abstract the leaf essential oil of chromolaena odorata l. (asteraceae) harvested in togo were steam-distilled and investigated for chemical composition (gc and gc-ms) and in vitro potential cytotoxic activity on human epidermic cell line hacat. the chemical composition showed that the main constituents of essential oil sample were respectively -caryophyllene (25.2 %), germacrene d (18.8 %), and linalool (7.9 %). the in vitro cytotoxicity bioassays on human cell line hacat did not revealed any toxicity of c. odorata essential oil up to 3000 l.ml-1. pure commercial -caryophyllene and germacrene d standards appeared almost non-toxic (ic50 >3000 l.ml-1), proving the major role played by the major components in the overall cell viability showed by the c. odorata oil sample tested in this work.