The 50% oral convulsive dose (C.D.50) of chlorphenoxamine (β-dimethylaminoethyl p-chloro-α-methylbenzhydryl ether hydrochloride) (I) in mice was 315 mg./kg., and the L.D.50 value was 575 mg./kg.Comparable values for Keithon (the β-diethyl analog of I) were 470 and 650 mg./kg., resp.The intravenous L.D.50 value of I in dogs was 30.8 mg./kg.Incorporation of 0.166, 0.249, or 0.374% of I in the diet of rats for 26 weeks was without effects attributable to I.When I was fed to dogs daily at 10 mg./kg. for 18 weeks, then for an addnl. 29 weeks at 30 mg./kg. a loss of body weight was noted, and initially an occasional emetic response was seen.No other effects of the drug were noted.