July 2003

Emission Factor Documentation for AP-42

Chapter 10

Plywood and Composite Wood Products

Final Background Report

Prepared for

U. S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Emission Factors and Inventory Group

Research Triangle Park, NC 27711

RTI Project No. 08550.001.014.003

Prepared by

RTI International

3040 Cornwallis Road

Research Triangle Park, NC 27709

July 2003

Emission Factor Documentation for AP-42

Chapter 10

Plywood and Composite Wood Products

Final Background Report

Prepared for

U. S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Emission Factors and Inventory Group

Research Triangle Park, NC 27711

RTI Project No. 08550.001.014.003

Prepared by

RTI International

3040 Cornwallis Road

Research Triangle Park, NC 27709
ii

NOTICE

The information in this document has been funded wholly or in part by the U. S. Environmental

Protection Agency under Contract No. 68-D01079 to RTI International. It has been reviewed by the

Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency, and has been

approved for publication. Mention of trade names or commercial products does not constitute

endorsement or recommendation for use.
iii

Table of Contents

Section Page

1.0 Introduction ................................................................. 1-1

2.0 Sources of Emission Data ...................................................... 2-1

2.1 Previous AP-42 Background Reports ...................................... 2-1

2.2 Emission Test Reports from EPA MACT Survey ............................. 2-2

2.3 NCASI Data .......................................................... 2-2

3.0 Pollutants and Emission Measurement Methods .................................... 3-1

3.1 Hazardous Air Pollutants (HAP) .......................................... 3-1

3.2 Non-HAP Data ........................................................ 3-2

3.2.1 Organic Compounds ............................................. 3-2

3.2.2 Particulate Matter ............................................... 3-4

3.2.3 Other Non-HAP Compounds ...................................... 3-6

3.3 Emission Testing Issues ................................................. 3-7

3.3.1 Organic Emissions From Dryers and Presses .......................... 3-7

3.3.2 Moisture Content of Dryer Exhaust ................................. 3-7

3.3.3 VOC and PM-10 Measurements .................................... 3-8

3.3.4 Interrelationship of PM/PM-10 and VOC Emissions .................... 3-9

3.3.5 Summary of Emission Testing Issues ................................ 3-9

4.0 Review of Emission Data ...................................................... 4-1

4.1 AP-42 ............................................................... 4-2

4.2 Emission Test Reports .................................................. 4-2

4.3 NCASI Data .......................................................... 4-4

5.0 Emission Factor Calculations ................................................... 5-1

5.1 General Approach ..................................................... 5-1

5.2 Grouping of Emission Data .............................................. 5-1

5.2.1 Grouping by Air Pollution Control Device ........................... 5-1

5.2.2 Grouping Within Source Types .................................... 5-2

5.3 Calculating Emission Factors ............................................ 5-3

5.4 Emission Factor Ratings ................................................ 5-4

6.0 References .................................................................. 6-1

Attachment 1. Acronyms/Codes/Abbreviations .......................................... A-1

Attachment 2. Example Calculation .................................................. A-11

Attachment 3. Conversion Factors and Equations ....................................... A-15
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1.0 Introduction

1-1

1.0 Introduction

The purpose of this report is to document the development and revision of emission factors for

the EPA’s Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources

(commonly referred to as AP-42), Chapter 10, Wood Products Industry. Four previous AP-42 sections

were revised: Section 10.5, Plywood Manufacturing; Section 10.6.1, Waferboard/Oriented Strandboard

Manufacturing; Section 10.6.2, Particleboard Manufacturing; and Section 10.6.3, Medium Density

Fiberboard Manufacturing. In addition, two new AP-42 sections were developed: Section 10.6.4,

Hardboard and Fiberboard Manufacturing; and Section 10.9, Engineered Wood Products Manufacturing. 

Emission factors were not revised for the remaining sections of Chapter 10 (lumber, chemical wood

pulping, pulp bleaching, papermaking, charcoal, and wood preserving). 

An emission factor is a representative value that attempts to relate the quantity of a pollutant

released to the atmosphere with an activity associated with the release of that pollutant. Emission factors

usually are expressed as the weight of pollutant divided by the unit weight, volume, distance, or duration

of the activity that emits the pollutant. The emission factors presented in AP-42 may be appropriate to

use in a number of situations, such as making source-specific emission estimates for areawide inventories

for dispersion modeling, developing control strategies, screening sources for compliance purposes,

establishing operating permit fees, and making permit applicability determinations.

This background report consists of six sections. Section 1 is the introduction to the report. 

Section 2 discusses the sources of the emission data used to develop the emission factors. Section 3

discusses the pollutants and the emission measurement methods used to collect the data. Section 4

discusses the review of the emission data. Section 5 discusses the calculation of the emission factors. 

Section 6 lists the references.
1.0 Introduction

1-2

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2.0 Sources of Emission Data

2-1

2.0 Sources of Emission Data

The emission factors presented in this report are based on data combined from three types of

sources: (1) prior versions of AP-42 sections covering the plywood and composite wood products

industry; (2) numerous emission test reports (dated 1995 or later) collected from plants during EPA’s

1998 maximum achievable control technology (MACT) standard survey; and (3) results from an

extensive air emission testing program conducted by the National Council of the Paper Industry for Air

and Stream Improvement (NCASI). A total of 111 emission data sources were reviewed in the

development of emission factors for the plywood and composite wood products sections of AP-42. 

These 111 emission data sources are divided into three groups as follows:

# Background reports for the previous plywood and composite wood products industry sections

of AP-42 (including reviews of 124 emission test reports) — four reports;

# Emission test reports submitted with responses to EPA’s 1998 MACT survey — 99 reports;

and

# NCASI technical bulletins (numbers 768 through 774, dated January 1999) and an associated

database — seven bulletins and the database.

When combined, the data from these three emission data sources yielded a total of approximately

30,000 individual emission test runs. Sections 2.1 through 2.3 below provide brief descriptions of the

three data sources.

2.1 Previous AP-42 Background Reports

Emission factors for the wood products industry are presented in Chapter 10 of AP-42.1 

Chapter 10 is divided into multiple sections according to the type of wood product manufactured. For

each section published in AP-42, there is an accompanying background report. The AP-42 background

reports provide details from each of the emission data references used to develop the AP-42 emission

factors. Emission test data and process information were extracted from the background reports for the

following previous AP-42 sections:2-5

# Plywood Manufacturing (September 1997),

# Waferboard/Oriented Strandboard (OSB) Manufacturing (December 1998),

# Particleboard Manufacturing (September 1998), and

# Medium Density Fiberboard (MDF) Manufacturing (September 1998).

The previous plywood background report includes a review of emission data from five emission

test reports, NCASI Technical Bulletin No. 405, and the plywood portion of NCASI Technical Bulletin

No. 694.6,7 The previous waferboard/OSB background report includes a review of 105 emission test

reports and the OSB portion of NCASI Technical Bulletin No. 694. The previous particleboard

background report includes a review of eight emission test reports and the particleboard portion of

NCASI Technical Bulletin No. 693.8 The previous MDF background report includes a review of six

emission test reports and the MDF portion of NCASI Technical Bulletin No. 693.
2.0 Sources of Emission Data

2-2

The four previous AP-42 background reports were the source of approximately 5,600 emission

test runs. The background reports include a significant quantity of data for criteria and other nonhazardous air pollutant (HAP) emissions including various particulate matter (PM) fractions, carbon

monoxide (CO), nitrogen oxides (NOx), carbon dioxide (CO2), total hydrocarbon (THC), and 33 other

non-HAP compounds. The emission test data extracted from the AP-42 background reports also include

measurements for 32 speciated HAP compounds. The background reports include data for uncontrolled

emissions sources, as well as data for emissions controlled with a number of air pollution control devices

(APCDs), including regenerative thermal oxidizers (RTOs), wet electrostatic precipitators (WESPs),

electrified filter beds (EFBs), wet scrubbers, multicyclones (multiclones), and baghouses (fabric filters).

2.2 Emission Test Reports from EPA MACT Survey

In addition to the data from the previous AP-42 background reports, 45 plants (representing

14 companies) submitted 99 emission test reports with their responses to a 1998 EPA MACT survey of

the plywood and composite wood products industry.9-107 These 99 reports represent approximately

3,400 emission test runs and include measurements of 21 speciated HAP compounds. These reports also

include measurements of THC, CO, CO2, NOx, and 25 other non-HAP compounds. The reports include

measurements of uncontrolled emissions, as well as controlled emissions from sources equipped with

several types of APCDs including RTOs, regenerative catalytic oxidizers (RCOs), thermal oxidizers,

exhaust gas recirculation systems, biofilters, wet scrubbers, EFBs, WESPs, baghouses, and

multicyclones.

2.3 NCASI Data

Data from the NCASI MACT sampling program is published in a series of seven technical

bulletins and was also provided to EPA electronically in a consolidated emissions database.108-115 The

consolidated emissions database includes approximately 21,000 emission test runs and is the largest

single source of emission data for the wood products industry. Emission tests were conducted at

29 wood products mills, representing a cross section of product types, source types, and emission control

techniques.

