Presumptive Maximum Achievable

Control Technology

for the

Paper and Other Web Coating

Source Category

Coatings and Consumer Products Group

Emission Standards Division

Office of Air Quality Planning and Standards

May 1997

PAPER AND OTHER WEB COATING

PRESUMPTIVE MACT

I.	Overview of Presumptive MACT and Next Steps for MACT	I-1

II.	Summary of Presumptive MACT Development Process	II-1

III.	Summary of Comments	III-1

Coating Limit	III-1

Applicability	III-1

Alternative Controls	III-2

Compliance Demonstration	III-2

Averaging	III-2

Definitions	III-2

Other Comments	III-2

IV.	Paper and Other Web Coating

Recommendation for Presumptive MACT	IV-1

Background	IV-1

Definitions	IV-2

Coating	IV-2

Coating Applicator	IV-2

Coating Line	IV-2

Major Source	IV-2

Coating Applicator	IV-2

Potential to Emit	IV-2

Printing Operations	IV-3

Applicability	IV-3

Presumptive MACT	IV-3

Emission Limitations	IV-4

Compliance Options	IV-5

Current Industry Control Status	IV-5

Resources	IV-6

Attachment 1	Minutes from the January 30, 1997

Paper and Other Web Coating Stakeholders

Presumptive MACT Meeting	A.1-1

Attachment 2	Summary of Solvent-Based to Waterbased

Adhesive-coated Substrate Retrofit	A.2-1

Attachment 3	Summary of Pollution Prevention Measures

for Cleaning Operations	A.3-1

I. Overview of

Presumptive MACT and Next Steps for MACT

Presumptive Maximum Achievable Control Technology (PMACT) was established by the EPA with stakeholder input from Federal, State and local environmental agencies and industry representatives. PMACT was based on readily available information which has limitations. PMACT is intended to provide preliminary information for conducting case-by-case MACT determinations. It is also intended to identify areas which require further investigation during the development of a final MACT standard.

Analysis of the readily available data and stakeholder input has led to the following PMACT emission limitations for paper and other web coating:

1)	At least 95-99 percent overall control efficiency (capture and control) using an add-on control device for emissions from a coating line, as calculated over a calendar month; or

2)	no more than 0.20 kg HAP applied per kg coating solids applied, as calculated on a weighted average basis for each calendar month for all coatings used; or

3)	no more than 0.20 kg HAP emitted per kg coating solids applied, as calculated on a weighted average for all coatings used each calendar month.

These emission limitations are applicable to coating lines. One of the limitations of the existing data is that we could not agree as to how representative the data is of the entire paper and other web coating industry. Therefore, rather than using the limited data to establish a MACT floor of 99 percent overall control efficiency, we provided the overall control efficiency range of 95-99 percent. By providing this range, we acknowledge that current technology has resulted in overall emission reductions as high as 99 percent; however, the extent of this level of control efficiency within the industry is currently unknown.

Another limitation to the readily available data is that only a very small portion of the various coatings used in the industry were represented. This presented a major hurdle in providing a pollution prevention alternative for the paper and other web coating PMACT. In the end, there was general agreement that in the absence of data for the paper and other web coating industry, we should utilize the results of MACT efforts for similar industry operations. In this effort we turned to the recently promulgated MACT for Printing and Publishing (40 CFR Part 63 Subpart KK). The materials applied by the product and packaging rotogravure and wide web flexographic printing industry are, in many cases, the same or similar to the materials applied in coating operations. Therefore, we utilized the HAP content limit of 0.20 kg HAP per kg solids applied; and the HAP emission rate of 0.20 kg HAP emitted per kg solids applied from that standard.

In addition to the similarity in materials applied, the application methods and emission control strategies use by the product and packaging rotogravure and wide web flexographic printing industry, are also the same or similar to those employed by the paper and other web coating industry. Therefore, we also reached general agreement that the applicable compliance provisions included in the Printing and Publishing MACT Standard should be utilized as guidance in developing compliance demonstrations with the paper and other web coating PMACT.

The development of the final MACT standard for paper and other web coating will continue to gather additional information specific to this industry. This information will be utilized to identify any distinctions between printing and coating operations that may exist. The information will also be used to calculate a more precise MACT floor, rather than the current overall control efficiency range; and will enable us to develop pollution prevention alternatives that are directly correlated with the paper and other web coating industry. This may result in a MACT standard with emission limitations that are different than those being presented as PMACT.

II. Summary of

Presumptive MACT Development Process

In developing considerations for Presumptive Maximum Achievable Control Technology (P-MACT), the EPA project team developed a database of 43 coating lines using EPA's Source Test Information Retrieval System (STIRS) database (which includes test reports from nationwide facilities) and several Title V permit applications. These data are shown in Attachment 1. Next, the EPA considered coating emission limits included in current regulations for sources similar to Paper and Other Web Coating, specifically, the Pressure Sensitive Tape Manufacture New Source Performance Standard (NSPS), the Printing and Publishing National Emission Standard for Hazardous Air Pollutants (NESHAP), the Magnetic Tape Coating NESHAP, and the Flexible Vinyl Coating NSPS (see Attachment 1). The "Regulatory Subgroup," consisting of the EPA project team and, EPA Regional and State/Local Agency representatives, convened to discuss the Presumptive MACT process, the potential approaches to Presumptive MACT, and to identify additional information needed to aid the Presumptive MACT process.

Using this information, members of the Regulatory Subgroup developed a draft recommendation for Presumptive MACT. This draft recommendation weighed the differences between the current regulations for other industries and the Paper and Other Web Coating industry, as well as considered current coating line controls and known performance capabilities of the add-on control devices used in the Paper and Other Web Coating industry. The Regulatory Subgroup concurred with the draft recommendation for Presumptive MACT on November 14, 1996.

On January 30, 1997, a third Presumptive MACT meeting/conference call was held with the Regulatory Subgroup along with a number of industry representatives (called "Stakeholders"). In this meeting, the Regulatory Subgroup's recommendation for Presumptive MACT was presented and industry concerns and recommendations were discussed (see meeting notes in Attachment 1). Subsequently, a revised draft Presumptive MACT was prepared and presented at a fourth Presumptive MACT meeting with the Regulatory Subgroup on April 18, 1997. A fifth and final Presumptive MACT meeting was held on April 30, 1997, with the Regulatory Subgroup, and Stakeholders, where a Final Draft Presumptive MACT was presented.

