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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: February 15, 2011

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

Guidelines for Flat Wood Paneling Surface Coating Processes

/s/

FROM: Irene Shandruk, Physical Scientist 

Office of Air Program Planning 

TO: File

/s/

THRU: Cristina Fernandez, Associate Director 

Office of Air Program Planning

A. BACKGROUND 

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 control techniques 

guidelines (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. 

CTGs are intended to provide state and local air pollution control authorities information that 

should assist them in determining RACT for VOCs from various sources, including flat wood 

paneling surface coating processes. In developing these CTGs, EPA, among other things, 

evaluated the sources of VOC emissions from this 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 VOCs from flat wood 

paneling surface coating processes.

In June 1978, EPA published a CTG for flat wood paneling coatings (EPA-450/2-78-034). This 

CTG discusses the nature of VOC emissions from this industry, available control technologies 
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for addressing such emissions, the costs of available control options, and other items. EPA also 

published a national emission standard for hazardous air pollutants (NESHAP) for surface 

coating of wood building products, including flat wood paneling in 2003 (40 CFR part 63, 

subpart QQQQ).

In 2006 and 2007, after conducting a review of currently existing state and local VOC emission 

reduction approaches for this industry, reviewing the 1978 CTG and the NESHAP for this

industry, and taking into account the information that has become available since then, EPA 

developed a new CTG for surface coating of flat wood paneling, entitled Control Techniques 

Guidelines for Flat Wood Paneling Coatings (Publication No. EPA 453/R-06-004).

Description of Flat Wood Paneling Coatings

Flat wood paneling coatings means wood 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.

Flat wood paneling, like most wood products, are vulnerable to light, moisture and insects. 

Coatings are used for three 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 VOCs 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 VOCs within the coating evaporate into the air.

Emissions of VOCs from flat wood coating facilities occur primarily at the coating line, although 

some emissions also occur at paint mixing and storage areas. To assist facilities and regulatory

agencies in estimating emissions, VOC emission factors for conventional solvent based coatings 

applied to interior printed panels are as follows (expressed as kilograms of VOCs per 100 square

meters (m2) coated): 3.0 for filler, 0.5 for sealer, 2.4 for basecoat, 0.3 for inks, and 1.8 for 

topcoats.

EPA’s Recommended Control Options for Flat Wood Paneling Coatings

EPA issued a CTG for flat wood paneling coatings in September 2006 (Publication No. EPA 

453/R-06-004). Recommendations for controlling VOC emissions from flat wood paneling

coatings are outlined in the CTG and are as follows:

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. These 

limits are expressed in different units but are equivalent. 
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A. Emissions Limits 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 

grams (g) VOC/l (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 

g of VOC per liter solids (2.9 lb of VOC per gal of solids). The default VOC density used for 

making this conversion was 0.88 kg/l (7.36 lb/gal).

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 above, a 

facility could choose to use add-on control equipment to meet an overall control efficiency of 90 

percent. Add-on devices include oxidizers and solvent recovery systems, which coupled with 

their attendant systems to capture the VOC being released at the affected facilities, can achieve 

an overall control efficiency of 90 percent. This control option, like the low VOC material 

option noted above, applies to surface coatings, inks, and adhesives applied to all types of flat 

wood paneling. 

C. Work Practices: Recommended work practices 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.

Table 1: Recommended Emission Limits for Flat Wood Paneling Operations

Surface Coatings, Inks, or 

Adhesives Applied to the 

Following Flat Wood Paneling 

Categories

Should Meet One of These Emission Limits

lb VOC/ gal 

material (g VOC/ 

liter material) 

[excluding water 

and exempt 

compounds]

lb VOC/ gal 

solids (g VOC/ 

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%

Tileboards 2.1 (250) 2.9 (350) 90%

Exterior siding 2.1 (250) 2.9 (350) 90%
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B. STATE SUBMITTAL

On January 4, 2011, Pennsylvania Department of Environmental Protection (PADEP) submitted 

to EPA a SIP revision concerning the adoption of the EPA flat wood paneling surface coating 

processes CTG. EPA develops CTGs as guidance on control requirements for source categories. 

States can follow the CTGs or adopt more restrictive standards. The Commonwealth of 

Pennsylvania has adopted EPA’s CTG standards for flat wood paneling surface coating 

processes. These regulations are in 25 Pa. Code Chapter 121— General Provisions and in 

Chapter 129— Standards for Sources. Specifically, this revision amends the existing regulations 

at §§ 121.1, 129.51 and 129.66, and adds new § 129.52c. Section 129.52c, which covers control 

of VOC emissions from flat wood paneling surface coating processes, supersedes the 

requirements of a RACT permit issued to the owner or operator of a source subject to § 

129.52(c)(a) prior to January 1, 2012 under §§ 129.91 – 129.95 to control, reduce, or minimize 

VOC emissions from a flat wood paneling surface coating process, except to the extent the 

RACT permit contains more stringent requirements.

