What mil plastic is considered impermeable?
The regulation does not specify a particular thickness of plastic sheeting considered to be impermeable, but rather includes a performance standard. The performance standard requires firms to isolate the work area, prevent dust and debris from exiting, and ensure plastic sheeting is not torn or displaced. Certain guidance materials recommend the use of 6 mil plastic sheeting, such as HUD's Guidelines for the Evaluation and Control of Lead-Based Paint in Hazards in Housing. However, for the purpose of Renovation, Repair, and Painting regulation, a contractor should choose one or more layers of plastic sheeting of a sufficient thickness to prevent puncture based on the circumstances of the particular project.