III. Summary of Comments

The EPA received verbal comments from industry on Presumptive MACT during the January 30, 1997, Stakeholders meeting as well as written comments from the following companies: Rexam Custom, Matthews, NC; Pressure Sensitive Tape Council, Chicago, IL; Chemical Fabrics and Film Association, Inc., Cleveland, OH (see meeting minutes in Attachment 1). As a result of some of these comments, changes were made to Presumptive MACT for Paper and Web Coating that are reflected in the attached Final Presumptive MACT. However, some comments were not within the scope of Presumptive MACT and will be carried onto the next step of the process and considered during MACT development.

The following is a summary of comments received that are addressed in this final Presumptive MACT:

Coating Limit

A proposed equivalent coating limit was criticized because the pre-control coating in the example calculation was not considered representative of the industry, and also because it did not provide for the use of reactive coatings, that do not emit all of the HAP contained in the coating. The Presumptive MACT for Paper and Other Web Coating was revised to include emission limitations based on either 0.2 kg HAP emitted per kg coating solids applied or 0.2 kg HAP applied per kg solids applied. The 0.2 kg/kg level is similar to the previously calculated example of an equivalent coating limit. However, industry stakeholders suggested that this limit is more representative of the various coatings used in the industry.

Applicability

Comments were received in regard to which part of the coating process does the Presumptive MACT apply. Presumptive MACT was changed to clarify that the emission limitations apply to the coating line, defined to include coating processes from web unwind to rewind or cutting station. Although data was not available to establish specific emission limitations for other sources of emissions (e.g. cleaning, mixing, storage, solid waste and waste water handling, etc.), these sources should be considered in case-by-case MACT determinations.

Alternative Controls

Comments were received requesting that alternative controls be allowed under Presumptive MACT for Paper and Other Web Coating. Presumptive MACT was revised to clarify that the emission limitation, in the form of an overall control efficiency range, is intended to allow for traditional as well as innovative emission controls. The HAP content limit and HAP emission rate are intended to allow for pollution prevention alternatives, or a combination of pollution prevention and control equipment.

Compliance Demonstration

Numerous comments were received requesting compliance demonstration techniques for Presumptive MACT. Presumptive MACT was revised to reference the applicable compliance demonstrations described in the Printing and Publishing NESHAP. Other regulations for similar sources may also be referred to for applicable compliance demonstrations.

Averaging

A number of comments were received requesting that averaging of emissions be allowed. Presumptive MACT was revised to include monthly weighted averages, which draws from the Printing and Publishing NESHAP as well as other regulations for similar sources.

Definitions

Comments were received requesting definitions of some of the terms used in Presumptive MACT. A separate "Definitions" section was added to Presumptive MACT to describe terms that may be needed in its implementation.

Other Comments

Other comments were received from Stakeholders and other interested parties concerning the intent of the applicability of the Presumptive MACT for Paper and Other Web Coating. These comments raise the issue of the "grey" area between the definition of printing vs. coating, that may inadvertently cause operations to be included in the Paper and Other Web Coating source category. This presumptive MACT is not intended to include printing operations; however, the distinction between printing and coating is not well defined. The EPA will continue to investigate this issue during the MACT process.

IV. Paper and Other Web Coating

Recommendation for Presumptive MACT

Background

Section 112 of the Clean Air Act (CAA) mandates that the Environmental Protection Agency (EPA) promulgate national emission standards for hazardous air pollutants (NESHAP) on a strict schedule. The CAA mandates that the NESHAP's for each source category require sources to implement maximum achievable control technologies (MACT) to reduce emissions of hazardous air pollutants (HAP).

The MACT standard for the Paper and Other Web Coating source category is scheduled for promulgation in 2000. If the EPA fails to meet this deadline by more than 18 months, Section 112(j) of the CAA includes a "hammer" provision requiring that operating permits for major sources contain HAP emission limitations determined to be equivalent to MACT. The equivalency determinations are to be made on a case-by-case basis for individual sources.

The EPA is currently on schedule with the Paper and Other Web Coating MACT standard and, therefore, it is unlikely that case-by-case MACT determination will be required under Section 112(j). However, between the current date and the promulgation date of 2000, there is a possibility that case-by-case MACT determinations will be required for newly constructed and/or reconstructed major sources under Section 112(g).

Section 112(g) requires case-by-case MACT determinations for sources where no applicable emission limitations have been established. The final 112(g) rule governing case-by-case MACT determinations for constructed or reconstructed sources was published in the Federal Register on December 27, 1996 (61 FR 68384). This rule requires case-by-case MACT for new and reconstructed major sources to be consistent with "new source MACT," i.e., no less stringent than the emission control that is achieved in practice by the best controlled similar source.

Constructed and reconstructed major sources are defined in the final regulations governing constructed or reconstructed major sources promulgated on December 27, 1996(61 FR 68384); and are summarized as follows:

Construct a Major Source-- 1)to fabricate, erect or install at any greenfield site a stationary source which emits or has the potential to emit 10 tons per year of any one HAP or 25 tons per year of any combination of HAP, or, 2)to fabricate, erect or install at any developed site a new process or production unit which in and of itself emits or has the potential to emit 10 tons per year of any one HAP or 25 tons per year of any combination of HAP (hereafter referred to as a "unit"). However, if a newly constructed unit at an existing site meets specific criteria of the rule, it is exempt from the requirement of case-by-case MACT.

Reconstructed Major Source--the replacement of components at an existing unit whenever: 1) the fixed capital costs of the new components exceed 50 percent of the fixed capital cost to construct a comparable unit, and 2) it is technically and economically feasible for the reconstructed major source to meet MACT.

Definitions

The following are definitions of some of the important elements in this recommendation for Presumptive MACT:

Coating--A material applied onto or impregnated into a substrate for protective, decorative, or functional purposes. Such materials include, but are not limited to, paints, varnishes, sealants, adhesives, inks, maskants, and protective coatings; and are often, but not always, applied across the entire width and/or length of the substrate.

Coating Applicator--An apparatus used to apply a surface coating.

Coating Line--Any number or combination of coating applicators, flash-off areas, and ovens that coat a continuous web, located between a web unwind and rewind or cutting station.

Coating Operation--Those activities in which a coating is applied to a substrate and is subsequently air dried, cured in an oven, or cured by radiation.

Major Source--A source that emits, or has the potential to emit, 10 tons per year or more of any one HAP or 25 tons per year or more of total HAP.

Potential to Emit--The maximum capacity of a stationary source to emit a pollutant under its physical and operational design. Any physical or operational limitation on the capacity of the stationary source to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design if the limitation or the effect it would have on emissions is federally enforceable. For purposes of Section 112(g), the December 27, 1996 rulemaking (61 FR 68384) states that the EPA will accept limitations that are practicably enforceable by a State and local air pollution control agency.

