Document ID: EPA-HQ-OAR-2017-0670-0025
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2018-09-12T04:00Z

MEMORANDUM

DATE:	May 25, 2018

SUBJECT:	Technology Review for the Surface Coating of Large Appliances Source Category

FROM:	Eastern Research Group, Inc.

TO:		Kim Teal, OAQPS/SPPD/MMG

1.0	INTRODUCTION	

Section 112 of the Clean Air Act (CAA) requires the U.S. Environmental Protection Agency (EPA) to establish technology-based standards for listed source categories. These technology-based standards are often referred to as national emissions standards for hazardous air pollutants (NESHAP) and are based on the maximum achievable control technology (MACT). The National Emission Standards for Hazardous Air Pollutants: Surface Coating of Large Appliances (40 CFR part 63 subpart NNNN), hereinafter referred to as the Large Appliances NESHAP, regulates emissions of hazardous air pollutants (HAP) from facilities that are major sources and are engaged, either in part or in whole, in the surface coating of large appliances. The Large Appliances NESHAP requires the use of MACT to reduce HAP emissions from the following operations: surface preparation; mixing; coating; curing; conveying coatings, thinners and cleaning materials; and waste storage and handling. 

Section 112 also contains provisions requiring the EPA to periodically revisit these standards. Specifically, section 112(d)(6) states:

      (6) REVIEW AND REVISION.  -  The Administrator shall review, and revise as necessary (taking into account developments in practices, processes, and control technologies), emissions standards promulgated under this section no less often than every 8 years.

To comply with this CAA requirement, the EPA conducted a technology review for the Large Appliances NESHAP for major sources. This memorandum addresses the technology review for all large appliance surface coating processes. For this exercise, we considered any of the following to be a "development":

 Any add-on control technology or other equipment that was not identified and considered during development of the original MACT standard;
 Any improvements in add-on control technology or other equipment (that were identified and considered during development of the original MACT standard) that could result in additional emissions reduction;
 Any work practice or operational procedure that was not identified or considered during development of the original MACT standard;
 Any process change or pollution prevention alternative that could be broadly applied to the industry and that was not identified or considered during development of the original MACT standard; and
 Any significant changes in the cost (including cost effectiveness) of applying controls (including controls the EPA considered during the development of the original MACT standard).
 
In addition to reviewing the practices, processes, and control technologies that were considered during the development of the 2002 NESHAP, we reviewed a variety of data sources in our investigation of potential practices, processes, or controls to consider. Among the sources we reviewed were the NESHAP for various industries that were promulgated after the Large Appliances NESHAP. We reviewed the regulatory requirements and/or technical analyses associated with these regulatory actions to identify any practices, processes, and control technologies considered in these efforts that could be applied to emission sources in the Large Appliance Surface Coating source category, as well as the costs, non-air impacts, and energy implications associated with the use of these technologies. Finally, we reviewed information from other sources, such as state and/or local permitting agency databases and industry-supported databases.

Section 2 of this memorandum presents a summary of the sources of data that were used to conduct the technology review and Section 3 presents the technology review for large appliance surface coating operations. 

2.0	SOURCES OF AVAILABLE CONTROL TECHNOLOGY INFORMATION

To identify any developments in practices, processes, or control technologies that could be applicable to surface coating operations in the large appliance industry, we researched the following sources of information: the EPA's RACT/BACT/LAER Clearinghouse, publicly-available state Air Permit databases, regulatory actions promulgated subsequent to the Large Appliances NESHAP, regional and state regulations, site visits, and industry information.  

2.1	RACT/BACT/LAER Clearinghouse Database

Under the EPA's New Source Review (NSR) program, if a company is planning to build a new plant or modify an existing plant such that criteria air pollution emissions will increase by a certain amount (in tons per year, depending on the pollutant), then the company must obtain an NSR permit. The NSR permit is a construction permit which generally requires the company to minimize air pollution emissions by changing the process to prevent air pollution and/or installing air pollution control equipment. 

