Gas samples taken off in animal waste utilization plants in summer, autumn and winter 2008/2009 were analyzed by gas chromatog. and treated with low-temperature plasma in air in a lab. test stand at 33.1 degrees C (active power 15-65 W, energy d. 2-8 Wh/m(3), gas flow rate 0.28 m/s). Eighteen chem. mostly malodorous compds. (chlorinated aliph. and arom. hydrocarbons, AcNMe(2), alkylamines, phenol, benzoquinone, Me(2)S(3), alkyl phthalates, PrSH) were identified in the inlet gas samples. The plasma discharge resulted in formation of O(3). Its concn. showed a max. when plotted against the power input Good decompn. and removal of the gas sample-contained org. compds was achieved for benzoquinone and AcNMe(2) where an increase in concn. was obsd. or for CCl(2)=CHCl and phenol where the removal degree was lower than 50%.