The data collected from the NCASI program characterize emissions of 20 speciated HAP

compounds, 9 additional non-HAP compounds, THC, and CO. In some cases, methane emissions were

measured at RTO outlets so that non-methane THC emissions could be calculated. In addition to

uncontrolled emissions, emissions were measured at the outlets of a number of different APCDs,

including RTOs, RCOs, biofilters, wet scrubbers, WESPs, EFBs, and baghouses.
3.0 Pollutants and Emission Measurement Methods

3-1

3.0 Pollutants and Emission Measurement

Methods

A number of different emission test methods were used to collect the emission data used in the

development of emission factors for the plywood and composite wood products sections of AP-42. 

Table 1 of Attachment 1 lists each emission test method used, the test method code used in the NCASI

databases and the spreadsheets used to develop the new emission factors, and the pollutants measured

with each method. Most of the data were collected using EPA reference test methods or the NCASI

impinger/canister method (NICM). With a few exceptions, all emissions data for a given pollutant were

treated equally regardless of the test methods used to collect those data. Data collected using ambient

test methods or National Institute for Occupational Safety and Health (NIOSH) test methods were

discarded if data collected with stack sampling methods were available for the same combination of

source, control device, and pollutant. In addition, data collected using Method 25 (M25) were not used

for the reasons provided in Section 3.2.1. Emission test methods for HAP and non-HAP compounds are

discussed in the paragraphs below.

3.1 Hazardous Air Pollutants (HAP)

“Hazardous air pollutants,” as used in this report, refers to the list of pollutants as promulgated in

§112(b)(1) of the Clean Air Act (CAA). Emissions data were collected for approximately 30 HAP

compounds as part of this revision of AP-42. These HAP are italicized in Table 1 of Attachment 1. The

available HAP emissions data were collected using a variety of emission test methods.

With one exception, formaldehyde, no attempt was made to assess the potential effect of stack

sampling methods on measured HAP emissions, primarily because the data sets were too small to show

any significant effects. However, a significant amount of formaldehyde data was obtained using two

distinct test methods (described below), and therefore, the formaldehyde data collected with these two

methods were compared to determine if there were any biases associated with the test methods. The

results of the data analysis showed no discernible differences in the results obtained using the two

methods (in fact, the two data sets completely overlapped), and therefore, all of the available

formaldehyde data were treated as one data set.116

The bulk of the speciated organic HAP data (including formaldehyde) was collected as part of

the NCASI emissions test program using the NICM. The NCASI test program included the sampling and

analysis of 20 different HAP compounds. A list of these compounds and the analysis methods used to

measure each HAP is provided in Table 2 of Attachment 1. The NICM testing was done using a selfvalidating quality assurance program and is described in detail in NCASI Technical Bulletin 774.114

A significant amount of formaldehyde and other aldehyde and ketone emissions data from wood

products operations also was obtained using EPA Method 0011 (M0011). The procedure collects an

integrated sample isokinetically at points along perpendicular traverses of the stack. The gaseous and

particulate pollutants in the sample gas are collected in an impinger train that contains an aqueous acidic

solution of dinitrophenyl-hydrazine. Formaldehyde reacts with the dinitrophenyl-hydrazine to form a
3.0 Pollutants and Emission Measurement Methods

3-2

formaldehyde dinitrophenylhydrazone derivative. This derivative is extracted, solvent exchanged,

concentrated, and analyzed by high performance liquid chromatography.

Although M0011 was developed specifically for formaldehyde emissions, it has not been

validated for measuring formaldehyde emissions from wood products industry emission sources. EPA

Method 0011 also has been applied to other aldehyde and ketone compounds including acetaldehyde,

acrolein, propionaldehyde, and methyl ethyl ketone. However, EPA recommends that M0011 be used

only for the determination of formaldehyde, acetophenone, isophorone, acetaldehyde, and

propionaldehyde emissions from stationary sources.117 The EPA further concludes that M0011 is not

appropriate for the measurement of quinone, acrolein, methyl ethyl ketone, and methyl isobutyl ketone,

due either to poor collection efficiency or analytical problems. The poor collection efficiency and

analytical problems result in emission estimates for these compounds that are biased low.

Some formaldehyde data were collected using California Air Resources Board (CARB) Method

430. The EPA’s Emission Measurement Center (EMC) has indicated that this method is similar to

M0011.118

Other EPA reference methods used to collect HAP emission data include Method 0010 for semivolatile organic HAP, Method 0030 for volatile organic HAP, Method 308 for methanol, and Method 18

for benzene. In addition, three methods from the EPA Compendium of Methods for the Determination of

Toxic Organic Compounds in Ambient Air (TO) were used to collect HAP data: TO-5, TO-8, and

TO-14. The limited data available for methylene diphenyl diisocyanate (MDI) were collected using one

of two methods: the 1-(2-pyridyl) piperazine method (1,2-PP) or NIOSH Physical and Chemical

Analytical Method 142 (P&CAM142).

3.2 Non-HAP Data

Data also were compiled for a number of non-HAP compounds. The majority of the non-HAP

emission data collected are measurements taken using EPA reference methods. Emission measurement

methods for organic compounds, PM, and other non-HAP compounds are discussed in the paragraphs

which follow.

3.2.1 Organic Compounds

Organic compound emissions data for the wood products industry have been obtained primarily

via one of two EPA methods: Method 25 (M25) and Method 25A (M25A). It is important to understand

that these two methods measure different portions of the total organic compounds in the exhaust stream

and that results from the two methods are not directly comparable.

Method 25 measures volatile organic compounds (VOC) emissions as total gaseous nonmethane

organics (TGNMO). Results of M25 measurements are typically reported as carbon concentrations or

mass rates. Because organic PM interferes with the analysis of the volatile organics, the sample is drawn

through a heated filter for PM removal. The sample is drawn from the filter through a condensate trap

into an evacuated sample tank. The material in the trap and sample tank are recovered and analyzed

separately, and the results are combined to determine total VOC. The organic material in the condensate

trap is oxidized to CO2 and collected in an evacuated vessel; then a portion of the CO2 is reduced to

methane (CH4) and measured by flame ionization detector (FID). A portion of the gas collected in the

sample tank is first passed through a gas chromatograph to separate CO, CO2, and CH4 from the
3.0 Pollutants and Emission Measurement Methods

3-3

remaining nonmethane organic material (NOM). The NOM is then oxidized to CO2, reduced to CH4, and

measured by FID. This procedure essentially counts the number of carbon atoms present in the

nonmethane volatile organic material and eliminates inconsistencies associated with the variable

response of the FID to different organic compounds.

Method 25A is used to provide a continuous measure of the concentration of organic vapors

consisting primarily of alkanes, alkenes, and aromatic hydrocarbons, collectively referred to as THC. 

The stack gas sample is collected through a heated sample line with either an in-stack or heated filter to

remove PM. From the filter, the sample is directed to an FID, and the concentration of organic material

in the gas stream is measured as calibration gas equivalents or as carbon equivalents. The results depend

strongly on the particular constituents that make up the organic content of the gas stream because the FID

has different response factors for different organic bond structures. In particular, the carbon/oxygen

bond (as in formaldehyde) provides a negative interference, so the response of the FID to oxygenated

compounds (like formaldehyde) is diminished. Consequently, M25A does not include an adequate

measure of formaldehyde emissions and does not accurately quantify emissions of other oxygenated

compounds in the THC estimate. Also, M25A measures methane, which is not regulated as a VOC. This

may result in the overestimation of VOC emissions from gas-fired emission sources which may have

significant methane emissions.

The limited amount of M25 VOC emission data from the previous AP-42 background reports

was discarded. As mentioned above, measurements of VOC obtained using M25 are not directly

comparable with measurements of THC obtained using M25A. All of the non-speciated organic

compound data from the 99 emission test reports and from the NCASI MACT sampling program were

collected using M25A. In addition, most of the non-speciated organic compound data from the previous

AP-42 background reports were obtained using M25A. All THC emission factors presented in this report

are based on M25A and are reported on a carbon basis. The THC emission factors have not been

adjusted to exclude methane.

It is important to note that the THC emission factor for a given source is not directly comparable

to the sum of organic HAP emission factors (total HAP) for that source. The THC analysis uses the

molecular weight (MW) of carbon (12 grams/mole) to convert measured concentrations into mass

emission rates. The mass emission rates for the individual HAP are calculated using the molecular

weights of the individual compounds. Thus, different mass emission rates would be calculated by the

two methods even if the measured concentrations were the same. In addition, as mentioned above,

M25A underestimates the concentrations of oxygenated compounds in the exhaust stream.