The terms "RACT," "BACT," and "LAER" are acronyms for different program requirements relevant to the NSR program.  RACT, or Reasonably Available Control Technology, is required on existing sources in areas that are not meeting national ambient air quality standards (non-attainment areas). BACT, or Best Available Control Technology, is required on new or modified major sources in clean areas (attainment areas). LAER, or Lowest Achievable Emission Rate, is required on new or modified major sources in non-attainment areas. 

BACT and LAER (and sometimes RACT) are determined on a case-by-case basis, usually by State or local permitting agencies. The EPA established the RACT/BACT/LAER Clearinghouse, or RBLC, to provide a central database of air pollution technology information (including past BACT and LAER decisions contained in NSR permits) to promote the sharing of information among permitting agencies and to aid in future case-by-case determinations. However, data in the RBLC are not limited to sources subject to RACT, BACT, and LAER requirements. Noteworthy pollution prevention and control technology decisions and information may be included even if they are not related to past RACT, BACT, or LAER decisions. 

The RBLC contains over 5,000 air pollution control permit determinations that can help identify appropriate technologies to mitigate most air pollutant emission streams. It was designed to help permit applicants and reviewers make pollution prevention and control technology decisions for stationary air pollution sources, and includes data submitted by several U.S. territories and all 50 States on over 200 different air pollutants and 1,000 industrial processes.
	
The RBLC provides several options for searching the permit database on-line to locate applicable control technologies. We conducted a search of the RBLC processes specific to the large appliances surface coating category permits dating back to 1990.  The search results included the following data fields:
 
::	RBLC ID;
::	Facility Name, and State;
::	Permit Date;
::	Process name;
::	Throughput;
::	Pollutant;
::	Control technology; and
::	Percent efficiency of control.

A search by process type for large appliance surface coating facilities provided no results. However, searching the RBLC by company name for large appliance manufacturers (obtained from the National Emission Inventory) resulted in one result for Whirlpool Marion Division. The RBLC record for this facility did not provide any additional information that could be used in this technology review, but did include the subpart NNNN HAP content limit (0.13 kg/L coating solids) and a VOC content limit. The results of the search for the large appliances source category are presented in Appendix 1. 

2.2	Subsequent Regulatory Actions

Regulatory actions promulgated subsequent to the July 23, 2002 Large Appliances NESHAP have been identified for sources similar to large appliance surface coating sources. The regulatory actions listed in Table 1 were reviewed for developments in practices, processes and control technologies.

   Table 1. Subsequent Regulatory Actions for Sources Categories Similar to 
                      Large Appliance Coating Operations

                                MACT Standards
                                    Subpart
                               Date Promulgated
           Practices, Processes, and Control Technologies Evaluated
           Surface Coating of Miscellaneous Metal Parts and Products
                                     MMMM
                                  01/02/2004
Emission limit as mass HAP per volume solids used, add-on control devices, low-HAP coatings (Ultraviolet (UV) curable, electron beam-curable), powder coatings
                 Surface Coating of Plastic Parts and Products
                                     PPPP
                                  04/19/2004
Emission limit as mass HAP per mass solids used, add-on control devices, low-HAP coatings (Ultraviolet (UV) curable, electron beam-curable)
             Surface Coating of Automobiles and Light-Duty Trucks
                                     IIII
                                  04/26/2004
Emission limit as mass HAP per volume solids used. Develop and implement a work practice plan to minimize organic HAP.
                            Residual Risk Standards
                                    Subpart
                               Date Promulgated
   Practices, Processes, and Control Technologies Identified as Developments
                         Shipbuilding and Ship Repair
                                      II
                                  11/21/2011
Concentrator/RTO installed on spray booths to achieve 95% control efficiency; lower volatile organic compounds (VOC) coating limits based on California regional rules
                         Wood Furniture Manufacturing
                                      JJ
                                  11/21/2011
RTO; Lower VOC coating limits based on California regional rules, more efficient spray guns.
Bans conventional spray guns except when the overspray is routed to a control device.
                      Aerospace Manufacturing and Rework
                                      GG
                                   12/7/2015
                                No developments

Developments identified in the regulatory actions listed in Table 1 will be discussed in Section 3 (Technology Review for Surface Coating Operations).

