SIC #3821 - Thermoplastics Manufacturing 

Rule Type:  Title III MACT Standard 

Status:  Proposed Rule 

Scope 

EPA has proposed a MACT standard for the thermoplastics manufacturing industry. This industry produces poly(ethylene terephthalate) (PET), polystyrene, acrylonitrile butadiene styrene (ABS), methyl methacrylate acrylonitrile butadiene styrene (MABS), methacrylate butadiene styrene (MBS), styrene acrylonitrile (SAN), acrylonitrile styrene acrylate/alpha methyl styrene acrylonitrile (ASA/AMSAN), and nitrile resins. 

The proposed rule limits emissions from process vents, storage vessels, wastewater operations, equipment leaks, heat exchange systems, and process contact cooling towers. For continuous process vents, the proposed rule requires emissions reductions of 98 percent. For batch process vents, 90 percent control or the use of a compliant flare is required. 

EPA intends to require enhanced monitoring to demonstrate continuous compliance with the MACT rule. This enhanced monitoring generally takes the form of control device parameter monitoring, e.g., continuous measurement of temperature upstream and downstream of the catalyst bed in a catalytic incinerator. 

The MACT rule covers 66 existing facilities in 23 states. All of these facilities are major sources of hazardous air pollutants (HAP), i.e., each emits at least 10 tons/year of a single HAP, or 25 tons/year of a combination of HAP. Significant HAP covered by the rule include styrene, acrylonitrile, butadiene, ethylene glycol, methanol, acetaldehyde, and dioxane, depending upon the resin being produced. EPA expects the rule to result in an overall reduction in emissions of about 47 percent or 13,000 tons/year at existing sources. These facilities are shown in Figure V-9, pages 1 and 2. 

Total capital costs are estimated at $98 million and annual operator costs are $12 million with a cost effectiveness of $1,160/ton of HAP removal.