Guidance from EPA’s Emission Factor and Inventory Group (EFIG) indicates that, when

possible, VOC emission factors should be reported in terms of the actual weight of the emitted

compound. However, when an actual MW of the emitted stream is not feasible (as is the case with the

mixed streams emitted from wood products industry sources), the VOC should be reported using an

assumed MW of 44, and reported “as propane.” Each VOC-as-propane emission factor is estimated by

first converting the THC from a carbon basis to a propane basis. Propane (MW = 44) includes 3 carbon

atoms (total MW of 36) and 8 hydrogen atoms (total MW of 8). Every 36 pounds of carbon measured

corresponds to 44 pounds of propane. The ratio of the MW of propane to the MW of carbon in propane

is 44/36, or 1.22. The conversion from mass on a carbon basis to mass on a propane basis is expressed

by the following equation:
3.0 Pollutants and Emission Measurement Methods

3-4

THC as pounds carbon × 44 pounds propane

36 pounds carbon = THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

After the THC emission factor has been converted from a carbon to a propane basis, the

formaldehyde emission factor is added (where available), then the available emission factors for

non-VOC compounds, including acetone, methane, and methylene chloride, are subtracted. This

procedure is expressed simply by the following equation:

VOC as propane = (1.22 × THC as carbon) + formaldehyde - (acetone + methane + methylene chloride)

In cases where no emission factor is available (or the emission factor is reported only as below the test

method detection limit, or “BDL”) for one or more of the compounds used to estimate the VOC-aspropane value, adjustments to the converted THC value are made only for those compounds for which

emission factors are available. That is, a value of zero is inserted in the above equation for the specified

compounds where no emission factor is available, or where the emission factor is reported only as BDL. 

For example, if no methane emission factor is available, the THC-as-carbon emission factor is converted

to THC-as-propane, formaldehyde is added, and only acetone and methylene chloride are subtracted.

3.2.2 Particulate Matter

There are three distinct PM fractions for which EPA has developed emission test methods: 

(1) filterable PM, (2) condensible PM, and (3) particulate matter equal to or less than an equivalent

aerodynamic diameter of nominally 10 micrometers (PM-10). The material collected in the probe and

filter (front-half catch) of an EPA Method 5 (M5) sampling train is considered by EPA to be filterable

PM. The material collected in the impingers (back-half catch) of an EPA M5 or Method 202 (M202)

sampling train is considered by EPA to be condensible PM. The material collected on the filter and in

the sample line between the cyclone and filter of an EPA Method 201 or 201A (M201 or M201A)

sampling train is considered by EPA to be PM-10.

Test methods for PM (both filterable and condensible) include the standard reference method

(EPA Methods 1 through 5 with M5 being the primary PM procedure) and derivatives of M5. Other

methods that have been used in the plywood and composite wood products industry are EPA Method 17

(M17) for total PM, M201 and M201A for PM-10, M202 for condensible PM, Oregon Department of

Environmental Quality Method 8 (ODEQ-8) for filterable PM, and the Oregon Department of

Environmental Quality Method 7 (ODEQ-7) for both filterable PM and condensible PM. The paragraphs

below first describe the essential features of M5 and then describe how the other procedures differ from

M5. No emissions data based on M17, ODEQ-7, or ODEQ-8 have been used to develop emission factors

were used to develop the revised and new wood products AP-42 sections.

The primary components of the M5 sampling train are the nozzle, the probe, a filter (which is

maintained at 120 ± 14°C [250 ± 25°F] in a heated filter box), an impinger train that is kept in an ice bath

to cool the gas stream to ambient temperature, a meter box, and a pump. The impinger train contains

four impingers; the first two contain water, the third is dry, and the fourth contains silica gel to dry the

gas stream before it enters the dry gas meter. The M5 train collects an integrated sample over one to

several hours at sample points that span a cross-section of the exhaust duct or stack, typically on

perpendicular traverses across the diameter of the stack. At each sampling point, a sample of the gas
3.0 Pollutants and Emission Measurement Methods

3-5

stream is collected isokinetically through the nozzle. The captured gas stream moves through the probe

to the filter. Some particles are collected on the walls of the probe, and the remaining material that is in

particle phase at 120°C (250°F) is collected on the filter. The gases that pass through the filter then go

through the impinger train where any organic or inorganic materials that condense between 16° and

120°C (60° and 250°F) are collected. Typically, the material collected in the probe and filter (front half

catch) is considered for regulatory purposes to be PM, and the material captured in the impingers (back

half catch) is considered to be condensible PM. The procedures for M5 do not require the back half

catch of the sampling train to be quantified. However, as explained below, the M5 train may be coupled

with a M202 sampling train for measuring the condensible PM emission rate.

The other two methods that have been used to collect total PM emissions from plywood and

composite wood products industry operations, M17 and ODEQ-7, encompass the same principles as M5

but have specific modifications. The primary difference between M5 and M17 is in the collection

temperature for the front half catch. In order to maintain a collection temperature of 120°C (250°F), the

M5 train employs a heated probe and filter. In contrast, the M17 train employs an in-stack filter, so the

collection temperature is equal to the actual temperature of the stack gas. If the stack gas temperature is

less than 120°C (250°F), then any material that condenses at temperatures between the stack gas

temperature and 120°C (250°F) will be measured as filterable PM with M17. However, in a M5 train,

this material would pass through the front half of the train to the impingers and would not be quantified

as filterable PM. The measures are reversed if the stack gas temperature is greater than 120°C (250°F).

The ODEQ-7 method modifies M5 by adding a filter between the third and fourth impingers to

collect any condensed material that escapes the impingers. This filter is maintained at approximately

ambient temperature, and the material collected in the first three impingers and on the second filter are

added to the front-half catch to obtain total PM. This procedure is intended to measure those constituents

in the emissions responsible for the formation of PM once the emissions have cooled to ambient

temperature.

Oregon Department of Environmental Quality Method 8 is a high volume method of sampling

filterable PM emissions, primarily designed for wood products handling cyclone and baghouse exhaust

systems, for which the primary emissions are solid PM. The primary components of the ODEQ-8 train

are the nozzle, the probe, a filter (unheated, outside stack), a meter box and a pump. One primary

difference between M5 and ODEQ-8 is in the collection temperature for the filter catch. In order to

maintain a collection temperature of 120°C (250°F), the M5 train employs a heated probe and filter. In

contrast, the ODEQ-8 train uses an unheated probe, and an unheated, out-of-stack filter, so the collection

temperature is near the actual temperature of the stack gas. If the stack gas temperature is less than

120°C (250°F), then any material that condenses at temperatures between the stack gas temperature and

120°C (250°F) will be measured as filterable PM with ODEQ-8. However, in a M5 train, this material

would pass through the front half of the train to the impingers and would not be quantified as filterable

PM. The other major difference between M5 and ODEQ-8 is that the Oregon method does not include a

series of impingers, or back half, and, therefore does not quantify condensible PM.

In 40 CFR Part 51, EPA has published a procedure for determining condensible PM emission

rates (M202). Method 202, which applies to determination of condensible PM from stationary sources,

measures condensible PM as material that passes through the filter and is collected in the impingers of a

PM train. The primary method specifies that condensible PM be based on the back-half catch of a M17

train (which uses an in-stack filter), but M5, M201, or M201A procedures are also acceptable. The

method specifies that the impinger solution be extracted with methylene chloride, the inorganic and
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3-6

organic fractions be dried separately, the residues weighed, and the condensible PM be determined from

the combination of both residues. Note that because the method allows the use of either a heated filter

system or an in-stack filter system, some ambiguity in results can occur from test to test.

In 40 CFR Part 51, EPA has published two procedures for determining PM-10 emission rates

(M201 and M201A). Methods 201 and 201A are derivatives of M5, both of which include an in-stack

cyclone to remove particles with an aerodynamic diameter greater than 10 micrometers (:m) from the gas

stream followed by an in-stack filter to collect the remaining particles. The back half of the train is

identical to the back half of the M5 train. Both methods require a traverse of the stack, but M201 uses

isokinetic sampling with a recirculating system to maintain constant flow through the cyclone, while

M201A uses a constant sampling rate. The PM-10 is determined gravimetrically from the material

captured in the sample line between the cyclone and filter and on the filter. Neither of the two methods

specify procedures for determining condensible PM, but both methods indicate that for applications such

as inventories of sources contributing to ambient PM-10 levels, PM-10 should be the sum of condensible

PM emissions and PM-10 emissions measured by the M201 or M201A procedures.

It is routine for filterable PM and condensible PM emissions to be summed in order to generate a

total, or “primary PM” value. With regard to PM-10 emissions, the applicability sections of EPA M201

and M201A state that:

EPA recognizes that condensible emissions not collected by an in-stack method are also

PM-10, and that emissions that contribute to ambient PM-10 levels are the sum of

condensible emissions and emissions measured by an in-stack PM-10 method, such as

[Method 201] or Method 201A. Therefore, for establishing source contributions to

ambient levels of PM-10, such as for emission inventory purposes, EPA suggests that

source PM-10 measurement include both in-stack PM-10 and condensible emissions.

In effect, this means that condensible PM emissions are also PM-10 emissions, and in order to determine

total “primary PM-10” emissions, PM-10 emissions measured with M201 or M201A should be summed

with condensible PM emissions. In this report, PM-10 emissions measured with M201 or M201A are

referred to as “filterable PM-10” as an indication of EPA’s view that these measurements represent only

the “front-half” or “dry” portion of total primary PM-10 emissions.