2.3	State Rules and State Operating Permits

As part of this technology review, we researched state VOC rules that were developed in response to control technique guidelines (CTGs) developed by EPA and state permits. The CTGs established VOC limits to control VOC emissions. The technologies recommended by the CTGs to control VOC also provide control of HAP emissions. Therefore, as part of this review we reviewed the state operating permits to compare the VOC and HAP limits to the CTG and NESHAP limits. 

State Rules

In 1977 and again in 2007, the EPA published CTGs to control VOC emissions from surface coating of large appliances. According to the 2007 CTG, 21 states had adopted the 1977 limit of 2.8 lb VOC/gal of coating applied (minus water) into their rules for large appliance surface coating sources.

The 2007 CTG recommendations were based on Bay Area and South Coast air district rules in California. The Bay Area Air Quality Management District (BAAQMD) Regulation 8, Rule 14, covers surface coating of large appliances (and metal furniture) and establishes VOC limits of 2.3 lbs/gal (less water and exempt compounds) for baked coatings and 2.8 lbs/gal for air dried coatings. The BAAQMD rule does not establish separate limits for any specialty coating categories. 

The South Coast Air Quality Management District (SCAQMD) Rule 1107 for Surface Coating of Metal Parts and Products also covers large appliances. SCAQMD Rule 1107 establishes a VOC limit of 2.3 lbs/gal (less water and exempt compounds) for baked and air-dried general one-component coatings and baked general multi-component coatings, and a VOC limit of 2.8 lbs/gal for air-dried multi-component coatings. The 2007 CTG for large appliance coatings also adopted the SCAQMD Rule 1107 VOC limits for categories of specialty coatings.
 
The 2007 CTG recommends emission limits for general purpose one component and multicomponent coatings, and for several types of specialty coatings (extreme high gloss, extreme performance, heat resistant, metallic, pretreatment coatings, and solar absorbent coatings). For each coating type, the 2007 CTG also recommends separate limits for baked and air dried coatings. The 2007 CTG recommends that as an alternative to the VOC content limits, allowing facilities to use add-on controls. The 2007 CTG also recommends work practices to reduce emissions from cleaning materials, and the use of high-efficiency coating application methods.

For this technology review, the EPA compiled information for 10 major source large appliance facilities subject to subpart NNNN which are located in seven states. Six of the facilities are located in four states that adopted the 1977 CTG limits, and four facilities are located in two states (Ohio and Wisconsin) that adopted the 2007 CTG limits. However, the 2007 CTG limits were not adopted statewide and none of the four facilities are actually subject to the 2007 CTG limits since the facilities are not located in counties to which the 2007 VOC limits apply. However, one facility (Whirlpool Findlay Division in Findlay, OH) is using a thermal oxidizer on one line to comply with the 1977 CTG VOC limit.   

State Operating Permits

The National Emissions Inventory (NEI) presents comprehensive and detailed estimates of air emissions based on data provided by State, Local, and Tribal (SLT) air agencies. NEI point sources include large industrial facilities, such as Large Appliance coating facilities, that submit their own inventories to SLT air agencies. We compiled State operating permits for all 10 of the facilities subject to subpart NNNN that reported large appliance surface coating emissions to the NEI. In reviewing the emissions limits we noted: 

 No permit has an organic HAP limit lower than the Large Appliance NESHAP HAP limit;
 No permit includes a limit on individual HAP; and 
 No facilities are subject to VOC limits more stringent than the 2007 CTG VOC limit. 

In addition, we noted that only two facility permits indicated add-on controls for the subpart NNNN coating operations: 

 One facility (Whirlpool Findlay Division in Findlay, OH) uses a TO for VOC control but was using the subpart NNNN compliant material option for HAP control; and 
 One facility (Erler Industries in North Vernon, IN) uses RTOs for the coating operations in three of the five "plants" at the facility; although the permit did not specify the subpart NNNN compliance option, an inspection report from 2017 indicated that the facility is using the emission rate with add-on control compliance option.
 No other facilities have add-on controls for VOC or organic HAP and all others are using the compliant materials option or the emission rate without add-on controls option.   
            
