National Emission Standards for Hazardous Air Pollutants: Asphalt Processing and Asphalt Roofing Manufacturing

This action promulgates national emission standards for hazardous air pollutants (NESHAP) for existing and new asphalt processing and asphalt roofing manufacturing facilities. The EPA has identified asphalt processing and asphalt roofing manufacturing facilities as major sources of hazardous air pollutants (HAP) such as formaldehyde, hexane, hydrogen chloride (HCl), phenol, polycyclic organic matter (POM), and toluene. The final standards will implement section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet HAP emission standards reflecting the application of the maximum achievable control technology (MACT). The total HAP reduction resulting from compliance with the rule is expected to be 86 megagrams per year (Mg/yr). A variety of HAP are emitted from asphalt processing and asphalt roofing manufacturing source categories. The following HAP account for the majority (approximately 98 percent, based on the emission factors developed for the final rule) of the total HAP emissions: Formaldehyde, hexane, HCl (at asphalt processing facilities that use chlorinated catalysts), phenol, and toluene. The remaining two percent of the total HAP emissions is a combination of several different organic HAP, each contributing less than 0.5 percent to the total HAP emissions.