This proposal will address the agency's technology review of the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Chemical Manufacturing Area Sources (CMAS). This NESHAP was promulgated pursuant to section 112(d) of the Clean Air Act (CAA) and established emission limitations and work practice requirements for controlling emissions of hazardous air pollutants (HAP). The CMAS NESHAP, subpart VVVVVV, was promulgated on October 29, 2009. The NESHAP controls HAP emissions from process vents, storage tanks, equipment leaks, wastewater streams, transfer operations and heat exchange systems. This action implements the technology review requirements of CAA section 112(d)(6) which requires the EPA to review and revise the standards as necessary, taking into account developments in practices, processes and control technologies, no less often than every 8 years.