The report discusses: the development of EPA's Hazardous Air Pollutants Mobile Laboratory (HAPML), equipped with monitors for on-line analysis of inorganic and organic stack gas emissions and instrumentation including a gas chromatograph and mass spectrometer (GC/MS); results from the first field test and other combustion sources; and plans for the future. The EPA has increasingly viewed incineration as an effective means of destroying hazardous waste. Incinerators are permitted--via a detailed trial burn under the Resource Conservation and Recovery Act--to burn hazardous waste. These incinerators are then operated using CO and other process parameters established during the trial burn to determine compliance. Because of the interest in monitoring the performance of incinerators on a real-time basis and the need to characterize emissions from a variety of incinerators, the EPA built the HAPML for real-time and near real-time monitoring of hazardous waste incinerator emissions and operating parameters.