Separate emission factors are presented for filterable PM and condensible PM; they may be

summed to determine an emission factor for total primary PM. Similarly, the separate emission factors

presented for filterable PM-10 and condensible PM may be summed to determine an emission factor for

total primary PM-10.

3.2.3 Other Non-HAP Compounds

Data are available for CO, CO2, NOx, SO2, and a number of volatile and semi-volatile organic

compounds. As noted above, most of the non-HAP data have been collected using EPA reference

methods. Data for these non-HAP compounds are incorporated from the previous AP-42 data and from

the 99 emission test reports submitted with the MACT survey responses. 

Speciated non-HAP aldehyde and ketone data based on M0011 measurements are available,

primarily for the MDF and particleboard industry sectors. As mentioned in Section 3.1 of this report,

EPA recommends M0011 be used only for the determination of formaldehyde, acetophenone,
3.0 Pollutants and Emission Measurement Methods

3-7

isophorone, acetaldehyde, and propionaldehyde emissions.117 Due to poor collection efficiency and

analytical problems, emission estimates for other compounds may be biased low. The M0011 data for

these compounds have been used to develop emission factors only in cases where no other emission data

are available. For compounds where measurements with other methods are available, the M0011 data for

these compounds have not been used in the development of average emission factors.

 Speciated non-HAP data were also extracted from the NCASI MACT sampling database. The

NCASI MACT sampling database includes measurements of nine speciated non-HAP organic

compounds. A list of the nine non-HAP compounds and the analytical methods used to measure each

compound is provided in Table 3 of Attachment 1. The NCASI MACT sampling database also includes

measurements of CO and methane at selected sources.

3.3 Emission Testing Issues

Many of the difficulties encountered in developing VOC and PM-10 emission factors for

plywood and composite wood products industry dryers and hot presses arise because of the chemical

composition of the organic materials found in the emission streams from these processes and the use of

different test methods to collect and analyze these organic compounds for the historical data base. Also,

the chemical and physical characteristics of these emission streams, particularly the moisture content and

temperature variations, complicate sampling and analysis and data reduction. Particular issues of

concern are complications associated with high moisture in exhaust streams, differing VOC and PM-10

results from different procedures and associated concerns with the condensible PM-10 as measured by

Method 202, and the interrelationship between the estimates of VOC and PM-10 emissions. These issues

are a general concern in the wood products industry and should be considered in the planning of emission

test programs for the industry. The paragraphs below first discuss the characteristics of the organic

material in wood products exhaust streams and then address the general issues outlined above.

3.3.1 Organic Emissions From Dryers and Presses

As green wood is subjected to heat in plywood and composite wood products dryers, some of the

organic material in the wood is volatilized and carried off with the exhaust stream. These organic

materials that emanate from the wood are the primary VOCs and condensible organic PM in the dryer

exhaust. Consequently, the organic compounds found in wood products dryer emissions typically

include terpenes, terpene-like materials, resins, and fatty acids comparable to those found in wood. The

boiling points of many of these materials are in the range of 155° to 370°C (310° to 700°F). These

temperatures are greater than typical dryer temperatures for some industry sectors, but the compounds

exhibit significant vapor pressures at dryer temperatures. Consequently, some of these organic

compounds are at saturation levels in the gas streams and will condense as the gas stream cools.

3.3.2 Moisture Content of Dryer Exhaust

The inherent moisture contents of exhaust streams from plywood and composite wood products

dryers complicate measurement of PM-10 emissions in these streams. This problem is most prevalent for

facilities that have wet control devices such as wet ESPs or wet scrubbers. Because the exhaust from

these systems is saturated, moisture condensation downstream from the control device is common. The

EPA reference methods for PM-10 prescribe an in-stack filter that operates at stack temperatures. If the

gas stream contains water droplets, sample train filter blinding (blockage of gas flow through the filter) is

likely to preclude PM-10 sampling. This problem has been encountered during EPA tests conducted on
3.0 Pollutants and Emission Measurement Methods

3-8

wet ESP-controlled dryers as a part of the program to develop emission factors for the wood products

industry.

One solution to this problem is to use a heated filter rather than an in-stack filter in the

Method 201 or 201A train. As a part of the testing, Method 202 could be used to determine condensible

PM emissions from the back half of the Method 201 or 201A train. The total PM-10 emissions could be

estimated as the sum of the PM-10 emissions obtained from Method 201 or 201A and the condensible

PM emissions obtained from Method 202. This solution will eliminate the moisture problem, but it does

have two drawbacks. First, since this procedure is different from the procedure used for dry control

systems, the results will not be directly comparable. Second, this procedure exacerbates the problems

related to the interrelationship of VOC and PM-10 emissions discussed below.

High levels of moisture in exhaust streams can cause negative bias on Method 25A THC

measurements. The magnitude of the bias can differ for different Method 25A analyzers. Few analyzers

have shown significant biases at moisture contents of less than 10 percent. However, significant negative

bias (e.g., around 20 percent) has been shown to occur for some Method 25A analyzers at 20 percent

moisture. One method for preventing the negative bias is to dilute high moisture exhaust streams to less

than 10 percent moisture using heated air.

3.3.3 VOC and PM-10 Measurements

As suggested by the characteristics of the organic emissions from wood products dryers

described above, the dryer exhaust gas contains a substantial amount of organic material that is

condensible in the range of 50° to 120° C (120° to 250°F). Because all of the test methods described

earlier contain a filter to collect PM, the amount of this material that remains on that filter and the

amount that will be measured downstream from the filter depend on the operating temperature of the

filter. Consequently, the material classified as PM-10, condensible PM, and VOC differs, depending on

filter temperature. The situation related to VOC emissions is further complicated by the presence of

aldehydes and ketones in the exhaust streams from dryers and presses. The paragraphs below first

address the PM-10 issues and then the VOC issues.

The applicability sections for M201 and M201A indicate that if PM-10 results are to be used for

purposes such as inventories, then the PM-10 results from those methods should be added to condensible

PM results from M202 to obtain total PM-10 emissions. Because the primary purpose of AP-42 is to aid

in preparing emission inventories, such a combination appears to be appropriate for developing AP-42

emission factors. However, condensible PM emissions can be determined via M202 in conjunction with

a variety of trains. The available data base on condensible PM emissions from the wood products

industry has been obtained using a M202 train following M5 and M201A trains. Because these trains

operate at different filter temperatures, they can generate different measures of condensible PM

emissions for the same facility. Furthermore, because M201A operates with an in-stack filter, the

distribution of filterable and condensible fractions will vary from site to site depending on stack gas

temperatures. In addition, measurements of filterable PM by M5 and PM-10 by M201 or M201A on the

same stack gas can result in a PM-10 emission rate that is higher than the filterable PM emission rate

because of the differences in sampling train filter temperatures. Such differences complicate averaging

results across facilities to develop emission factors.
3.0 Pollutants and Emission Measurement Methods

3-9

3.3.4 Interrelationship of PM/PM-10 and VOC Emissions

Due to source characteristics, there is an interrelationship between PM/PM-10 and VOC

emissions. Because of this interrelationship, the differences in the test methods described above can

result in measuring some fraction of the organic constituents in the exhaust stream as both PM-10 and

VOC emissions. 

Available test data for wood products dryer emissions indicate that irrespective of filter

temperature, essentially all of the condensible PM that passes through the filter and is collected in the

back half of a PM or PM-10 train is organic material. Also, any organic material that passes through an

in-stack filter used with M25A will be measured as VOC. At the same time, organic material that

condenses between the stack temperature and 120°C (250°F) will be measured as PM-10 by M201 and

M201A. Furthermore, material that condenses in the back half of a M5 train will be classified as

condensible PM by M202. An overlap in the measured PM-10 and VOC emissions in the historical data

base may have occurred. If the recommendations of M201 and M201A related to including condensible

PM in estimating total PM-10 emissions are followed, condensible PM will be measured as both VOC

and PM-10.

3.3.5 Summary of Emission Testing Issues

In summary, plywood and composite wood products industry source characteristics and

differences in test methods used for collecting the historical test data make it difficult to combine the

available data to obtain average emission factors. Consequently, engineering judgment was used to

combine the data and develop average emission factors.

Several general conclusions can be made regarding the measurement of PM-10 and VOC

emissions for these sources. First, the source characteristics result in an interrelationship between

PM/PM-10 and VOC. The constituent organic pollutants emitted act as both PM and VOC. When an instack filter is used during sampling, the measured filterable PM, condensible PM, and VOC will be

affected by the stack gas temperature. Consequently, these measurements should be made under normal

operating conditions; ideally, simultaneous measurements should be taken.

Second, the PM-10 and VOC test methods should be conducted to minimize the amount of

overlap in their measurement. Use of M201 or M201A for filterable PM-10 in conjunction with M202

for condensible PM-10 will provide total PM-10 results on the same basis (distribution of emissions

between the filterable and condensible fraction will be dependent upon stack gas temperature because the

M201 and M201A trains use an in-stack filter). Use of M25A with an in-stack filter will provide VOC

data on the same basis as the PM-10 measurements. In this case, the condensible organic PM-10 fraction

measured using M202 will also be measured as VOC by M25A. However, the amount of measurement

overlap can be estimated.

