- 11 September 2006 -
EPA Proposes Residual Risk Air Emission Standards for Halogenated Solvents

The Environmental Protection Agency (EPA), under its authority to control residual risk, has proposed to place a cap on emissions from machines that use halogenated solvents for cleaning parts.  71 Fed. Reg. 47670 (August 17, 2006).  Halogenated solvent cleaning is generally used in conjunction with industrial processes such as plating, painting, inspections, repair, assembly, heat treatment, and machining.

In 1994, the EPA promulgated technology-based emission standards for hazardous air pollutants from the halogenated solvent cleaning source category, referred to as the Halogenated Solvent Cleaners MACT Standard.  These requirements prompted facilities to make significant changes in how and what halogenated solvents were used for cleaning parts. Under section 112(f) of the Clean Air Act, the EPA is required to evaluate the remaining risk to public health and the environment following the implementation of technology-based standards such as the Halogenated Solvent MACT Standard. The EPA's recent proposal is intended to provide further reductions of halogenated solvent emissions beyond the controls imposed by the 1994 technology-based MACT standard.

According to the EPA, if lifetime cancer risk from exposure to halogenated solvents exceeds one in a million, then more stringent residual risk standards are needed.  Based on its risk findings, the EPA has proposed two regulatory options to cap the facility-wide emissions of methylene chloride (MC), perchloroethylene (PCE) and trichloroethylene (TCE) from both new and existing halogenated solvent cleaning machines. Option One would impose a facility cap to reduce emissions of halogenated solvents by approximately 60 percent; Option Two would impose a cap to reduce emissions by approximately 70 percent. 

Regardless of the regulatory option, these new residual risk standards could impose significant burdens on facilities that use halogenated solvents for cleaning parts. The EPA has requested comments on these two regulatory options and the potential impacts on the halogenated solvents cleaning source category. 

Interested parties must submit comments to EPA on the proposal by October 2, 2006.