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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: December 7, 2010

SUBJECT: Technical Support Document for Maryland’s Adoption of Control Techniques 

Guidelines (CTG) for Flat Wood Paneling Coatings 

FROM: Gregory Becoat, Environmental Scientist /s/

Office of Air Program Planning 

TO: File

THRU: Marilyn Powers, Acting Associate Director /s/

Office of Air Program Planning

A. BACKGROUND 

What is the flat wood paneling coating CTG?

Section 172(c)(1) of the Clean Air Act (CAA) provides that state implementation plans (SIPs) for 

nonattainment areas must include reasonably available control measures (RACM), including 

reasonably available control technology (RACT), for sources of emissions. Section 182(b)(2)(A) 

provides that for certain nonattainment areas, States must revise their SIPs to include RACT for 

sources of volatile organic compound (VOC) emissions covered by a CTG document issued after 

November 15, 1990 and prior to the area’s date of attainment. 

The United States Environmental Protection Agency (EPA) defines RACT as “the lowest 

emission limitation that a particular source is capable of meeting by the application of control 

technology that is reasonably available considering technological and economic feasibility.” (44 

FR 53761, Sept. 17, 1979). In subsequent Federal Register notices, EPA has addressed how 

states can meet the RACT requirements of the CAA. 

The CTG for flat wood paneling coatings is intended to provide state and local air pollution 

control authorities information that should assist them in determining RACT for VOCs from flat 

wood paneling coating. In developing this CTG, EPA, among other things, evaluated the sources 

of VOC emissions from the flat wood paneling coating industry and the available control 

approaches for addressing these emissions, including the costs of such approaches. Based on 

available information and data, EPA provides recommendations for RACT for flat wood 
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paneling coating.

In June 1978, EPA published a final CTG for flat wood paneling coatings, entitled “Control of 

Volatile Organic Emissions from Existing Stationary Sources, Volume VII, Factory Surface 

Coating of Flat Wood Paneling,” EPA-450/2-78-034 (June 1978).1In September 1979, EPA 

published guidance to provide assistance to State and local air pollution control agencies in 

preparing RACT regulations for a variety of categories, including flat wood paneling. In 2003, 

EPA promulgated national emission standards for hazardous air pollutants (NESHAP) covering 

surface coating of wood building products (including flat wood paneling). See 68 FR 31746 

(May 28, 2003).

What is flat wood paneling coatings?

Flat wood paneling products are used in construction and can be classified as three main product 

types: decorative interior panels, exterior siding, and tileboard. Flat wood paneling, like most 

wood products, are vulnerable to light, moisture and insects. Coatings are used for three principal 

purposes: protection, appearance, and surface modification. Surface coatings are applied to 

reduce potential damage from environmental elements such as moisture and temperature 

extremes and other climate-related hazards and from insect infestation. Coatings are also applied 

to enhance surfaces to make other coatings more effective. Finally, coatings are applied to 

improve the appearance of the wood product. Releases of VOC occur during the coating process 

as the coatings are mixed or thinned, as they are applied to the substrate, and as they dry and the 

VOC within the coating evaporate into the air. 

A typical flat wood coating facility applies stains and varnishes to natural plywood panels used 

for wall coverings. Other plants print wood grain patterns on particle board panels that were first 

undercoated with an opaque coating to mask the original surface. Coatings applied to flat wood 

paneling include fillers, sealers, “groove” coats, primers, stains, basecoats, inks and topcoats. 

Most coatings are applied by direct roll coating. Filler is usually applied by reverse roll coating. 

The offset rotogravure process is used where the coating and printing operation requires 

precision printing techniques. Other coating methods include spray techniques, brush coating 

and curtain coating. A typical flat wood paneling coating line includes a succession of coating 

operations. Each individual operation consists of the application of one or more coatings 

followed by a heated oven to cure the coatings. A typical production line begins with mechanical 

alterations of the substrate (filling of holes, cutting of grooves, sanding, etc.), followed by the 

coating operations, and packaging/stacking for shipment.

This CTG applies to facilities that apply flat wood paneling coatings that emit at least 6.8 kg/day

(15 lb/day) of VOC before consideration of controls. Flat wood paneling coatings means wood 

 

1 Control of Volatile Organic Emissions from Existing Sources - Volume VII: Factory Surface 

Coating of Flat Wood Paneling. Publication No. EPA-450/2-78-032. U. S. Environmental 

Protection Agency, Research Triangle Park, NC. June 1978. 
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paneling products that are any interior, exterior or tileboard (class I hardboard) panel to which a 

protective, decorative, or functional material or layer has been applied.

There are several approaches to reducing VOC emissions from flat wood coating facilities: (1) 

the use of low-VOC, waterborne coatings, (2) the use of ultraviolet cure and electron beam cure 

coatings, (3) adding/improving add-on controls, and (4) the implementation of work practice 

standards. 

EPA’s Recommended Emissions and Control Options for Flat wood Paneling Coatings

EPA issued a CTG for Flat wood Paneling Coatings on June 1978 (EPA-450/2-78-034). EPA 

recommended emission limits for the inks, coatings and adhesives used by the flat wood paneling 

coating facilities and work practices for cleaning materials used. The recommended emission 

limits for inks, coatings, and adhesives can be achieved either by using materials with VOC 

contents low enough to achieve the limits during application, or by reducing the amount of VOC 

emitted through the use of add-on controls. There are two alternative limits recommended for

the use of low VOC inks, coatings and adhesives. Table 1 summarizes the VOC emission limits 

recommended in this CTG.

