1.1 This test method describes a procedure for sampling and analysis of volatile organic compounds (VOCs) in ambient, indoor, or workplace atmospheres. The test method is based on the collection of air samples in passivated stainless steel canisters. The VOCs are subsequently removed from the canisters, separated by gas chromatography, and measured by a mass spectrometric detector. This test method describes procedures for sampling into canisters to final pressures both above and below atmospheric pressure (respectively referred to as pressurized and subatmospheric pressure sampling).2 1.2 This test method is applicable to specific VOCs that have been tested and determined to be stable when stored in pressurized and subatmospheric pressure canisters. Numerous compounds, many of which are chlorinated VOCs, have been successfully tested for storage stability in pressurized canisters (1, 2).3 While not as extensive, documentation is currently also available demonstrating stability of VOCs in subatmospheric pressure canisters. 1.3 The organic compounds that have been successfully collected in pressurized canisters by this test method are listed in Table 1. These compounds have been successfully measured at the parts per billion by volume (ppbv) level. This test method is applicable to concentrations of VOC from the detection limit to 300 ppb by volume. Above this concentration samples require dilution with dry ultra high purity nitrogen or air. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Safety practices should be part of the user's SOP manual.