Printing Operations--The formation of words, designs, and pictures on a substrate through the application of material to that substrate.

Applicability

This source category includes facilities that apply coatings to a web substrate to produce a wide range of products, that include but are not limited to the following: pressure sensitive tapes and labels, photographic film, flexible packaging, decorative and industrial laminates, sandpaper and other abrasives, gaskets and other sealing devices, and wall and floor coverings. Facilities only coating fabric, however, will be covered under a separate NESHAP for fabric coating.

This Presumptive MACT applies to those activities in which a coating is applied to a substrate and is subsequently air dried, cured in an oven, or cured by radiation. The specific coating equipment to which this Presumptive MACT applies is considered to include any number or combination of coating applicators, flash- off areas, and ovens that coat a continuous web, located between a web unwind and rewind or cutting station. Other associated operations (e.g. cleaning, mixing, storage, waste handling, etc.) should also be considered in case-by-case MACT determinations; however, specific emission limitations for these operations are not available at this time.

Presumptive MACT

To assist in making case-by-case MACT determinations under Sections 112(g) and (j), the Regulatory Subgroup for Paper and Other Web Coating, with input from industry Stakeholders, established the Presumptive MACT emission limitations listed below. These limits include an overall control efficiency range as well as HAP content and emission limits.

It is intended that presenting overall control efficiency levels as a range will allow for the use of traditional as well as innovative control technologies. Various technology options are thereby allowed, including, but not limited to, thermal and catalytic oxidizers, carbon adsorbers, solvent recovery systems, bioreactors, etc. It is also assumed that 100 percent capture efficiency is achievable and reasonable, since a number of facilities currently are known to achieve 100 percent capture using permanent total enclosures (PTE).

Case-by-case determinations of "new source MACT" under Section 112(g) are expected to rely on the high end of the total control efficiency range. Case-by-case determinations for existing sources under Section 112(j) would not occur unless the EPA misses the 2000 promulgation date for the MACT standard by more than 18 months. Therefore, it is likely that additional data will be compiled and available for use before any determinations under Section 112(j) would potentially be necessary.

The HAP content limits are intended to provide for pollution prevention alternatives. A formulation limit has been provided so that Presumptive MACT can be achieved without source testing. The HAP emission limit is intended to account for coating materials that become part of the product and, therefore, are not emitted, e.g., reactive coatings. However, a source test may be needed in this case to demonstrate that HAP emissions are below the limit.

Emission Limitations

Based on the currently available data and comments from the stakeholders involved, Presumptive MACT for HAP emissions from Paper and Other Web Coating is any one or combination of the following:

1)	At least 95-99 percent overall control efficiency (capture and control) using an add-on control device for emissions from a coating line, as calculated over a calendar month; or

2)	no more than 0.20 kg HAP applied per kg coating solids applied, as calculated on a weighted average basis for each calendar month for all coatings used; or

3)	no more than 0.20 kg HAP emitted per kg coating solids applied, as calculated on a weighted average for all coatings used each calendar month.

The regulatory subgroup also encourages case-by-case MACT determination to include emission limitations on other sources of HAP including, but not limited to, cleaning, mixing, storage, wastewater, and solid waste operations at Paper and Other Web Coating facilities. The currently available data are not sufficient to support a Presumptive MACT determination on these other emission sources at this time; however, data will continue to be gathered on other emission sources and current industry control measures through surveys of the industry in the MACT development process. It is likely that MACT for these other emission sources will be based on control measures currently in use by the industry, e.g., modification of work practices, use of compliant low-HAP solvents, equipment standards, etc. Therefore, States making case-by-case MACT determinations for facilities in this industry are encouraged to look at what other facilities located in their State and other states are doing to reduce emissions. See also other regulations for similar solvent-use sources listed below.

Compliance Options

Compliance options for emission limitations 1) and 2), can be established using the Printing and Publishing NESHAP as a guide. The relevant compliance provision in the Printing and Publishing NESHAP can also be used in developing compliance options for emission limitation 3). When considering reactive coatings, the compliance provision in the Printing and Publishing NESHAP can account for multicomponent reactive coatings through the use of test Method 24 (which allows a one to 24 hour reaction period prior to heating the sample in ASTM Method D-2369).

For reactive coatings that do not react under the specified conditions of this ASTM method, a more creative technique may need to be developed for case-by-case MACT compliance. This may require a source test under operating conditions which could set the bound for compliance (i.e., compliance could be demonstrated by showing that performance measures for operations during the compliance period remain within the bounds of the performance measures of the operating conditions of the source test). States may need to work with the facility being studied for case-by-case MACT to establish the exact relationship between the facility's operating conditions and the test conditions. The EPA will be investigating this issue further during the MACT development process; a more exact description of this type of compliance technique could be part of the final MACT for Paper and Other Web Coating.

Current Industry Control Status

The data collected from test reports and permit applications; discussions with trade associations representing the industry; and site visits that EPA has made to Paper and Other Web Coating facilities show that carbon adsorbers and thermal oxidizers are the primary control devices being used by the industry. Some facilities also use catalytic oxidizers.

In addition to control devices, many facilities in the industry have installed PTE. While the extent of PTE is not precisely known, about 20 percent of the facilities in the EPA's limited database utilize PTE. The regulatory subgroup believes that PTE can readily be installed on new coating lines that are subject to case-by-case MACT under Section 112(g).

Some facilities in the industry have chosen to use low VOC/HAP coatings rather than install control devices to reduce emissions, and some are using a combination of low-emitting coatings and control devices. Some information on low-emitting coatings is included in a study by the Office of Research and Development(ORD)a.

Resources

Additional information may be obtained from the EPA's MACT database as it continues to grow. The MACT database (also called the AIRS/AFS database) can be accessed through the EPA's Technology Transfer Network Chief Bulletin Board or the EPA's website on the Internet (http://ttnwww.rtpnc.epa.gov).

In addition, NESHAP and NSPS developed for other surface coating operations may help to identify compliance options and/or control measures applicable to the Paper and Other Web Coating industry. These regulations are as follows:

Printing and Publishing Industry, 40 CFR Part 63 Subpart KK; Printing and Publishing Industry--
Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (EPA-453/R-95-002a).

Pressure Sensitive Tape and Label Surface Coating Industry, 40 CFR 60 Subpart RR; Pressure Sensitive Tape and Label Surface Coating Industry--Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (EPA-450/3-80-003a).

Flexible Vinyl Coating and Urethane Coating and Printing Operations, 40 CFR 60 Subpart FFF; Flexible Vinyl Coating and Printing Operations--Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (EPA-450/3-81-016a).