The relevant details from the permits are summarized in Appendix 2 . 

2.4	Site Visits 

The EPA is planning to conduct site visits to large appliance surface coating facilities for this technology review. 

2.5 	Industry Information

When subpart NNNN was first promulgated, the EPA estimated 74 existing facilities, and the NESHAP would reduce HAP emissions by 1,080 Mg/yr, a 45-percent reduction from baseline levels. The EPA estimates there are currently 10 major source large appliance surface coating facilities. The reduction in the number of major source facilities could be due to a variety of factors, but one factor may be that many facilities have switched to powder coating and other low-HAP coating technologies and were able to reduce HAP emissions to below the major source threshold before the subpart NNNN compliance date. As a result, these facilities were not major sources and were not subject to the NESHAP.

We reviewed the American Coatings Association's (ACA) Industry Market Analysis (9th edition) to identify new technologies. The chapter on appliance coatings stated that the industry has shifted significantly away from liquid coatings to powder coatings and pre-coated metal coil substrate. The market analysis stated that the volume of liquid finishes used in appliance finishes decreased by 67 percent between 2007 and 2014 as a result of the shift to powder coatings and pre-coated metal coils.

According to the ACA Market Analysis, appliance manufacturers have lately preferred to minimize in-house coating operations and thereby also minimize associated burden with respect to regulatory compliance and potential issues with quality and productivity losses. As an alternative, many manufacturers have tried to maximize the use of pre-coated coil substrate in place of in-house painting, and this has resulted in significant reduction of HAP and VOC emissions from these facilities. The ACA Market Analysis also noted that the adoption of both powder coating and the use of pre-coated metal coil has benefited consumers because appliance manufacturers are making higher quality products at a more attractive price through increased efficiency. 

The ACA Market Analysis stated that liquid coating appliance finishes have evolved over the last three decades from low-solids and to higher-solids acrylic coatings, but even higher solids acrylics were still a VOC liability, and most manufacturers using liquid coatings have shifted to high-solids polyesters which can be formulated with lower VOC. 

3.0	TECHNOLOGY REVIEW FOR SURFACE COATING OPERATIONS

As defined in the Large Appliances NESHAP, a coating is a material that is applied to a substrate for decorative, protective or functional purposes. Such materials include, but are not limited to, paints, porcelain enamels, sealants, caulks, inks, adhesives, and maskants, but does not include decorative, protective, or functional materials that consist only of protective oils, acids, bases, or any combination of these substances. Emissions from coating operations occur when solvent evaporates as it is being applied. The amount of HAP and VOC emitted during coating operations is a function of the HAP content of the coatings and the amount of coating used in the operation. 

The amount of coating used in the operation is affected by the application method's transfer efficiency. The more efficient a coating application method is in transferring coatings to the large appliance component or product, the lower the volume of coatings (and therefore solvents) needed per given amount of production and the lower the HAP and VOC emissions. The Large Appliance NESHAP does not require operators to account for application method transfer efficiency in the compliance calculations or to use high-efficiency coating application methods.

The primary HAP emitted from large appliance surface coating operations are organic HAP and, based on the 2011 NEI, include xylene, glycol ethers, toluene, methanol, ethyl benzene, methylene chloride and methyl isobutyl ether (MIBK), in order of decreasing importance. Eighty percent of the HAP emissions from the large appliances category occur from the coating operations and the remaining HAP come from the cleaning operations. In most cases, HAP emissions from mixing and storage areas are relatively small. At the time of the rule promulgation, most large appliance surface coatings were applied either by using a spray gun in a spray booth or by dipping the substrate in a tank of coating.

3.1	Summary of Existing MACT Level of Control

The Large Appliances NESHAP promulgated in 2002 requires separate organic HAP emission limits for new/reconstructed and existing sources:

 An existing affected source must limit organic HAP emissions to the atmosphere to no more than 0.13 kilogram per liter (kg/liter) (1.1 pound per gallon (lb/gal)) of coating solids used during each compliance period.

