MON MACT Impact
The clock is ticking for paint and coating operations to reduce HAP emissions and meet EPA guidelines.
November 10, 2003 will likely be viewed as a watershed date by paint and coatings operations across the country. On that date, the United States Environmental Protection Agency (EPA) published the final MON MACT rule that strictly limits air emissions from batch and continuous chemical manufacturers including paint and coatings companies. Existing facilities impacted by the new rule have until November 10, 2006 to be in full compliance with the provisions.
What is MON MACT?
According to the EPA’s Proposed Standards for Hazardous Air Pollutant Emissions from Miscellaneous Organic Chemical Manufacturing and Miscellaneous Coating Manufacturing published in September 2001, Section 112 of the Clean Air Act (CAA) authorizes the EPA to establish national standards to reduce air emissions from sources that emit one or more hazardous air pollutants (HAPs). Section 112(b) lists the HAPs to be regulated under such standards, while section 112(c) directs the EPA to use this information to develop and publish a list of source categories for which national emission standards for hazardous air pollutants (NESHAP) will be developed.
The EPA must list all known source categories and subcategories of “major sources” that emit one or more of the listed HAPs. Section 112(a) defines a major source category as “any stationary source or group of stationary sources located within a contiguous area under common control that emits, or has the potential to emit, in aggregate, considering controls, 10 tons per year or more of any one HAP or 25 tons per year or more of any combination of HAP.”
The list of source categories includes several organic chemical processes collectively organized in the Miscellaneous Processes Group. The processes in this miscellaneous group form the basis of the source categories addressed by the standards known as the Miscellaneous Organic NESHAP (MON). In order to control, reduce or otherwise limit hazardous air pollutant emissions from miscellaneous organic chemical processes, add-on controls are often required to achieve such reductions as part of the process known as maximum achievable control technology (MACT).
More than 120 different organic and inorganic HAPs are emitted from major sources covered by the MON, but only eight HAPs account for approximately 75% of total HAP emissions. These are methanol, hydrochloric acid, cresols, methylene chloride, methyl ethyl ketone, toluene, xylene and vinyl acetate.
What Impact Will MON MACT Have?
MON MACT is likely to affect both existing and future facilities across the country and will apply to all batch and continuous chemical manufacturers not already subject to a MACT rule. It will cover the production of a variety of substances including paints, coatings, inks, adhesives and resins, and it is designed to regulate major source HAP emissions from process vents, storage tanks, wastewater streams, transfer operations and equipment leaks (fugitive emissions).
Emissions from these operations will be strictly limited and will require coating and resin manufacturers to install covers and add-on control equipment to reduce HAPs. For example, under the new guidelines, 98% of HAP emissions from transfer operations and process vents must be controlled; 95% of emissions from storage tanks must be controlled. Because the new ruling determines a facility’s source category based on both current emissions as well as the potential to emit, it’s possible the rule could apply to facilities even though they fall below current emissions thresholds.
Emission Control Technology Options
Complying with the new emission regulations could involve major capital outlays or changes in basic process operations for some facilities. To determine if a facility falls under the category of a major source for HAPs, the plant manager should perform a thorough emissions inventory.
Once the emissions that fall under the MON rule have been identified along with current control requirements, managers can review various control options. In some cases, a facility that exceeds a HAP limit by only a small amount might be able to replace those HAPs with non-HAP VOCs. In other situations, the installation of a control device might be required to destroy the HAP emissions before they are released to the outside atmosphere.