Finally, M25A has a very low response to formaldehyde, and a reduced response to other

aldehydes and ketones; consequently, the VOC emissions measured by M25A will be biased low in cases

where these compounds are present. A separate measurement method (e.g., NCASI’s impinger method

or M0011) should be used to quantify these compounds when they are expected to be present in the

emissions; for example, in the exhaust gases from the presses and from drying operations.
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4.0 Review of Emission Data

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4.0 Review of Emission Data

As part of the analysis of the emission data, the quantity and quality of the information contained

in the reference documents were evaluated. The following data were excluded from consideration:

# Test series averages reported in units that cannot be converted to the selected reporting units;

# Test series representing incompatible test methods (i.e., comparison of EPA Method 5 front

half with EPA Method 5 front and back half);

# Test series of controlled emissions for which the control device is not specified;

# Test series in which the source process is not clearly identified and described; and

# Test series in which it is not clear whether the emissions were measured before or after the

control device.

Test data sets that were not excluded were assigned a quality rating. Data used for AP-42 are

assigned A through D letter ratings, where A represents the most reliable data. The rating system used

was that specified by EFIG for preparing AP-42 sections. The data were rated as follows:

A Multiple test runs that were performed using sound methodology and reported in enough

detail for adequate validation. These tests do not necessarily conform to the methodology

specified in EPA reference test methods, although these methods were used as a guide for the

methodology actually used.

B Tests that were performed by a generally sound methodology, but lack enough detail for

adequate validation.

C Tests that were based on an unproven or new methodology, or that lacked a significant

amount of background information.

D Tests that were based on a generally unacceptable method, but may provide an

order-of-magnitude value for the source.

The following criteria were used to evaluate test reports and other primary sources of emission

data for sound methodology and adequate detail:

1. Source operation. The manner in which the source was operated is well documented in the

report. The source was operating within typical parameters during the test.

2. Sampling procedures. The sampling procedures conformed to a generally acceptable

methodology. If actual procedures deviated from accepted methods, the deviations are well documented. 

When this occurred, an evaluation was made of the extent to which such alternative procedures could

influence the test results.
4.0 Review of Emission Data

4-2

3. Sampling and process data. Adequate sampling and process data are documented in the

report, and any variations in the sampling and process operation are noted. If a large spread between test

results cannot be explained by information contained in the test report, the data are suspect and are given

a lower rating.

4. Analysis and calculations. The test reports contain original raw data sheets. The

nomenclature and equations used were compared to those (if any) specified by EPA to establish

equivalency. The depth of review of the calculations was dictated by the reviewer’s confidence in the

ability and conscientiousness of the tester, which in turn was based on factors such as consistency of

results and completeness of other areas of the test report.

4.1 AP-42

For this study, average emission factors were not taken from the four previous AP-42 sections

(plywood, OSB, MDF, and particleboard). Rather, the emission and process data from the individual

tests were retrieved from the background reports to allow averaging with the new data (from the 99 new

emission test reports and NCASI). The data from the previous AP-42 background reports had already

undergone a thorough EPA review and rating process and were ready to be incorporated with the new

data. The review and rating process for AP-42 is described in detail in the EPA manual, Procedures for

Preparing Emission Factor Documents.

119

Due to the large quantity of data in the previous AP-42 background reports, the additional

emission test reports, and the NCASI database, and the understanding that the additional data would

generally be higher A- and B-rated data, all C- and D-rated data from the previous AP-42 background

reports were discarded. The discarded data include emission factors in incompatible units, data based on

measurements with unspecified test methods, and data where process operations were not clearly defined.

4.2 Emission Test Reports

The review of the 99 new emission test reports consisted primarily of quality assurance and

quality control (QA/QC) review of the emissions calculations, extraction of process information, and

assigning of a quality rating like that done for AP-42. It is important to note that this review did not

include an in-depth look at field and laboratory procedures to evaluate the degree to which prescribed

methods were followed. For purposes of this review, it was assumed that testing contractors and

analytical laboratories followed the procedures of the methods that have been indicated in the test

reports. However, attention was given to discussions of any problems or unusual circumstances

encountered during the testing. The EMC was asked to review a list of the emissions sources and

emissions test methods cited in these reports to ensure that the proper methods were selected. The

approach used to review and extract data from the emission test reports is discussed below, and is also

presented in a separate memorandum.120

The QA/QC review of the additional emission test reports involved retrieving run-specific stack

parameters, pollutant concentrations, and production rates from the emission test reports and entering the

raw data into a series of spreadsheets to recalculate stack gas standard flow rates, mass emission rates of

pollutants in units of pounds per hour (lb/hr), and emission factors in units of pounds of pollutant per

process rate unit (for example, pounds of pollutant per oven-dried ton of wood). Reports that lacked raw

data sheets or other significant supporting data to allow recalculation of mass emission rates (summary

reports) were generally not reviewed and, consequently, were not used for emission factor development. 
4.0 Review of Emission Data

4-3

For test runs with pollutant concentrations below the method detection limit (MDL), a value equal to half

of the MDL was entered and clearly noted in the spreadsheets.

Emissions data for all pollutants (HAP and non-HAP) in the test reports were included in the

review. Data collected with EPA Method 25A were tabulated as THC on a carbon basis. Where THC

concentrations were provided as parts per million by volume (ppmv) as propane, the values were

multiplied by a factor of 3 to obtain ppmv as carbon. No adjustments were made to individual data

points for non-VOC compounds, such as methane, acetone, and methylene chloride. No adjustments

were made to individual data points for compounds with reduced response rates to the flame ionization

detector (FID), such as oxygenated compounds, including formaldehyde. The adjusted VOC emission

factors were calculated from average emission factors, as described above in Section 3.2.1. There are no

EPA Method 25 runs in the test reports submitted.

Particulate matter (PM) emissions data were tabulated as filterable PM, filterable PM-10, or

condensible PM, as appropriate. Recalculation of PM mass emission rates began with raw catch weights

in grams.

All other pollutants were reported on an “as pollutant” basis. Recalculation of mass emission

rates generally began with dry ppmv. Where wet ppmv were provided, these units were first converted to

dry ppmv (the equation for this conversion is presented in Attachment 3). In the case of CO2, the

calculation began with percent CO2 in the exhaust stream.

After the data were entered into the spreadsheets, a QA/QC check was performed on the

spreadsheets. This check included identifying data entry errors, as well as identifying data that appeared

to be out of the typical ranges. During the QA/QC check, individual wood products mills were contacted

to clarify information contained in the test reports and/or to obtain additional information (e.g., process

rates to allow calculation of emission factors). The spreadsheets subsequently were updated to include

any clarifications and new information provided by the mills.

In addition to the stack parameters, process rates, and other data required for the QA/QC review,

additional process information was extracted to aid in analyzing the emissions data. These process

parameters were entered into a second set of columns to the right of the QA/QC columns in the review

spreadsheets. A number of process parameters were tabulated for each source type. Because different

parameters were desired for different source types, and to make data entry and analysis easier, separate

spreadsheets were created for the eight general source types for which emission test reports were

submitted: hot presses; board coolers; rotary dryers; tube dryers; veneer dryers; conveyor dryers;

hardboard/fiberboard kilns, ovens, and dryers; and miscellaneous sources.

In some cases, plant-specific data from responses to the EPA’s 1998 MACT survey of the

plywood and composite wood products industry were used to fill gaps in the process data. However, the

only survey response data used were for process parameters that are relatively constant, such as press

size, dryer type, resin type and dryer firing method. Process data that vary greatly over time (e.g.,

equipment throughput) were not pulled from the survey responses, nor was confidential business

information (CBI) used to fill data gaps.

Data ratings were assigned to the individual emission test data based on EFIG guidance. A

summary of the rating structure is presented previously in this section. Generally, the data from the test

reports were assigned A ratings if they were based on 3 or more emission test runs. If the test included
4.0 Review of Emission Data

4-4

only 2 runs, the data were rated B. If the test included only 1 run, the data were further downrated to C. 

The emission data were also downrated if the test report noted any conditions that may have adversely

impacted the validity of the test data.

4.3 NCASI Data

The NCASI provided EPA with an electronic data base of the run-by-run emission test data

summarized in technical bulletins 768 through 774. The run-by-run data in the data base were in units of

concentration (ppm) and mass rate (lb/hr and lb/unit operation throughput). The method detection limit

(MDL) was included in the data base for test runs that were non-detect (i.e., below the MDL, or “BDL”). 

These run-by-run data were extracted from the NCASI data base.

Due to the extensive data review process within NCASI, review of the NCASI data was less

stringent than that for the emission test reports submitted with survey responses. Pollutant

concentrations and mass emission rates were not recalculated as for the 99 emission test reports. Review

of the NCASI data essentially consisted of recalculating average emission factors from the individual run

data for each emission source and assigning a data rating. However, attention was also given to

discussions in the technical bulletins of any difficulties or unusual circumstances encountered during the

test program.

Generally, the NCASI data were assigned A ratings if they were based on 3 or more emission test

runs. If the test included only 2 runs, the data were rated B. If the test included only 1 run, the data were

further downrated to C. The emission data were also downrated if any conditions were noted which may

have adversely impacted the validity of the test data.