Magnetic Tape Manufacturing Industry, 40 CFR 60 Subpart SSS, and 63 Subpart EE; Magnetic Tape Manufacturing Industry--Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (EPA-450/3-85- 029a); and

Hazardous Air Pollutant Emissions from Magnetic Tape Manufacturing Industry--Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina (EPA- 453/R-94-074b).

Polymeric Coating of Supporting Substrates, 40 CFR 60 Subpart VVV; Polymeric Coating of Supporting Substrates--Background Information for Proposed Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina

(EPA-450/3-85-022a).

The ORD report on pollution prevention measures for cleaning operationsb may also be useful for other potential sources of HAP emissions.

Attachment 1

Minutes from the January 30, 1997

Paper and Other Web Coating Stakeholders

Presumptive MACT Meeting

Date:	February 3, 1997 (revised March 21, 1997)

Subject:	Meeting Minutes for Paper and Other Web Coating Integrated Rule Development: January 30, 1997 Presumptive MACT Stakeholder Meeting

From:	Dan Brown

To:	Roundtable Meeting Participants

A roundtable meeting for the integrated development of rules for the paper and other web coating industries was held on January 30, 1997, in Research Triangle Park, North Carolina. Following are the minutes from that meeting. Section I includes an overview of the presentations, and Section II includes questions that were asked during the meeting and the U. S. Environmental Protection Agency (EPA) responses (Section II also includes a summary of written comments received as of March 6, 1997). The meeting attendees and teleconference participants are listed in Attachment A, and Attachment B includes a copy of the handouts from the meeting. Most of the information presented by EPA and Midwest Research Institute (MRI) is included in the handouts. Therefore, Section I only presents highlights of the presentations.

I.	Overview of Presentations

Mr. Dan Brown, the EPA project lead, began the meeting by presenting the meeting agenda and then proceeded with introductions of the meeting participants. Dan requested that all teleconference participants fax their name, company or agency, and telephone number to his office so that a complete list of all participants could be included with the meeting minutes.

Dan presented several overheads that provided an overview of PMACT and the PMACT development process, and then briefly discussed the requirements of Section 112(g) of the Clean Air Act (CAA). During the discussion of the 112(g) requirements for a newly constructed major source, Ms. Janet Bowen added that the requirements are based on potential to emit. Following the discussion of Section 112(g), Dan introduced Ms. Susan Rasor, Midwest Research Institute project lead.

Susan presented several overheads that detailed the information sources that were considered for developing PMACT, including existing new source performance standards (NSPS)for portions of the source category; MACT standards developed for similar sources (e.g., Printing and Magnetic Tape); and, readily available data from test reports, literature searches, and permits. Susan discussed the advantages and disadvantages of each source of information, and presented a table showing emission data (including capture and control efficiencies from about 41 coating lines) that were used for developing PMACT. Susan then turned the discussion over to Dan.

Dan then presented several overheads that included a summary of issues and concerns related to PMACT raised by the regulatory subgroup. The discussion focused on the limited existing data, and in particular, the lack of data for a pollution prevention alternative. An example for calculating a potentially equivalent coating limit was presented on one overhead, but Dan emphasized that the calculation was only an example and was based on very limited data. Several comments and questions were posed regarding this example calculation. Dan stated that EPA would welcome data and suggestions for an equivalent coating limit. Following the discussion of concerns about PMACT, Dan presented the regulatory subgroup responses to the concerns and then presented the draft PMACT recommendation and the rationale for the recommendation. Dan then turned the discussion back over to Susan.

Susan discussed the additional data needs for the MACT development. She focused on the use of surveys, and the steps that will follow the receipt of survey responses. Following several questions, Susan turned the meeting back over to Dan, who presented a project status report and then opened the meeting to questions.

Dan stated that the meeting minutes would be distributed to the meeting participants.

II.	Questions and Responses

Question	Can EPA clarify the use of PMACT in case-by-case MACT determinations?

Response	For case-by-case MACT determinations, PMACT is intended as preliminary guidance to states and affected sources. PMACT represents what the eventual MACT standard is likely to be based on readily available data today.

Question	Did the test report data (used in developing PMACT) represent all segments of the paper and other web coating industry?

Response	No. The data only represent what was readily available.

Question	Did the facilities that reported 100 percent capture efficiency have permanent total enclosures?

Response	Yes.

Question	Suppose data gathered from surveys show that PMACT is too stringent. Can MACT be less stringent than PMACT?

Response	Yes. Since PMACT is based on very limited data and additional data will be used to determine MACT, it is possible that MACT will not be the same as PMACT and may be less stringent.

Comment	When facilities are faced with meeting a regulation, they often will over-control sources in anticipation of a more stringent future regulation.

Question	What industry does the available test data represent?

Response	See the attached table of existing data.

Comment	Release coatings often have much higher HAP contents (20 to 30 kg HAP/kg solids) than the maximum content presented in the example calculation for an equivalent coating limit.

Comment	The example calculation for an equivalent coating limit shows a coating limit range from 0.18 to 0.04 kg HAP/kg solids. The 0.04 value is a very small number that even water-based coatings may not meet.

Response	Agree. The example was intended to illustrate one methodology that could be used to derive an equivalent coating limit. The values in the calculation are not being considered as options.

Question	Why not present a percent HAP option like the printing rule?

Response	This will likely be part of the MACT standard, but we do not have enough data to propose a reasonable number at this time.

Question	Why not use the printing and publishing coating limit?

Response	It may not accurately represent the paper and other web coating industry. At this time, EPA does not have enough data to propose a coating limit, and the example calculation shows a method for calculating a limit but does not suggest using the calculated limit.

Comment	Please don't disregard NSPS limits.

Comment	The PSTC would feel comfortable with a HAP limit of 0.2 lb/lb solids.

Comment	If States are allowed to set their own coating limits, some facilities may have an advantage.

Response	All case-by-case MACT determinations must be uploaded to the AIRS/AFS data base so that other States can access the information.

Comment	Some HAP are part of a coating but are not emitted, such as in the production of high-pressure decorative laminate.

Response	This will be taken into account when selecting limits for MACT.

Question	Why are carbon adsorbers not mentioned under pollution prevention alternatives?

Response	Carbon adsorbers are considered add-on controls. EPA's definition of pollution prevention focuses on source reduction. Carbon adsorbers do not meet this definition.

Question	Janet Bowen mentioned a data base that contains information on case-by-case MACT determinations. What is this data base called and where is it located?

Response	The data base is called the AFS MACT data base and is part of the AIRS/AFS data base. This data base can be accessed through the TTN (CHIEF Bulletin Board) or the EPA web-site on the Internet.