 A new or reconstructed affected source must limit organic HAP emissions to the atmosphere to no more than 0.022 kg/liter (0.18 lb/gal) of coating solids used during each compliance period.

Compliance is determined monthly based on the average emissions over that monthly compliance period. An affected source can comply with the above average monthly organic emission limits by using one of the following three compliance options:

 Compliant material option -- the organic HAP content of each coating used in the coating operation(s) is less than or equal to the applicable emission limit, and each thinner and each cleaning material used must contain no organic HAP. 

 Emission rate without add-on controls option -- weighted average based on data for the coatings, thinners, and cleaning materials used in the coating operation(s), the organic HAP emission rate for the coating operation(s) must be less than or equal to the applicable emission limit.

 Emission rate with add-on controls option -- weighted average based on data for the coatings, thinners, and cleaning materials used in the coating operation(s) and the emission reductions achieved by emission capture and add-on controls, the organic HAP emission rate for the coating operation(s) must be less than or equal to the applicable emission limit.

Facilities using emission capture systems and add-on controls are required to meet operating limits for the capture system and add-on control. In addition, the rule sets work practice standards for any coating operation or group of coating operations for which the facility uses the emission rate with add-on controls option to demonstrate compliance.

We reviewed state operating permits for those facilities for which a permit was available to determine the types of controls and compliance options used by these facilities. These permits are summarized in Appendix 2. Not all permits specified the compliance option in subpart NNNN the facility was using. Only two of the permits indicated that the facilities had add-on controls for the metal furniture coating operations. One facility had a thermal oxidizer for VOC control, but was using the compliant material option in subpart NNNN for HAP control. The second facility had RTOs for the coating operations in three of the five "plants" at the facility; the permit did not specify the compliance option used by the facility, but a recent (2017) inspection report indicated that the facility was using the emission rate with add-on controls compliance option. No facilities were subject to HAP content limits more stringent than those in the NESHAP and no control technologies were identified that were not considered during the development of MACT in the original NESHAP.

From the preamble to the proposed rule, (65 FR 81134, December 22, 2000), the technical basis for the MACT determination for the large appliance source category was the use of lower-HAP coatings, thinners, and cleaning materials to control organic HAP emission. Add-on capture and control systems for organic HAP were rarely used by the industry, according to the proposal preamble. The preamble also reported that, while lower organic HAP materials are broadly used throughout the industry, each particular coating technology is not used at every facility and facilities use various combinations of low-HAP coatings, thinners, and cleaning materials. Thus, the MACT determination was based on an evaluation of each facility's organic HAP emissions from all coating-related operations.

3.2	Identified Control Measures for Surface Coating Operations

3.2.1	Add-On Control Technology or Other Equipment Not Identified and Considered During MACT Development

Add-on control technologies considered during MACT development of the Large Appliances NESHAP for the reduction of organic HAP included an emission capture system (such as a spray booth) used in conjunction with thermal recuperative oxidizers, regenerative thermal oxidizer (RTO), catalytic oxidizers, and activated carbon adsorbers. Carbon adsorption units or oxidizers can also be used to control organic HAP emissions from cleaning operations.

Subsequent RTR NESHAPs have identified the following as developments:

      Shipbuilding and Ship Repair: The EPA identified an add-on control device, a concentrator/RTO, recently installed (2009) at one shipbuilding and ship repair facility in California. The control device consisted of rotary concentrators followed by RTOs on five large, custom-built spray booths to control volatile organic emissions from some of the coating operations. The system is capable of achieving 95 percent control efficiency for the VOHAP emissions captured by the spray booths (which are estimated to capture 90 percent of the VOHAP emissions). However, the EPA found that the use of this technology would only be practical and affordable at certain facilities building new ships for surface coating pre-assembled modules and would not be affordable for facilities performing ship repair and surface coating of completed ships. The EPA estimated the cost-effectiveness of the concentrator/RTO system to be $305,000 per ton of VOHAP reduced when used in ship building and repair. 
      