Chapter 121: General Provisions

Section 121.1: Definitions

 Definitions for the following terms are added to support the addition of § 129.52c: 

“Class II hardboard paneling finish,” “decorative interior panel,” “engineered wood panel 

product,” “exterior siding,” “exterior trim,” “flat wood paneling coating,” “flat wood 

paneling product,” “hardboard,” “hardwood plywood,” “MDF—medium density

fiberboard,” “natural-finish hardwood plywood panel,” “particleboard,” “premium 

interior wall paneling product,” “plywood,” “printed interior panel,” “thin particleboard,” 

“tileboard” and “waferboard.”

Chapter 129: Standards for Sources – Sources of VOCs

Section 129.51: General

 Section 129.51(a) is amended to extend its coverage to flat wood paneling surface coating 

processes. Section 129.51(a) also provides an alternative method for owners and 

operators of facilities to achieve compliance with air emission limits.

Section 129.52c: Control of VOC emissions from flat wood paneling surface coating processes

 This section includes VOC emission limits, work practices, and recordkeeping and 

reporting requirements, all of which are consistent with EPA’s CTG for flat wood 

paneling surface coating processes. The requirements in section 129.52c supersede the 

requirements in 129.52 relating to control of VOC emissions from flat wood paneling

surface coating processes beginning January 1, 2012. 

 Subsection (a) establishes applicability for the emission limits. The emission 

limits apply to the owner or operator of a flat wood paneling surface coating 

process if the total actual VOC emissions from all flat wood paneling surface 

coating operations at the facility are equal to or greater than 15 pounds (6.8 

kilograms) per day, before consideration of controls. 

 Subsection (b) explains that the requirements of section 129.52c supersede the 

requirements of a RACT permit from a flat wood paneling surface coating
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operation already issued to the owner or operator subject to section129.52c

unless the RACT permit contains more stringent requirements.

 Subsection (c) establishes VOC emission limits which take effect beginning 

January 1, 2012. The emission limits are shown in Table 2.

Table 2: Emission Limits of VOCs for Flat Wood Paneling Surface Coatings

Surface Coatings, Inks, or Adhesives 

Applied to the Following Flat Wood 

Paneling Categories

Should Meet One of These Emission Limits

lb VOC/ gal coating 

solids

g VOC/ liter coating 

solids

Printed interior panels made of 

hardwood, plywood, or thin particleboard

2.9 350

Natural finish hardwood plywood panels 2.9 350

Class II finishes on hardboard panels 2.9 350

Tileboards 2.9 350

Exterior siding 2.9 350

 Subsection (d) establishes compliance monitoring procedures and identifies 

daily records that must be kept in order to demonstrate compliance.

 Subsection (e) establishes recordkeeping and reporting requirements.

 Subsection (f) explains that VOCs may not be emitted into the atmosphere 

from the application of flat wood paneling surface coatings, unless the 

coatings are applied using one or more of the following coating application 

methods:

1. Offset rotogravure coating

2. Curtain coating

3. Direct roll coating

4. Reverse roll coating

5. Hand brush or hand roller coating

6. High volume—low pressure (HVLP) spray coating

7. Airless spray coating

8. Air-assisted airless spray coating

9. Electrostatic coating

 Subsection (g) exempts coatings which are used exclusively for determining 

product quality and commercial acceptance if the quantity of coating used 

does not exceed 50 gallons per year for a single coating and a total of 200 

gallons per year for all coatings combined for the facility and if the owner or 

operator of the facility requests this exemption in writing and PADEP 

approves, in writing, the exemption prior to use of the coating.

 Subsection (h) establishes work practice requirements for coating-related 

activities.

 Subsection (i) establishes work practice requirements for cleaning materials.

Section 129.66: Compliance schedules and final compliance dates

 This section is amended by establishing a 1-year compliance date for owners or 

operators of a source newly subject to section 129.52, the existing surface coatings 
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regulation, as a result of revised applicability requirements. The amendment is 

intended to ensure that this flexibility is extended to owners and operators of sources 

newly subject to the expanding collection of surface coating regulations resulting 

from this CTG rulemaking, as well as three other CTG rulemakings, namely the large 

appliance, metal furniture, and paper, film and foil surface coating processes. The 

amendment will allow compliance for sources newly subject to the requirements 

within 1 year or by the compliance date specified in the new regulation, whichever is 

later.

C. EPA EVALUATION

PADEP has adopted the standards and requirements of the CTG for flat wood paneling surface 

coating processes and is amending the Pennsylvania SIP to reflect these amendments. The 

maximum benefit from these amendments will be provided during the ozone season when VOCs 

readily combine with nitrogen oxides (NOx) to form ground-level ozone. Specifically, a 

maximum range of about 5 to 21 tons of additional annual VOC emission reductions are 

anticipated from the flat wood paneling surface coatings facilities in Pennsylvania as a result of 

this rulemaking. Therefore, this revision will help Pennsylvania attain and maintain the National 

Ambient Air Quality Standards (NAAQS) for ozone. 

D. CONCLUSIONS AND RECOMMENDED AGENCY ACTION

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

the Commonwealth of Pennsylvania will result in the reduction of VOC emissions from flat 

wood paneling surface coating processes. EPA’s approval of the SIP revision is recommended.