Question	If case-by-case MACT determinations made by States are inconsistent, how can EPA assure that MACT will not be more stringent than all of the case-by-case determinations.

Response	Nothing precludes MACT from being more stringent than case-by-case MACT determinations.

Question	The lowest coating limit of 0.04 kg HAP/kg solids is a very tiny number. What good is it?

Response	Again, this number is part of an example, and has no significance other than that.

Question	Will there be a coating HAP level below which facilities will not have to count the HAP content?

Response	It is likely that such a level will be determined as we gather more data for MACT development, however, with the limited available data, such a provision is not included in PMACT.

Comment	The overall suggested control range goes from 95 to 99 percent. The upper end of this range cannot be achieved without steady state conditions, which are not typical of coating operations. Are any control device companies willing to guarantee 99 percent destruction?

Comment	The lower end of the range is difficult to achieve with carbon adsorbers.

Comment	The data sets are probably based on three one-hour tests, which are not the same as real-time situations.

Response	Up to this point we have not fully considered these issues. It is likely that we will look at the MACT standards developed for similar source categories to establish compliance demonstration procedures.

Comment	Catalytic oxidizers have significant fluctuations.

Response	For other standards, EPA has set special monitoring requirements for the use of catalytic oxidizers on coating operations.

Comment	When you go over 95 percent control, you start forcing the use of thermal oxidizers, and this causes the release of CO and NOx to the atmosphere. EPA needs to examine pollution prevention alternatives.

Question	Does anyone have data that show how pollutant concentration affects control efficiencies?

Response	(Response provided by Dale Kalina) Yes. Thermal oxidizer outlet concentrations remain relatively constant when inlet concentrations drop.

Comment	Control equipment companies don't want a rule that sets control levels that they cannot guarantee

Comment	With regard to capture efficiency determination, Method 204 is difficult to run and does not seem to be any more accurate than a liquid/gas mass balance.

Comment	Please list existing NESHAP and NSPS as tools for States to use for pollution prevention alternatives.

Question	Can the standard mention that sources with emissions below a certain level are exempt?

Response	Yes.

Question	Can averaging be written in to PMACT and MACT?

Response	Averaging is likely to be included in MACT; EPA will look at discussing averaging in the PMACT recommendation.

Comment	Maybe EPA can just state that averaging is an option.

Comment	Please include guidance on averaging.

Question	Will EPA be using Section 114 authority to gather data?

Response	Yes. EPA will likely send two versions of a survey to each identified facility. One of the surveys will be the generic survey that has been approved by OMB for use in obtaining data for MACT development under Section 114. A second version of the generic survey will likely be developed more specifically tailored to the coating industry. This "coating specific" survey would be more user-friendly to the paper and other web coating industry requiring less time to fill out. The facility would choose which one of the surveys to respond to.

Question	How will EPA get surveys to everyone that needs to fill one out?

Response	EPA is trying to identify facilities through the trade associations, and is also consulting business directories to identify smaller companies that may be affected by the rule.

Question	How long does industry have to complete the survey?

Response	Typically, six weeks.

Question	Can EPA provide a copy of the survey on disk?

Response	EPA needs to provide hard copies to all facilities because of the various types and versions of software currently in use. If an individual facility would like the computer file, they can contact Dan Brown.

Question	Can industry provide comments on the survey before being required to fill it out?

Response	EPA began this process by soliciting comments on the surveys from various industry groups. It became evident that if EPA allows everyone to comment, the information collection will be set back several months if not longer. However, EPA may accept limited comments provided in a timely fashion.

Comment	Please take into account other regulatory deadlines that many facilities are facing when setting deadlines for survey submittal.

Response	EPA understands that unavoidable conflicts may arise. If such a conflict arises, facilities should contact Dan and request additional time to complete surveys.

Question	Who does a BAC rule apply to?

Response	Under Section 183(e) of the Clean Air Act, BAC applies to coating manufacturers. However, for this industry it is likely that a CTG will be determined to be as effective as a rule and, therefore, a CTG could be issued in lieu of a BAC rule. Under this scenario, the CTG would include reasonably available control techniques applying to the end-user of the coatings.

Question	Is it possible that the existing paper coating CTG could be revised.

Response	Yes. The existing CTG will be the starting point.

Question	What is the baseline year for survey data?

Response	The establishment of a base year for data collection may be inappropriate. The MACT floor is to be calculated based on control technology used in practice. This infers that data collection efforts should obtain the most recent available data. We sent some surveys out in 1996 and requested 1995 data since we believed this was the most recent complete year of data.

Comment	This choice of 1995 as a baseline year may penalize facilities that participated in an early reduction program such as the 33/50 program. The early reduction program began in 1987, which was also the first year of the toxic release inventory (TRI).

Response	EPA used 1995 as the base year for the initial survey and may continue collecting 1995 data for consistency or may request 1996 data since that is now likely to be the most recent complete year of data.

Question	What is the deadline for submitting written comments on PMACT?

Response	One month.

Question	Will a section be added on data gaps?

Response	Yes, particularly for compliance options.

Question	Will the regulation be based on the current HAP list? Specifically, if a HAP is added to the list, will it be included in determining compliance with the regulation?

Response	The MACT standard will be developed for reducing those HAP on the current list. In the event that a HAP is added to the list after the MACT standard is promulgated, it would not be regulated by the standard unless the standard was revised to include it.

Comment	No single pollution prevention option will satisfy all segments of the industry.

Response	Agree. That is why EPA provides multiple compliance options.

Summary of Written Comments Received as of March 6, 1997

Rexam Custom, February 18, 1997

•	An overall control efficiency of 95% to 96% is reasonable but higher than that is probably not supported.

•	Technologies other than thermal destruction should be considered.

•	The future likely includes 100% permanent total enclosures, an engineering effort that seems reasonable.

•	A pollution prevention alternative should be included and somewhere around 0.2 kg HAP/kg solids applied is strongly recommended

Flexible Packaging Association, February 25, 1997

•	The Agency should promote the printing and publishing MACT as the primary reference for states making case-by-case MACT determinations since printing and coating operations are often controlled by the same devices and common sense suggests consistent requirements across these operations.

•	FPA is concerned that it is the Agency's intent to include different control requirements for case-by-case MACT determinations under 112(j) and 112(g) and, therefore, encourages the EPA to remain on schedule to avoid case-by- case MACT determinations under 112(j).

•	The recommended 95% to 99% overall control efficiency does not include compliance guidance and the variations of business cycles typical to the industry do not allow for consistently certifying this level of control.

•	FPA does not agree that 3.5 kg organic solvent per kg solids represents coatings with the highest solvent contents and recommends that a real-life example with compliance options (such as the printing and publishing MACT)be included.