      Wood Furniture Manufacturing: The technology review identified the use of a RTO on a spray booth as a development for the coating of flat panels using an automated high-speed coating process. The technology review identified one facility using this control and fewer than five facilities that could install this technology. The technology review determined that this technology was not affordable for the facilities that were not currently using it.

The use of an RTO (with a permanent total enclosure, PTE) was considered during development of the Large Appliances NESHAP as a control technology capable of achieving an efficiency of 95 percent and greater and was included in the basis of the proposed and final standards for new and existing sources, but was rejected as not cost effective. The other examples provide no new information that would imply that there have been changes or advancement in RTO technology that would change that decision. Therefore, EPA does not consider the use of an RTO/PTE to be an advancement in technology for the large appliance source category. 

3.2.2	Improvements in Add-On Control Technology or Other Equipment for Organic HAP Emissions That Was Identified and Considered During MACT Development

The BACT determinations in the RBLC database that were made subsequent to promulgation of the Large Appliances NESHAP specify the use of add-on controls, including capture systems with a RTO and induction heater and catalytic oxidation. All of these control technologies were in use during development of the Large Appliances NESHAP and were considered in the development of MACT. 

3.2.3	Work Practices and Procedures Not Identified and Considered During MACT Development

No additional work practices or procedures were identified that were not already identified and considered during MACT development. 

The current MACT standards require that, if a facility uses add-on controls to comply with the emissions limitations, the facility must develop and implement a work practice plan to minimize organic HAP emissions from the storage, mixing, and conveying of coatings, thinners, and cleaning materials used in, and waste materials generated by, those coating operations. These work practices include the following:
 All organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be stored in closed containers.
 Spills of organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be minimized.
 Organic-HAP-containing coatings, thinners, cleaning materials, and waste materials must be conveyed from one location to another in closed containers or pipes.
 Mixing vessels which contain organic-HAP-containing coatings and other materials must be closed except when adding to, removing, or mixing the contents.
 Emissions of organic HAP must be minimized during cleaning of storage, mixing, and conveying equipment.

If a facility is not using add-on controls and is using either the compliant material option or the emission rate option, the facility does not need to comply with work practice standards. Under the compliant material option, the materials covered by the work practices would be either non-HAP, or would already be compliant with numerical HAP content limits. Under the emission rate without add-on controls option, HAP emitted from spills or from containers would be counted against the facility in the compliance calculations, so facilities must already minimize these losses to maintain compliance.
 
3.2.4	Any process change or pollution prevention alternative that could be broadly applied that was not identified and considered during MACT development

Pollution prevention measures, specifically coating product reformulations and alternatives to liquid coatings, are currently used by the large appliance industry and were considered during the MACT floor development. These include high-solids low-HAP, waterborne, and powder coatings. In the MACT floor development, emissions from cleaning were included in the overall emission rate calculations for each facility and reflected the use of low-HAP solvent blends for cleaning. In the final rule, emissions from cleaning are also included in each facility's compliance calculations. As described in the review of the ACA Market Analysis, the large appliance industry has largely adopted the use of powder coating and high-solids low-HAP and waterborne coatings in the past decade.

One alternative that was not considered in the development of the Large Appliance NESHAP was the use of high efficiency coating application methods. This includes high-volume low-pressure (HVLP) spray guns, air-assisted airless spray, and electrostatic spray. The technology review conducted for the Wood Furniture Manufacturing NESHAP identified the use of more efficient spray guns as a development, and adopted regulations preventing the use of conventional spray guns. The Wood Furniture Manufacturing NESHAP identified the use of air assisted airless spraying as a more efficient coating application technology.  

High volume low pressure (HVLP) and electrostatic spraying systems are the primary high efficiency spray methods used by the aerospace and automobile refinishing industries and are examples of the high efficiency spray application methods required by the Aerospace Manufacturing Rework Facilities NESHAP and the Automobile and Light Duty Truck Surface Coating NESHAP (40 CFR 63 Subparts GG and IIII, respectively). HVLP spray guns use high volumes (10 to 25 standard cubic feet per minute (scfm)) of low pressure (2 to 10 pounds per square inch gauge (psig)) air to deliver the paint. The lower air pressure creates a lower particle speed, resulting in a more controlled spray pattern with less overspray and bounce back from the substrate. With electrostatic spray systems, atomized particles of coating acquire an electric charge as they pass through a high voltage field at the end of the spray nozzle.  This electric charge causes the particles to be attracted to the parts being painted, which are electrically grounded.