The most significant adjustment made to the NCASI data was the recalculation of emission

factors incorporating “non-detect” test runs. In general, when calculating emission factors, NCASI

treated non-detects as “zero.” While there are no set rules for handling non-detect data, the methodology

used by EPA when developing emission factors for AP-42 is to assign a value of one-half of the MDL for

non-detect runs. This same methodology was applied for the data from the emission test reports. Thus,

for consistency with the data extracted from the previous AP-42 background reports and the emission test

reports, non-detect runs were reassigned a value of one-half the MDL when recalculating the average

NCASI emission factors. A detailed discussion of the treatment of non-detect data by NCASI and by

EPA is presented in a separate memorandum.121

Once the run-by-run data were extracted from the NCASI data base and averaged, the averages

(where no non-detect runs were involved) were compared with the values calculated by NCASI, as

reported in the technical bulletins. Only those emission factors not including BDL data could be

compared in this manner. For sources with multiple vents, emissions from the vents must be summed in

order to determine total emissions from the source. The approach to summing emissions for sources with

multiple vents was compared with the approach taken by NCASI, using the technical bulletins as a guide. 

Process data for each unit operation was provided in the technical bulletins.
5.0 Emission Factor Calculations

5-1

5.0 Emission Factor Calculations

5.1 General Approach

First, emission test data (typically averages of three-run tests) from the previous AP-42

background reports, the MACT survey test reports, and the NCASI database were combined in a

spreadsheet. Next, the test data were grouped by product, pollutant, source type, and APCD. Other

parameters that could significantly impact emissions also were used to group the data when appropriate. 

Once grouped, the test data were used to calculate average emission factors.

5.2 Grouping of Emission Data

The emission data were sorted into several groups. Grouping by pollutant, wood product, and

general source type (e.g., tube dryer, veneer dryer) was straightforward. However, some interpretation of

the data was necessary for deciding how to group the data by APCD and how to further group the

emission data within source types (e.g., segregate plywood veneer dryer data by firing method).

5.2.1 Grouping by Air Pollution Control Device

Primary cyclones installed for product recovery are not considered APCDs. Instead, they are

considered to be process equipment because they are a necessary part of the production process; without

them, the primary raw material would be lost and the manufacturing process could not continue. 

Emissions test data collected at the outlet of primary cyclones are considered to be uncontrolled for all

pollutants including filterable PM, condensible PM, and PM-10.

Based on a review of the control efficiency data, APCDs installed for PM abatement were

considered to have no effect on gaseous emissions, such as THC, CO, CO2, NOx, and gaseous HAP. 

These APCDs include cyclones, multiclones, baghouses, and EFBs. As a result, emission test data for

sources with PM controls were averaged with the uncontrolled emission test data for all pollutants except

filterable PM, condensible PM, and PM-10.

Wet electrostatic precipitators and wet scrubbers installed for PM control also were considered

to have no effect on gaseous emissions. These wet systems may achieve short-term reductions in THC or

gaseous HAP emissions. However, the HAP and THC control efficiency data, which range from slightly

positive to negative values, indicate that the ability of these wet systems to absorb water-soluble

compounds (such as formaldehyde) diminishes as the recirculating scrubbing liquid becomes saturated

with these compounds. Thus, as for the other PM controls, test data for WESPs and wet scrubbers were

averaged with uncontrolled test data for all pollutants except filterable PM, condensible PM, and PM-10.

One wet scrubbing system, a combination water tray tower/high energy venturi scrubber that uses

treated water and is designed to minimize emissions of both PM and odorous compounds from a

hardboard press, did achieve notable HAP and THC emissions reductions. This system reduced

formaldehyde and methanol emissions by 65 percent and 50 percent, respectively, and reduced THC

emissions by 86 percent.113 Separate emission factors were developed for the outlet of this scrubber.
5.0 Emission Factor Calculations

5-2

Data were available for several control technologies that achieve significant THC and HAP

removal. Most of these technologies are incineration-based, including thermal oxidizers, RTOs, RCOs,

and exhaust gas recirculation systems. Data were also available for biofiltration systems. Separate

emission factors were developed for sources with outlet data for each of these control devices.

5.2.2 Grouping Within Source Types

There are several operating and design parameters which may affect emissions from dryers,

presses, and other wood products emission sources. For example, dryer emissions may be affected by

wood furnish characteristics (e.g., wood species, age, season), heat source, fuel, temperature, percent

fines, resin addition, etc. Press emissions may be affected by type and amount of resin applied, wood

species, moisture content, cycle time, temperature, addition of catalysts and scavengers, etc. Lists of the

parameters EPA attempted to collect for each emission source type are included in the memorandum

describing the emission test report review process.120 It is not practical to consider all of these

parameters for emission factor development because the data set becomes smaller each time a distinction

is made. Also, in many cases, the source-to-source variability was greater than the variability associated

with operating parameters.

Some parameters affect emissions more than others. Furthermore, a parameter that increases

emissions of one pollutant may simultaneously decrease emissions of another pollutant. Therefore, care

was taken to select the parameters that may have the most significant effect on HAP emissions when

deciding how to further group emission data within emission source types. Discussions of grouping

according to source parameters in the NCASI technical bulletins were reviewed in making decisions on

how to group the emission data. In addition, the grouping schemes used in the previous edition of AP-42

were also considered because these schemes were reviewed by industry representatives when the AP-42

sections were developed.

Dryers within each industry sector were generally differentiated by firing type, fuel type, and

wood species. For MDF and hardboard tube dryers, further distinctions were made for blowline versus

non-blowline blending, resin type, and for secondary (relay) dryers. For hardboard and fiberboard board

dryers, distinctions were made for differing binder systems. Hot presses within each industry sector were

differentiated by resin type only. For the remaining sources, distinctions were made as warranted by the

data. 

For particleboard and MDF rotary dryers, a distinction was made between predryers or “green”

dryers and “dry” dryers, based on furnish moisture content. Wood moisture content can be expressed on

an oven-dry (or dry) basis or on a wet basis. In the plywood and composite wood products industry,

percent moisture content is commonly expressed as percent moisture content on a dry basis. The drybasis moisture content is determined by weighing a sample of wood before and after oven-drying and

then calculating the moisture content based on the weight before and after drying. Moisture content on a

dry basis is calculated by the following equation:

% Moisture Content (dry basis) =

weight of water in wood

× 100

weight of oven-dry wood

Alternately, wood moisture content may be expressed on a wet basis. The procedure for determining

wet-basis moisture content involves the same weighing and drying of a wood sample as for the dry-basis
5.0 Emission Factor Calculations

5-3

determination; however, the calculation of the wet-basis value uses the wet weight of the wood, instead

of the dry weight of the wood, as the denominator. Moisture content on a wet basis is calculated by the

following equation:

% Moisture Content (wet basis) =

weight of water in wood

× 100

weight of wet wood

In general, dryers that dried furnish with a moisture content of greater than 50 percent (dry basis) were

considered green dryers. Dryers that dried furnish with a moisture content less than 50 percent (dry

basis) were considered dry dryers. There were a few instances in which dryers that were used to dry

furnish with a reported moisture content just below the 50 percent threshold were included with the green

dryers because the plant considered them to be green dryers or predryers.

In cases where one species (or group of species, e.g., softwoods) accounted for 70 percent or

more of the wood mix processed by a given process unit, the process unit was categorized by that

species. For example, if a dryer processed 70 percent pines and 30 percent mixed hardwoods, the dryer

was grouped with softwood dryers. If the dryer processed 40 percent softwood and 60 percent hardwood,

the dryer was grouped with mixed wood species dryers.

Where emission factors for mixed hardwood and softwood species have been calculated, the

wood species mix has been specified. Emission factors for other mixes of hardwood and softwood

species may be calculated by combining the emission factors for hardwoods and softwoods in the ratio

specific to a given application. For example, an uncontrolled THC emission factor for a direct woodfired OSB rotary dryer processing 70 percent softwood and 30 percent hardwood may be calculated using

the uncontrolled THC emission factor for softwood (6.7 lb/ODT) and hardwood (1.7 lb/ODT), and the

ratio of 70 percent to 30 percent. The resultant emission factor, rounded to two significant figures,

would be 5.2 lb/ODT.

5.3 Calculating Emission Factors

Once the emission data were grouped according to pollutant, APCD, and source type, they were

then averaged to develop average emission factors. The data available for some of the emission factors

developed included the results of multiple tests on the same piece of equipment. In such cases, the testspecific emission factors for the same piece of equipment were averaged first, and that average emission

factor then was averaged with the factors for the other pieces of equipment to yield the overall average

emission factor. The averaging of multiple tests on the same piece of equipment was more often an issue

for criteria pollutants; it occurred much less frequently for HAP compounds.

The number of non-detect test runs for each emission data point were considered before they

were subsequently averaged into emission factors. If all of the test data for a source were based on nondetect test runs, then no emission factor was developed and a “BDL” code was substituted for the

numeric emission factor. If some of the data were non-detect and some were above the MDL, then

values of one-half of the MDL were averaged into the emission factors for the non-detect test runs.