A. Emissions Limit based on Low-VOC Coatings for Inks, Coatings and Adhesives 

The low-VOC materials recommendation for inks, coatings and adhesives include an emissions 

limit of 250 g VOC/liter (2.1 lb VOC/gal) of material (minus water and exempt compounds). An 

equivalent limit, expressed as units of weight of VOC per volume of solids in all coatings is 350 

grams of VOC per liter solids (2.9 lb of VOC per gal of solids). 

B. Optional Add-On Controls for Inks, Coatings and Adhesives 

Should product performance requirements or other needs dictate the use of higher-VOC coatings 

than specified in Table 1, a facility could choose to use add-on control equipment to meet an 

overall control efficiency of 90 percent. 

C. Work Practices 

The recommended work practice plan include steps to ensure that VOC emissions are minimized 

from mixing operations, storage tanks and other containers, and handling operations for coatings, 

thinners, cleaning materials, and waste materials. Examples of work practice standards include: 

storing all VOC coatings, thinners, and cleaning materials in closed containers, minimizing spills 

of VOC containing coatings, thinners, cleaning up spills immediately, conveying any coatings, 

thinners, and cleaning materials in closed containers or pipes, closing mixing vessels which 

contain VOC coatings and other materials except when specifically in use, and minimizing 

emissions of VOC during cleaning of storage, mixing, and conveying equipment.
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Table 1. Recommended Emission Limits for Flat Wood Paneling Coating Operations

B. STATE SUBMITTAL

On April 23, 2010, Maryland Department of the Environment (MDE) submitted to EPA a SIP 

revision concerning the adoption of the EPA CTG for flat wood paneling coatings. EPA 

develops CTGs to provide States with guidance on control requirements for source categories. 

States can follow the CTGs or adopt more restrictive standards. MDE is adopting EPA’s CTG 

standards for flat wood paneling coatings (see EPA-450/2-78-034, June 1978). This SIP revision 

includes new regulation .33 under COMAR 26.11.19, Volatile Organic Compounds from 

Specific Processes. This action affects facilities that apply stains and varnishes to natural 

plywood panels used for wall coverings. This SIP revision also includes amendments to 

regulation .32 under COMAR 26.11.19; however, on November 12, 2010, MDE submitted a 

letter to withdraw this portion because Maryland had not previously submitted COMAR 

26.11.19.32 to be approved as part of the SIP. 

COMAR 26.11.19.33 – Control of Volatile Organic Compounds (VOCs) Emissions from Flat 

Wood Paneling Coatings is being added:

Section .33(A): Includes definitions for the following terms pertaining to flat wood paneling 

coatings: (1) “Class II finishes on hardboard panels,” “Exterior siding,” “Flat wood paneling,” 

Surface Coatings, Inks, or 

Adhesives Applied to the 

Following Flat Wood Paneling 

Categories

Should Meet One of These Emission Limits:

lb VOC per

gallon material

(grams VOC 

per

liter material)

[excluding 

water and 

exempt 

compounds ]

lb VOC per

gallon solids

(grams VOC per

liter solids)

Overall Control 

Efficiency Using an 

Add-On Control 

Device:

Printed interior panels made of 

hardwood, plywood, or thin 

particleboard 

2.1 (250) 2.9 (350) 90% 

Natural finish hardwood plywood 

panels 

2.1 (250) 2.9 (350) 90% 

Class II finishes on hardboard panels 2.1 (250) 2.9 (350) 90% 

Tileboard 2.1 (250) 2.9 (350) 90% 

Exterior siding 2.1 (250) 2.9 (350) 90% 
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“Hardwood plywood,” “Natural finish hardwood plywood panels,” “Printed interior panels,” 

“Thin particleboard,” and “Tileboard.” 

Section .33(B): Incorporates by reference ANSI A135.5-2004, Prefinished Hardwood Paneling 

and ANSI A135.4-2004, Basic Hardboard.

Section .33(C): Describes the applicability of this regulation.

Section .33(D): Includes the requirements for flat wood paneling coating. Any person who 

applies flat wood paneling coatings, including inks and adhesives, where total precontrol VOC 

emissions from all flat wood paneling coating operations at a premises is 15 pounds or more per 

day (6.8 kg/day) shall meet the coating standards or overall control efficiency specified in Table 

1.

C. EPA EVALUATION

The State of Maryland has adopted the standards and requirements of the CTG for flat wood 

paneling coating and is revising its SIP to reflect these amendments. The maximum benefit from 

these amendments will be provided during the ozone season when VOCs readily combine with

nitrogen oxide to form ground-level ozone. Therefore, this revision will help Maryland attain 

and maintain the national ambient air quality standard for ozone. 

D. CONCLUSIONS AND RECOMMENDED AGENCY ACTION

The adoption of the EPA CTG requirements for flat wood paneling coating by the State of 

Maryland will result in the reduction of VOC emissions from flat wood coating facilities. EPA 

approval of the SIP revision is recommended.