EPA programs of vinyl chloride monitoring in ambient air.

Before development of an emission standard for vinyl chloride, the Environmental Protection Agency (EPA) conducted three programs to measure vinyl chloride (VC) concentrations in air around plants which either manufacture VC or use it. A brief monitoring survey conducted by EPA Regional Offices found VC in ambient air around poly(vinyl chloride) (PVC) production plants. As a consequence of this survey, a second monitoring program was established to measure VC in the air around VC and PVC production plants. This program found some relatively high concentrations of VC in ambient air around the plants. This program found maximum 24-hr average rations concentrations ranging from 0.32 to 10.6 parts of VC per million parts of air. The program also found an apparent relationship between certain emission excursions and ambient VC concentrations. A third monitoring program was established to measure VC around PVC fabrication plants. This monitoring program found much less VC around PVC fabrication plants than around VC and PVC production plants. In conclusion, VC was found in ambient air around VC production plants and PVC fabrication plants. However, the data show that much less VC escapes into surrounding air from PVC fabricating plants than from VC and PVC production plants.