1,2-Dichloroethane in Indoor Air

1,2-Dichloroethane is a manmade compound used in the production of vinyl chloride. Due to its toxicity, it generally has relatively low screening levels based on acceptable concentrations in indoor air, soil vapor, and groundwater. If a release of 1,2-dichloroethane has occurred, the compound may be detected in the subsurface and could be a risk driver for vapor intrusion (VI). Based on studies presented in this paper, however, this compound has become more frequently detected in indoor air and is likely attributed to sources in the buildings being sampled. This paper summarizes current knowledge of indoor air background levels of 1,2-dichloroethane and potential sources. Recent field data demonstrate that the typical indoor air concentrations for this compound are higher than those reported in the past and may be connected to a larger presence of internationally shipped materials in the current indoor environment than in previous decades. This is an important consideration when evaluating buildings for VI, as background indoor air concentrations of 1,2-dichloroethane may confound the VI pathway assessment.