•	Other sources of HAP emissions (e.g. mixing, storage, cleaning, etc.) Should not be included in a MACT determination.

Chemical Fabrics and Film Association, February 28, 1997

•	In determining the ratio of kg HAP per kg solid the EPA should adjust its assumptions regarding the highest solvent levels, or, allow averaging to more appropriately account for the range of formulations used within the industry.

•	Although it is possible that some technologies could achieve a 99% overall control efficiency, this efficiency rate does not have general applicability and additional documentation is needed to establish that such a level is realistically achievable and measurable.

•	"Coating" must be clearly defined, particularly in regard to identifying operations subject to PMACT and MACT.

•	Shifting to water-borne technology will not be a viable means of compliance in all cases and shifting coating technology may result in additional issues (e.g. efforts to reformulate coatings to replace HAP with other VOC may be a waste of resources if control of VOC emissions is required).

•	Good data is critical to an achievable and realistic standard and EPA should distribute surveys broadly to the industry and allow sufficient time for meaningful responses.

Pressure Sensitive Tape Council, March 5, 1997

•	EPA should consider using the NSPS subpart RR as a floor for case-by-case MACT, using the MACT standards for printing and publishing, and magnetic tape is not appropriate for our industry since the coatings are different and scientific data does not clearly link control capability and control equipment types.

•	Consideration should be given to the capabilities and complexities of various control options and overall control efficiencies should be reflected by control device (e.g. oxidizers are less complex but use non-renewable petroleum- based resources and contribute greenhouse gases whereas recovery systems, although more complex with ancillary equipment increasing potential for losses and reducing efficiency, reduce the solvent demand and are pollution prevention alternatives).

•	EPA's data on solvent content versus solids content is not valid since our industry uses many coatings with 99% solvent.

•	The current NSPS for pressure sensitive tapes and labels contains reasonable performance and compliance expectations for the current technology. Considering the production and loading variables typical to the industry, higher control efficiencies and short term emission limits become very difficult to show compliance with.

•	Emission calculations should account for residual solvent that remains in the product and is not emitted.

•	Test Method 24 for VOCs is unreliable and unrepresentative for water-borne coatings and alternative methods should be provided.

•	A clear concise definition of what emissions should be included in the capture efficiency calculations is needed (e.g. emissions from mixing related operations and/or coating applicators).

•	The Agency should use the current NSPS limit of 0.2 kg VOC/ kg solids applied for PMACT and include plant-wide averaging (as provided in the printing and publishing MACT). The Agency should use caution setting limits below this level as it may result in requiring controls for water-based coatings which would be energy intensive and costly.

•	Regulated facilities should be provided with several options for meeting limits.

•	The affected "Source" must be clearly defined, we believe the source is the entire coating line from un-wind to re- wind including capture and control devices.

•	Plant-wide PMACT should be considered rather than each source.

•	PMACT should not include control of emissions from cleaning, tanks, storage, etc., these operations at coating facilities are comparable to the same operations at printing facilities and, therefore, work practice standards identified in the printing and publishing MACT would be appropriate.

•	PMACT and MACT should be written to minimize interpretation and variability in establishing permit conditions and limitations.

Attachment A - Meeting Participants

Attendees:

Name	Affiliation

Dan Brown	U.S. EPA

Dave Salman	U.S. EPA

Susan Rasor	MRI

Brian Shrager	MRI

Dave Ellison	American National Can Co.

Howard Hofmeister	Curwood-Bemis

Patti Powell	Formica

Cindy Brown	International Paper

Emil Studinka	NEMA - Wilsonart Intn'l

Mark Hawes	Shurtape Technologies

Dave Meily	Konica

David Pasquini	NAPM

Peter Connery	NAPM

Alexander Ross	Rad Tech

Dennis Redding	Duralam, Inc.

Gordon Miller	Rexam Inc.

Jeffery L. Rezin	O'Sullivan/CFFA

Tomas A. Loredo	Reynolds Metals Co.

Steve Rach	Grace Tec Systems

Sarah Rice	Flexible Packaging Assoc.

Michael Wax	ICAC

Dhuanne Dodrill	Rollprint

Nathan C. Coll	Athol Corp.

Michelle Smith

Mark Wygonik	Flexible Packaging Assn.

Tim Owens	MACtac (PSTC)

Teleconference Participants:

Name	Affiliation

Janet Bowen	U.S. EPA - Region I

Bernette Schilling	NY Dept. Of Environmental Conservation

Brent Marable	U.S. EPA - Region V

Sarah Miller	U.S. EPA - Region V

OnSoon Berglund	MN Pollution Control Agency

Matthew Maik	Chicago Dept. of the Environment

Kevin Barnett	Alcoa

Bill Franek	Cook County, IL

Bruce Nicholson	NEMA / Erler and Powers

Rob Kaufman	AF&PA

Chip Dunne	Monsanto

Greg Moeller	Eastman Kodak

James G. Votaw	CFFA /Cleary, Gottlieb, Steen & Hamilton

Dale Kalina	R.R. Donnelley & Sons Company

Attachment B - Text Version of Overheads and Handouts.

Paper and Other Web Coating:

Stakeholder PMACT Meeting January 30, 1997

1) AGENDA

Introductions

Overview of Presumptive MACT

Reasons for developing PMACT

Section 112(g) requirements

PMACT Options Considered for Paper and Other Web Coating

Available data

Existing standards for paper and other web coating

Existing standards for similar industries

Regulatory Subgroup's PMACT Recommendation

Rationale and Outstanding issues

2) AGENDA continued...

Industry Input

Questions, comments, concerns

From PMACT to MACT

Industry surveys

Role of MACT partnership members

Project Schedule

Questions and Comments

Other?

3) PRESUMPTIVE MACT (PMACT)

Estimate of MACT based on readily available data

PMACT should be at least as stringent as MACT floor

PMACT is not legally binding

Developed from recommendation of regulatory subgroup (EPA, State and local agencies) with input from all stakeholders (industry and environmental representatives)

4) WHY DEVELOP PMACT?

Assist State and local agencies in making case-by-case MACT determinations under Section 112(g) or 112(j) of Clean Air Act.

