthrough times were seen for 4,000ppm pentane and 5,000ppm carbon-tetrachloride. Further analyses including a correlation study, linear regression analysis comparison, and a reproducibility study indicated that pentane was a suitable replacement for carbon- tetrachloride for testing of chin style canisters.