Under authority of CAA Section 112(d) (4), we promulgated standard procedures to allow owners and operators to establish a health-based emission limit for total chlorine in lieu of compliance with the section 112(d) (2) MACT emission standard. The health-based approach is available to all hazardous waste combustors except hydrochloric acid production furnaces. Because we finalized the MACT standard for total chlorine as a surrogate to control metal HAP for the hydrogen chloride production furnace source category, we did not allow any alternative to the chlorine standard for this source category.
The alternative health-based emission limit for total chlorine would be based on national exposure standards established by EPA that ensure protection of public health with an ample margin of safety. The standard would consist of assuring that individual source emissions will not exceed a nationally-applicable, uniformly protective national exposure standard. Each source's standard would be based on site-specific input from each source choosing to use this approach.
This approach was consistent with section 112(d)(4) standard which EPA has promulgated for certain nonhazardous waste-burning combustion sources.
For more information, visit the hazardous waste combustion web page.