For this industry, case-by-case MACT determinations will likely be restricted to constructed or reconstructed major sources under Section 112(g)

PMACT helps to define issues and identify data gaps so that additional data gathering can be focused in specific areas

5) SECTION 112(g) OVERVIEW

Final rule published in Federal Register on 12/27/96

Applies to constructed and reconstructed sources not yet covered by rules developed under Section 112(d), does not apply to modifications

Case-by-case MACT determinations are made by State and/or local agencies with approved Title V programs

Case-by-case MACT should be equivalent to new source MACT

6) 112(g) Constructed Major Source

newly constructed major source at greenfield site

newly constructed process or production unit, which is itself a major source, at existing site (unless alternative criteria are met)

7) 112(g) Reconstructed Major Source

replacement of components at existing process or production unit that is itself a major source when: component capitol costs exceed 50% of capitol cost to construct comparable unit; and technically and economically feasible for source to meet MACT

8) POTENTIAL INFORMATION SOURCES FOR USE IN DEVELOPING PMACT

Existing Federal, State, and/or local regulations for the source category; NESHAP developed for similar sources; Existing test reports; Literature searches; and Permits

9) PMACT OPTIONS CONSIDERED FOR PAPER AND OTHER WEB COATING

Printing and Publishing NESHAP and Magnetic Tape NESHAP

95 percent overall control or coatings with no more than 0.2 kg HAP/kg solids (Printing and Publishing) or 0.18 kg HAP/liter coating solids (Magnetic Tape)

Pressure Sensitive Tape NSPS

90 percent overall control, permanent total enclosure with 95 percent overall control, or coatings with no more than 0.2 lb VOC/lb solids

10) PMACT OPTIONS Continued...

Flexible Vinyl and Urethane Coating and Printing

85 percent overall control or coatings with no more than 1.0 lb VOC/lb solids

Existing data

reported capture and control efficiencies from available data (see Table 1)

11) SOURCES OF EXISTING DATA FOR PAPER AND OTHER WEB COATING

Test reports from EPA's STIRS data base; Title V permit applications; Site visits; Meetings with industry groups; and TRI data base

Table 1: Readily Available Existing Data for Paper and Other Web Coating Facilities

Capture

Efficiency	Destruction/

Removal

Efficiency	Overall

Control

Efficiency

Product Manufactured
100	99.9	99.9	Color cards for print manufacturers
100	99	99	pressure sensitive tape (PST)
100	98.8	98.8	Paper products
100	98.5	98.5	Metallized paper products (MPP)
100	98.5	98.5	MPP
100	98.5	98.5	MPP
100	98	98	Microfilm/ presentation media
100	97	97	PST
100	96.5	96.5	PST
98.1	98.2	96.3	PST
-	-	96	Microfilm/ presentation media
99.6	95.4	95	Flexible packaging (FP)
100	94.2	94.2	Not specified (NS)
98	96	94	PST
94.9	98.8	93.8	Coated fiberglass
95	98.5	93.6	MPP
-	-	93.1	Microfilm/ presentation media
99	94	93.1	PST
93.5	99	92.6	NS
-	-	91.7	Window films/ graphic arts
-	-	91.7	Window films/ graphic arts
90.9	99.7	90.6	Carbonless business forms
94.9	95	90.2	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
-	-	90	PST
91	98.2	89.4	PST
100	87.8	87.8	PST
90.7	95.3	86.4	NS
89	94.4	84	FP
-	-	81	PST
-	-	81	PST
83.4	97	80.9	PST
79.9	94.6	75.6	Coated fiberglass
90.6	83.2	75.4	PST
60.8	99	60.2	NS
55	97	53.4	NS

12)	ANALYSIS: PRESSURE SENSITIVE TAPE & FLEXIBLE VINYL COATING NSPS

Advantages: developed specifically for two major industry groups in paper and other web coating industry

Disadvantages: NSPS were developed in early 80's, so they may not be representative of current level of control

MACT floor may be more stringent than NSPS requirements

13) ANALYSIS: PRINTING AND PUBLISHING; AND MAGNETIC TAPE NESHAP

Advantages: level of control for web coating is likely to be similar (processes are similar to paper and other web coating processes; some facilities print and coat on lines using common control equipment)

More recent than NSPS and, therefore, more likely to reflect current level of control

Disadvantages: NESHAP are not specific to this source category

14) ANALYSIS: EXISTING DATA

Advantages: data are from sources likely to be covered by paper and other web coating NESHAP; Process mirrors MACT development; Reflects controls used in practice by industry

Disadvantages: data are limited and, therefore, may not be representative of entire industry; Lack of documentation for reported capture efficiency values

15) ISSUES RAISED BY REGULATORY SUBGROUP

Limited existing data

Concern with using rules since existing data suggest more stringent MACT floor

Concern over need for permanent total enclosures

Lack of data for pollution prevention alternative (e.g., equivalent coating limit)

Lack of data on controls for other emission sources

16) Response to Limited existing data

The objective of PMACT is to use "readily available" data understanding the limitations to this approach

Data gaps are identified and filled throughout MACT development

17) Response to concern over using limits in existing rules

Utilize existing limits in NSPS and NESHAP as a reality check only

Supplement existing limits with data on controls practiced by industry

18) Response to concern over need for permanent total enclosures

To meet recommended overall control efficiency, a PTE is likely to be needed

subgroup does not see this as a problem for new sources

subgroup reports conflicting data on retrofitting existing lines

many case studies of successful line/room/building PTE retrofits; some concern expressed by individual facilities regarding feasibility; however, existing lines not likely to be subject to case-by-case MACT

Other compliance options need to be considered

19) Response to lack of data for equivalent coating limit

An example calculation for a potentially equivalent coating limit is provided: coating with 3.5 kg organic solvent per kg solids (highest of 0.6 to 3.6 range) was subjected to overall control efficiency of 95 to 99; assuming all solvent is HAP the coating limit ranges from 0.18 to 0.04 kg HAP/kg solids

Encourage case-by-case MACT determinations in consideration of compliant coatings or combination of low HAP coating and controls

20) Response to lack of data on controls for other emission sources

Encourage case-by-case MACT determinations in consideration of work practices which limit emissions from other sources

Potential sources of information: MACT data base, ORD reports, existing regulations for similar sources

21) REGULATORY SUBGROUP'S DRAFT PMACT RECOMMENDATION

Suggested overall control efficiency of 95-99 percent

confident that greater than 95 percent can be achieved, but not on what higher limit should be

Pollution prevention options should be considered, but no supporting data available to establish equivalent coating limit

Control of other emission sources (e.g., cleaning, mixing, storage, wastewater) should be considered, but no supporting data for control options.

22) RATIONALE FOR PMACT RECOMMENDATION

Consistent with best performing sources in existing data base: PTE's with oxidizers and carbon adsorbers most common

Reasonably consistent with MACT for printing and publishing and magnetic tape (most recently developed standards for similar sources)

PMACT recommendation does not include precise overall control efficiency value due to limits of existing data base.

