In an approximate lethal concentration (ALC) study, three groups of six male rats each were exposed nose-only for four hours to vapor concentrations of 0.77, 2.5, at 3.1 mgfL of the test substance in air. No deaths or reportable clinical signs of toxicity were observed in rats exposed to vapors of the test substance in air. In the same study, two additional groups of six male rats each were similarly exposed for four hours to a combined vapor/aerosol concentration of 3.9 or 5.4 mg/L of the test material in air. Fractional mortalities at both exposure concentrations were 3/6. During the vapar/aerosol exposures, mts displayed no alerting response. Rats in the 39 ag/L exposure group displayed head bobbing, splayed legs, and slight palpebral closure. The rats that displayed these clinical signs died during the 14-day post-exposure observation pedod. The rats that died in the 5.4 mg/L exposure group displayed weakness, lethargy, abnormal gait, and irregular respiration.