Based on the examples above, we believe that high transfer efficiency spray equipment could represent a change/improvement in technology that was not considered in the original NESHAP. High transfer efficiency spray equipment includes the use of flow coat, roll coat, brush coat, dip coat, electrostatic attraction, or high-volume low-pressure (HVLP) spray guns. 

The Large Appliances NESHAP does not currently include provisions for using high-efficiency coating application methods. This alternative was not considered during the development of NESHAP. The use of high-efficiency coating application methods is a pollution prevention alternative that would reduce the amount of coating consumed during application compared to conventional coating spray application technologies. High efficiency coating application methods result in greater transfer efficiency than conventional spray, meaning more coating would be applied to the part and less would become waste in the form of coating overspray. In turn, this would also reduce organic HAP emissions. Because the EPA did not consider the use of high-efficiency coating application methods in the development of the Large Appliances NESHAP, this could be considered to be a pollution prevention alternative that could be broadly applied that was not identified and considered during MACT development. 

In addition to high efficiency coating application methods employing electrostatic attraction, airless spray, air-assisted airless spray, or HVLP spray guns, there are high efficiency non-spray methods (e.g., flow coat, roll coat, brush coat, dip coat) that can achieve emission levels equivalent to HVLP or electrostatic spray guns. 

The efficiency of alternative coating application methods can be demonstrated by comparing the emissions generated by the alternative application method to the emissions generated by HVLP or electrostatic application methods according to the California South Coast Air Quality Management District's "Spray Equipment Transfer Efficiency Test Procedure for Equipment User, May 24, 1989" and "Guidelines for Demonstrating Equivalency with District Approved Transfer Efficient Spray Guns, September 26, 2002."

The majority of large appliance surface coating facilities subject to subpart NNNN are already required to use HVLP or an equivalent application technology by state rules in Indiana, Ohio, and Wisconsin to limit VOC emissions. It is likely that large appliance surface coating facilities in the two other states (Iowa and Minnesota) are also using high-efficiency application equipment for spray applied coatings as a cost saving measure to reduce coating and spray booth filter consumption and to reduce the amount of solid waste generated in the form is used spray booth filters.

If a large appliance surface coating facility was required to replace any of their conventional coating spray guns with a higher efficiency spray guns, such as an HVLP spray gun, a 2007 EPA analysis estimated that the cost to do so would be a capital cost of approximately $700 per gun. The 2007 analysis estimated these costs for an industrial quality HVLP spray gun and accessories (e.g., larger diameter hose, gauges, extra air caps), based on vendor information. Assuming a 10-year life and a 7 percent interest rate, the annualized capital cost per HVLP gun would be $100. However, these potential costs would be offset by savings in coating costs, filter costs, and in the cost of solid waste disposal for used paint booth filters that would result from increased coating transfer efficiency and the reduced generation of coating overspray, compared to conventional spray guns.

Other pollution prevention measures that are currently used by the industry are being driven by product substitution, reformulation and the use of pre-coated substrate. Paint manufacturers are continuing to develop waterborne, higher solids, and powder coating formulations that replace conventional solvent-borne coatings. These coatings are generally available and often are not produced and marketed specifically for the large appliance coating industry. Powder coatings, waterborne, higher solids coatings with lower HAP and VOC content and powder coatings were considered in the development of the proposed and final standards, and are reflected in the HAP emission limitations in the final rule. The development and use of pre-coated coil was discussed above in Section 2.3 in the context of the information provided in the American Coatings Association's market analysis. We did not identify any developments in coating technology in the information reviewed that would represent a development relative to the coating technologies on which the final rule is based.

In conclusion, high-efficiency spray equipment meets the technology review criteria of a pollution prevention alternative that could be broadly applied to the Large Appliance coating source category. This technology was not identified and considered during MACT development.