23) ADDITIONAL DATA NEEDS FOR DETERMINING MACT

Coating formulation data to develop pollution prevention alternative

Additional data on destruction, removal and capture efficiencies in practice at web coating facilities to develop overall control efficiency value

Facility wide data for evaluating potential of including facility wide average as compliance option

Data on other emission sources such as cleaning, storage, mixing, wastewater, substrate formation, etc..

24) COLLECTING DATA TO DEVELOP MACT AND COMPLIANCE OPTIONS

Information collection requests (surveys) of facilities which apply coating to paper and other webs

Surveys will include questions on: coating line configurations, including line speed, exhaust rates, etc.; coating formulation data; destruction/removal and capture efficiency values for control equipment; facility-wide emission rates; emissions and control measures for sources other than coating

25) USES FOR SURVEY DATA

Develop MACT floor

Identify potential subcategories

Develop model plants

Develop cost and environmental impacts for MACT floor and alternatives beyond the floor

Consider alternative compliance options

26) STATUS

Final PMACT determination anticipated in next couple of months

Conducted meetings with industry groups to gather specific information on industry segments (more scheduled)

Conducted site visits to gather more detailed information (more are likely)

Some surveys have been sent out others will follow

27) STATUS Continued...

Developing data base to manage survey data

Anticipate completion of data gathering by year end

MACT floor calculations early 1998

Compliance options early to mid 1998

Model plants and economic impact analysis mid-late 1998

Proposed rule 1999

Promulgated rule 2000

28) And don't forget we will also be looking at VOC emissions

Under Section 183(e) of the Clean Air Act we need to reduce volatile organic compound emissions from consumer and commercial products

Web coatings are commercial products and we will be evaluating control options fro VOC in parallel with MACT

Must develop regulation with best available controls (BAC) or issue control techniques guidelines (CTG) in lieu of regulation

Attachment 2

Summary of Solvent-Based to Waterbased

Adhesive-coated Substrate Retrofitc

Storage, Transfer, and Pumping Equipment

Because waterborne adhesives will freeze if stored outside, bulk storage containers for coatings that are located outside will either have to be moved inside or fitted with a heat jacket to maintain the coating at an acceptable temperature. The solids in waterborne adhesives, which are dispersed in the water, are more likely to settle than the solids in solventborne coatings, which are in solution in the solvent. Therefore, storage tanks will have to be equipped with agitation equipment that may not be required when using solventborne adhesives.

Waterborne coatings require water-resistant pumps, motors, and piping, e.g., PVC or stainless steel. Because waterborne adhesives typically have a higher solids content than solventborne, power consumption and wear on motors and bearings may be higher than for solventborne coatings. Stainless steel may be required for pipings, pumps, and reservoirs because of the corrosion caused by waterborne coatings.

Application Equipment

Existing application equipment can be used for many waterborne coatings. The waterborne coatings will have to be formulated with defoamers and surfactants that may not be necessary for solventborne coatings, but such formulations are available and being used and applied with the same types of application equipment that are commonly used with solventborne coatings. Waterborne coatings can and have been applied with reverse roll coaters and gravure coaters. Waterborne coatings may require a different configuration of rollers because they do not penetrate substrate surfaces as well as solventborne coatings, but again, this is a problem that can be overcome.

Drying Oven

The same ovens can be used for drying waterborne and solventborne coatings. Typically, more energy is required to dry waterborne coatings because water has a higher heat of vaporization. Drying may require either higher temperatures or longer residence times. Longer residence times can reduce production or result in increased capital costs from the installation of longer ovens.

Attachment 3

Summary of Pollution Prevention Measures

for Cleaning Operationsd

Cleanup Avoidance

Facilities may reduce the amount of cleanup required by scheduling their production run so that similar products requiring similar coatings are run in sequence. This will reduce the need to clean reservoirs, application rollers, and other equipment.

Best Practices

Facilities may be able to reduce cleaning solvent usage by restricting operator access to the solvent. Operators often use more solvent than they need for cleaning because there is no restriction on the amount they can use. Requiring operators to "check out" a limited amount of cleaning solvent per shift has been effective at some facilities in reducing usage.

Cleaning solvent usage may also be reduced by dry cleaning the equipment prior to using solvent. Coating that has adhered to application heads, rollers, and troughs may be scraped so that excess coating is removed before solvent is used.

Centralized cleaning areas may also be an effective way of reducing emissions from cleaning of parts that can be removed from machinery. Air emissions from cleaning are more easily controlled by using a ventilation system to collect the solvent- saturated air.

Recycling of Solvents and Cleaning Materials

Some facilities recover solvent using batch distillation units. Spent solvent is collected and stored and then sent to the distillation system. The solvent recovered from the distillation is then reused.

Used solvent can often be used for an initial cleaning followed by cleaning with clean solvent (either recycled or virgin) to remove any remaining material.

Alternative Cleaning Materials

Alternative cleaners may reduce HAP emissions, and in some cases, VOC emissions. Mineral spirits, which typically contain only small quantities of HAP, may be substituted for toluene and MEK, which are both HAP. Some surface coating facilities have tried using citrus based and terpene cleaners such as d-limonene and n-methylpyrrolidone as replacements for MEK and toluene. However, these materials are expensive, typically do not clean as well as traditional solvents and have a strong, undesirable odor. It is important to evaluate alternative cleaning materials carefully before switching to these materials. If mineral spirits are less effective than MEK, the facility will have to use more mineral spirits than MEK to clean the equipment properly. The facility may have lowered their HAP emissions but actually increased their VOC emissions.

Equipment Modifications

Process equipment may be modified to reduce the possibility of splashes and spills by adding edge guards and shields, thereby reducing the frequency of cleaning that is required. Rollers may be coated with nonstick materials such as teflon, silicone, or plasma-coatings, which allow the adhesive-coated substrate to pass over the roller without sticking or leaving adhesive on the roller. This will also reduce cleaning frequency. However, these coated rollers are not as durable as rollers that have not been coated. When the nonstick coating is nicked or scraped, it loses its effectiveness.

Cleaning can also be avoided by surface wrapping the outside of equipment or covering the floor surrounding the application equipment with off-specification substrate material. In this case, however, it is necessary to evaluate the quantity of solid waste generated in relation to the reduction in emissions from cleaning.

Ultrasonic Cleaning

Ultrasonic cleaning is used to clean metal parts. It involves the use of sound waves in an aqueous solution to create tiny bubbles which implode and scrub the part clean. Ultrasonic cleaning is fast, operating costs are low, and parts are thoroughly cleaned. However, capital costs can range from $100,000 to $150,000 and selecting a suitable cleaning solution can be time consuming.