Audit materials containing Principal Organic Hazardous Constituents (POHCs) have been developed by Environmental Monitoring Systems Laboratory (RTP) for use by federal, state, and local agencies or their contractors to assess the accuracy of measurement methods used during RCRA trial burn tests. Audit materials are current available for 27 gaseous organics in five, six, seven, and nine component mixtures at parts-per-billion levels (7 to 10,000 ppb) in compressed gas cylinders in a balance gas of nitrogen. Stability studies indicate that all of the organics tested (with the exception of ethylene oxide and propylene oxide below 10 ppb levels) are stable enough to be used as reliable audit materials. Subsequent to completion of the stability studies, 89 performance audits have been conducted with the audit materials to assess the accuracy of the Volatile Organic Sampling Train (VOST) and bag measurement methods during or prior to RCRA trial burn tests. A summary of the audits conducted for each POHC and the measurement system audited is shown in a technical paper accepted for publication by JAPCA. The audit results obtained with audit gases during RCRA trial burn tests are generally within + or - 50% of the audit concentrations. (Copyright (c) 1988 APCA.)