The use of a thermal plasma afterburner in hazardous waste incineration could prevent the formation of toxic organochlorine pollutants. The present work demonstrated cost-optimal adaptive operation of a laboratory model system composed of an induction plasma jet with optical emission diagnostic tools. Input settings (plasma power and oxygen content) were continually adjusted in response to on-line spectroscopic analysis of the product gas. This adaptive strategy allowed cost-effective destruction of organic contaminants under a variable feed load. The system was able to reach and maintain a target level of destruction efficiency using optimal combinations of input settings.