3.2.5 	Significant changes in the cost (including cost effectiveness) of applying controls (including controls the EPA considered during the development of the original MACT standards)

In developing the 2002 large appliances NESHAP, the EPA did not specifically examine the cost-effectiveness of adopting a standard based on add-on controls. The EPA examined the cost effectiveness of standards for large appliance coating more stringent than the MACT floor using an analysis for metal furniture coating based on switching completely to powder coating and non-HAP cleaning solvents. In a 2000 memorandum, also for metal furniture coating, the cost effectiveness of an enclosure (e.g., spray booth) and thermal oxidizer on a typical metal furniture coating source was estimated at approximately $44,000 to remove each ton of organic HAP. These analyses are relevant to large appliance coating because the coating processes in the two source categories are similar and use similar strategies to reduce emissions. The control costs estimated during the Metal Furniture NESHAP development have not been revisited or updated, but it is expected that the prevalence of low VOC and low HAP coatings, and the availability of powder coating, have made enclosures and add-on controls less cost effective since the NESHAP was developed. Therefore, the cost to remove each ton of organic HAP over and above the emission reductions under the current level of control would be substantially higher than the cost of $44,000 per ton estimated when the NESHAP was developed. As noted earlier, only one of the major source facilities that are subject to subpart NNNN is using add-on controls to comply with the NESHAP emission limits. 
Appendix 1. Practices, Processes and Control Technologies Identified for Large Appliance Operations in the January 17, 2017 Query of the RBLC Database
                                    RBLC ID
                                 (Permit Date)
                                       
                                 Facility Name
                                       
                                     State
                                       
                                 Process Name
                                       
                                   POLLUTANT
                                       
                              Emission Limitation
                            Emission Reduction (%)
OH-0337
(10/2010)
Whirlpool Corporation Marion Division
OH
Small Parts E-Coat line with cure oven
VOC

HAP
0.90 kg/L of applied coating solids,
0.13 kg/L of coating solids (subpart NNNN)
NA

Appendix 2. State Permit Search Results
                                       
                                 Facility Name
                                       
                                     State
                                       
                              Process Description
                                       
                                   Pollutant
                                       
                                Control Method
                            Emission Reduction (%)
Polar King International, Inc
IN
Walk-in Freezer Surface Coating Line
HAP
Compliant material or emission rate without add-on control options
NA
Whirlpool Corporation - Clyde Operations
OH
Electrocoating dip tank
HAP
Compliant material or emission rate without add-on control options
NA
Whirlpool Findlay Division
OH
Electrocoat Prime Coat and Ransburg Finish Paint System;
Nylon Dishrack Powder Coating Line.
HAP
Compliant material or emission rate without add-on control options for HAP.
NA

East and West Metal Dishrack Adhesion Promoter and Powder Coating Operations  -  Two Lines.
VOC, HAP
Thermal oxidizer for VOC from adhesion promoter; Compliant material or emission rate without add-on control options for HAP.
Thermal oxidizer: OAC of 87% (90% DRE) for VOC.

Whirlpool Corporation - Marion Operations
 
OH
Ecoat #1: dip one coat, rinse, oven;
Ecoat #2: dip one coat, rinse, oven;
Powder paint #1;
Small parts E-Coat and rinse stages and cure oven.
HAP
Compliant material option or emission rate with no add-on control
NA
Western Industries
WI
Top coating (2 lines);
Electro-deposition coating and curing ovens (2 lines)
HAP
Compliant materials option
NA
Whirlpool Corporation  -  Amana Division
IA
Powder Coating Line Cure Oven
HAP
Compliant material or emission rate without add-on control options for HAP.
NA
Erler Industries, Inc. 
IN
Multiple surface coating lines (manual and robotic) in five plants
VOC, HAP
Three of the five plants have RTOs; an inspection report from June 2017 indicates the facility is using the emission rate with add-on controls compliance option.
Not known.
Innovent Air Handling Equipment, LLC
MN
Coating Lines
VOC, HAP
Compliant material option or emission rate with no add-on control
NA