Some tests have higher MDLs than others in the same data set. This can lead to situations where

using half of a high MDL will bias the average high. If the half-MDL value for a non-detect test is higher

than all detect values for the other tests in the data set, the non-detect test is discarded. If the half-MDL
5.0 Emission Factor Calculations

5-4

values are less than detect values, they are included in the average. Attachment 2 is a table with an

example calculation to illustrate how the average emission factors were calculated from the individual

data points.

5.4 Emission Factor Ratings

The quality of the emission factors developed from analysis of the test data was rated using the

following general criteria:

A – Excellent: Developed from A- and B-rated source test data taken from many randomly

chosen facilities in the industry population. The source category is specific enough so that variability

within the source category population may be minimized.

B – Above average: Developed only from A- or B-rated test data from a reasonable number of

facilities. Although no specific bias is evident, it is not clear if the facilities tested represent a random

sample of the industries. The source category is specific enough so that variability within the source

category population may be minimized.

C – Average: Developed only from A-, B- and/or C-rated test data from a reasonable number of

facilities. Although no specific bias is evident, it is not clear if the facilities tested represent a random

sample of the industry. In addition, the source category is specific enough so that variability within the

source category population may be minimized.

D – Below average: The emission factor was developed only from A-, B-, and/or C-rated test

data from a small number of facilities, and there is reason to suspect that these facilities do not represent

a random sample of the industry. There also may be evidence of variability within the source category

population. Limitations on the use of the emission factor are noted in the emission factor table.

E – Poor: The emission factor was developed from C- and D-rated test data, and there is reason

to suspect that the facilities tested do not represent a random sample of the industry. There also may be

evidence of variability within the source category population. Limitations on the use of these factors are

footnoted.

U – Unrated: For two of the revised AP-42 sections (plywood and OSB) some of the emission

factors are based on one test conducted at one facility with either a source/control device configuration,

or process operating parameters that are specific to that facility and may not be representative of any

other facilities; those emission factors are unrated and are indicated with an emission factor rating of U.

The use of these criteria is somewhat subjective and depends to an extent upon the individual

reviewer.

The ratings assigned to the average emission factors are largely a function of the data ratings

assigned to the individual data sets and the number of data sets upon which the average emission factors

are based. Generally, C- and D-rated data were discarded and were not used in the determination of

average emission factors. However, C-rated data were used if the data were downrated only because they

were 1-run data. Average emission factors based on a single data set were rated E. For factors based on

multiple data sets, the ratings were based primarily on the number of data sets. In general, the average

emission factors were rated D, if based on less than 10 data sets, emission factors based on 10 to 19 data
5.0 Emission Factor Calculations

5-5

sets were rated C, and factors based on 20 or more data sets were rated B. No emission factors were

assigned an A rating.

The VOC-as-propane emission factors were assigned ratings one rating below the corresponding

THC-as-carbon emission factor rating (unless both were rated E). Emission factors based solely on

M0011 data for compounds other than formaldehyde, acetaldehyde, and propionaldehyde were

downrated (unless they were already rated E) because M0011 has not been validated for these other

compounds and the results are likely to be biased low.
5.0 Emission Factor Calculations

5-6

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6.0 References

6-1

6.0 References

1. Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources,

U.S. Environmental Protection Agency, Research Triangle Park, NC, 1995.

2. Emission Factor Documentation for AP-42 Section 10.5, Plywood Manufacturing, U. S.

Environmental Protection Agency, Research Triangle Park, NC, September 1997.

3. Emission Factor Documentation for AP-42 Section 10.6.1, Waferboard/Oriented Strandboard

Manufacturing, prepared for the U. S. Environmental Protection Agency, OAQPS/EFIG, by

Midwest Research Institute, Cary, NC, December 1998.

4. Emission Factor Documentation for AP-42 Section 10.6.2, Particleboard Manufacturing,

prepared for the U. S. Environmental Protection Agency, OAQPS/EFIG, by Midwest Research

Institute, Cary, NC, September 1998.

5. Emission Factor Documentation for AP-42 Section 10.6.3, Medium Density Fiberboard

Manufacturing, prepared for the U. S. Environmental Protection Agency, OAQPS/EFIG, by

Midwest Research Institute, Cary, NC, September 1998.

6. A Study of Organic Compound Emissions from Veneer Dryers and Means for Their Control,

Technical Bulletin No. 405, National Council of the Paper Industry for Air and Stream

Improvement, Inc., New York, NY, August 1983.

7. Oriented Strandboard and Plywood Air Emission Databases, Technical Bulletin No. 694,

National Council of the Paper Industry for Air and Stream Improvement, Inc., New York, NY,

April 1995.

8. Particleboard and Medium Density Fiberboard Air Emission Databases, Technical Bulletin No.

693, National Council of the Paper Industry for Air and Stream Improvement, Inc., New York,

NY, April 1995.

9. Results of a Series of Source Emission Tests on the OSB Core Wafer Dryer Exhaust and the

Board Press Hood Exhaust at Northwood Panelboard Co., Solway, Minnesota, October 9-10,

1997, prepared for Northwood Panelboard Company, by MMT Environmental Services, Inc.,

MMT Report No. 10257, November 18, 1997.

10. Results of a Series of Source Emission Compliance Tests (TSP, PM10, VOC, CO, NOx,

Formaldehyde and Opacity) on the OSB Wafer Dryer at Northwood Panelboard Co., Solway,

Minnesota, February 28 - March 2, 1997, prepared for Northwood Panelboard Company, by

MMT Environmental Services, Inc., MMT Report No. 10235, March 21, 1997.
6.0 References

6-2

11. Volatile Organic Compound Destruction Efficiency Testing of the Regenerative Catalytic

Oxidizer at the ABTCo. Facility in Alpena, Michigan, Test Dates November 24-25, 1998,

prepared for Durr Environmental, Inc., by Clayton Environmental Consultants, Inc., Clayton

Project No. 13-99342.00, December 14, 1998.

12. Emission Studies on Boiler No. 1, 2 and 3 Located at the ABTCo Facility Alpena, Michigan, Test

Dates December 9-11, 1998, prepared for ABTCo, Inc., by NTH Consultants, Ltd., February 1,

1999.

13. Source Emission Test Report, Dryer and Press Exhausts, Allegheny MDF Limited Partnership,

Mt. Jewett, Pennsylvania, Test Dates October 22-24 and December 17, 1997, prepared for

Allegheny MDF Limited Partnership, by Galson Measurements, Galson Project No. 975540,

December 3, 1997.

14. Emissions Test Report, Boise Cascade Corporation, Island City, Oregon, Green Furnish Dryer,

March 10 & 11, 1998, prepared for Boise Cascade Corporation, by BWR Associates, Inc.,

Project No. 98-042D, 1998.

15. Title V Emissions Test Report, PM10, Particulate Matter, Condensible Particulate Matter,

Aldehydes/Ketones, Phenols, Methanol, Oxygen, Carbon Dioxide, Carbon Monoxide, Nitrogen

Oxides, and Cold Total Hydrocarbons from Process Stacks, Georgia Pacific Hardboard

Manufacturing Plant, North Little Rock, Arkansas, Test Dates September 26-29, 1995, prepared

for CH2M Hill and Georgia Pacific Corporation, by DEECO, Inc., Report No. 95-1200-A,

October 27, 1995.

16. Engineering Emissions Testing Performed on the Core Dryer and Face Dryer Cyclone Exhaust

Stacks, Georgia Pacific, Vienna, Georgia, Test Dates: March 1-2, 1995, prepared for Georgia

Pacific Corporation, by Air Techniques, Inc., ATI Job No. 95T03991, 1995.

17. Title V Emissions Testing on the Furnish Dryer Exhaust, Georgia Pacific Corporation,

Panelboard Plant, Monticello, Georgia, February 13, 1996, prepared for CH2M Hill, by

Analytical Testing Consultants, Inc., Report No. 5743, March 13, 1996.

18. Emission Test Results for Formaldehyde from the Primary and Secondary Stacks of Dryer 1 and

Dryer 2, Georgia Pacific Fiber Board Plant, Holly Hill, South Carolina, Test Dates May 31 to

June 1, 1995, prepared for Georgia Pacific Corporation, by DEECO, Inc., Report No. 062895-

1235, June 28, 1995.

19. Results of the January 17-19, 1995 Source Emission Tests on the Dryer Stack, Dump Stack and

Humidification Kiln Stack at the Georgia Pacific Facility Located in Phillips, Wisconsin,

prepared for CH2M Hill, by PACE, Inc., Project No. 941228.401, March 2, 1995.

20. Summary of Test Results, May 11, 1995 Testing, Georgia Pacific, Phillips, Wisconsin, prepared

for CH2M Hill, by PACE, Inc., Project No. 941228.401, May 18, 1995.

21. Results of the September 27-29, 1995 Emission Tests on the Fluidized Bed Boiler Dump Stack

and Flash Tube Dryer Stack at the Georgia Pacific Facility Located in Phillips, Wisconsin,
6.0 References

6-3

prepared for Georgia Pacific Corporation, by PACE, Inc., Project No. 950828.401, November 7,

1995.

