Some Chemicals Requiring Special Consideration when Deciding Whether to Sample the Particle, Vapor, or Both Phases of an Atmosphere

Abstract

Abstract When preparing to measure the concentration of a contaminant in air, a decision must be made whether to sample the particle phase, the vapor phase, or both. The choice to sample only the particle phase or only the vapor phase seems obvious for many contaminants due to their extremely high or low vapor pressures. This work identifies some chemicals that are likely to occur in both the vapor and particle phases in some atmospheres and identifies others for which readily available information may be inadequate or misleading. The saturated vapor concentration (SVC) of numerous chemical substances was calculated from vapor pressure information given in the Documentation of the Threshold Limit Values and Biological Exposure Indices published by the American Conference of Governmental Industrial Hygienists (ACGIH). The results were used to calculate the ratio of SVC to the threshold limit value (TLV) for each substance. Forty-one substances that had a TLV listed only in mg/m3 were found to have a SVC gr...