22. Summary of Test Results, March 23-24, 1995 Testing, Georgia Pacific, Phillips, Wisconsin,

prepared for CH2M Hill and Georgia Pacific Corporation, by PACE, Inc., April 12, 1995.

23. Stationary Source Sampling Report for Georgia Pacific Corporation, Mt. Hope, West Virginia,

Wellons Energy Unit, Press Vent, Test Dates August 7-8, 1996, prepared for Georgia Pacific

Corporation, by Trigon Engineering Consultants, Inc., Project No. 047-96-004, August 1996.

24. Compliance VOC and Formaldehyde Emissions Testing Performed on the Press Vent RTO

System at Masonite Corporation, Cordele, Georgia, Test Date February 23, 1995, prepared for

Masonite Corporation, by Air Techniques, Inc., ATI Job No. 94T03968, 1995.

25. Engineering VOC and Formaldehyde Emissions Testing Performed on the Press Vent RTO

System Inlet at Masonite Corporation, Cordele, Georgia, Test Date March 31, 1995, prepared

for Masonite Corporation, by Air Techniques, Inc., ATI Job No. 95T04069, 1995.

26. Formaldehdye and VOC Emissions Testing Performed at Masonite Corporation, Cordele,

Georgia, Test Date April 18, 1996, prepared for Masonite Corporation, by Air Techniques, Inc.,

ATI Job No. 96T04537, 1996.

27. Formaldehdye and VOC Emissions Testing Performed at Masonite Corporation, Cordele,

Georgia, Test Date May 9, 1996, prepared for Masonite Corporation, by Air Techniques, Inc.,

ATI Job No. 96T04585, 1996.

28. Formaldehdye and VOC Emissions Testing Performed at Masonite Corporation, Cordele,

Georgia, Test Date June 5, 1996, prepared for Masonite Corporation, by Air Techniques, Inc.,

ATI Job No. 96T04609, 1996.

29. WESP Emission Test Report, Masonite Corporation, Cordele, Georgia, Test Date September 11,

1997, prepared for Masonite Corporation, by Roy F. Weston, Inc., Work Order No. 10414-004-

001, October 7, 1997.

30. Report of Particulate/VOC and Formaldehyde Emissions Tests for Masonite Corporation, Lines

I and II Press Vents, Laurel, Mississippi, Test Dates March 10-11, 1998, prepared for Masonite

Corporation, by Environmental Monitoring Laboratories, March 27, 1998.

31. Stationary Source Sampling Report, Reference No. 14337, International Paper, Stuart, Virginia,

Emissions Testing for Carbon Monoxide, Formaldehyde, Nitrogen Oxides, Particulate, Total

Hydrocarbons, Dryer No. 1 Stacks A and B, Boiler, Test Dates June 13-15, 1995, prepared for

International Paper, by Entropy, Inc., June 1995.

32. Emission Test Report Particleboard Press and No. 2 Rotary Dryer (MEC Dryer with WoodFired Burner) Emissions Testing, International Paper, Decorative Products Division, Stuart,

Virginia, Test Dates June 8-10, 1998, prepared for International Paper Decorative Products

Division, by Roy F. Weston, Inc., Work Order No. 00157-045-002, June 1998.
6.0 References

6-4

33. Report of Air Emissions Tests for Louisiana-Pacific Corporation Clayton MDF Plant, Test Dates

August 22-23, 1995, prepared for Louisiana-Pacific Corporation, by Environmental Monitoring

Laboratories, Inc., September 13, 1995.

34. Report of Particulate/CO/VE/NOx/VOC Emissions Tests for Louisiana-Pacific Corporation

Clayton MDF Plant Nos. 1 and 2 Wood Waste Boilers, Test Dates June 26-27, 1997, prepared

for Louisiana-Pacific Corporation, by Environmental Monitoring Laboratories, Inc., July 18,

1997.

35. Source Test Report: Preliminary Compliance Test of a Regenerative Thermal Oxidizer at

Louisiana-Pacific Corporation Oroville, California, Test Dates November 12-13, 1996, prepared

for Louisiana-Pacific Corporation, by Normandeau Associates, Inc., Project No. 16802.000,

1996.

36. Butte County Air Quality Management District Compliance Source Test Report for LouisianaPacific Corporation Merlo Avenue Facility (Oroville), Regenerative Thermal Oxidizer, Test

Dates May 5-7, 1998, prepared for Louisiana-Pacific Corporation, by Aeros Environmental, Inc.,

Project No. 217-1190, June 16, 1998.

37. Butte County Air Quality Management District Compliance Source Test Report for LouisianaPacific Corporation Merlo Avenue Facility (Oroville), Regenerative Thermal Oxidizer, Test

Dates July 29-31, 1997, prepared for Louisiana-Pacific Corporation, by Aeros Environmental,

Inc., Project No. 217-928, September 10, 1997.

38. Source Test Report: Emissions Compliance Test of a Regenerative Thermal Oxidizer at

Louisiana-Pacific Corporation Oroville, California, Test Dates December 18-19, 1996, prepared

for Louisiana-Pacific Corporation, by Normandeau Associates, Inc., Project No. 16802.002,

1996.

39. Source Test Report: Source Testing of Various Process Emissions at Louisiana-Pacific

Corporation Oroville, California, Test Dates July 31 - August 4, 1995, prepared for LouisianaPacific Corporation, by Normandeau Associates, Inc., Project No. 15747.000, September 7,

1995.

40. Source Test Report: Particulate Matter Emissions from Line 1 Filter Box at Louisiana-Pacific

Corporation Oroville, California, Test Date August 16, 1996, prepared for Louisiana-Pacific

Corporation, by Normandeau Associates, Inc., Project No. 16605.000, 1996.

41. Results of the November 14-17, 1995 Air Emission Compliance Tests at the Louisiana-Pacific

Waferboard Plant in Missoula, Montana, prepared for Louisiana-Pacific Corporation, by

Interpoll Laboratories, Inc., Report No. 5-6833, December 27, 1995.

42. Report of Air Emissions Tests for Louisiana-Pacific Corporation Silsbee Particleboard Facility

Press Vent Baghouse, Test Date September 25, 1997, prepared for Louisiana-Pacific

Corporation, by Environmental Monitoring Laboratories, Inc., October 17, 1997.
6.0 References

6-5

43. Report of Air Emissions Tests for Louisiana-Pacific Corporation Silsbee Particleboard Facility

Core and Face Dryer Cyclones, Test Date September 23, 1997, prepared for Louisiana-Pacific

Corporation, by Environmental Monitoring Laboratories, Inc., October 18, 1997.

44. Report of Formaldehyde/CO/NOx Emissions Tests for Louisiana-Pacific Corporation Silsbee

Particleboard Facility Core and Face Dryer Cyclones, Test Date September 23, 1997, prepared

for Louisiana-Pacific Corporation, by Environmental Monitoring Laboratories, Inc., October 18,

1997.

45. Emission Test Report, MDI Emission Testing, Batch Press Vent, Louisiana-Pacific, Tomahawk,

Wisconsin, Test Dates August 25-26, 1997, prepared for ICI Polyurethanes Group, by Roy F.

Weston, Inc., Work Order No. 11251-004-001, November 10, 1997.

46. Report for PM-10 Emission Measurements from the Press Vents, SierraPine, Ltd., Rocklin,

California, Test Dates May 17-19, 1995, prepared for SierraPine, Ltd., by Carnot,

December 1995.

47. Report for 1995 VOC Emission Compliance Tests at the Press Vents, SierraPine, Ltd., Rocklin,

California, Test Date August 21, 1995, prepared for SierraPine, Ltd., by Carnot, August 1995.

48. Report for 1995 VOC Emission Compliance Tests at the Wood Fiber Dryers and Press Vents,

SierraPine, Ltd., Rocklin, California, Test Dates April 10-13, 1995 and May 17-19, 1995,

prepared for SierraPine, Ltd., by Carnot, May 1995.

49. Final Report for 1998 Emission Compliance Tests SierraPine, Ltd., Rocklin, California, Test

Dates August 12-20, 1998, prepared for SierraPine, Ltd., by The Avogadro Group, October 27,

1998.

50. Report for PM-10 Emission Measurements from the Wood Fiber Dryers, SierraPine, Ltd.,

Rocklin, California, Test Dates April 10-13, 1995, prepared for SierraPine, Ltd., by Carnot,

April 1995.

51. Report for 1996 PM-10 Emission Measurements for Emission Reduction Credits, SierraPine,

Ltd., Rocklin, California, Test Dates November 19-26, 1996, prepared for SierraPine, Ltd., by

Carnot, April 1997.

52. Results of 1996 Emission Testing of the Regenerative Thermal Oxidizer System at SierraPine,

Ltd., Rocklin, California, Test Dates November 19 and 25, 1996, prepared for SierraPine, Ltd.,

by Carnot, December 1996.

53. Engineering Emissions Testing for Particulate Performed on the #1 & 3 Dryer Cyclone Exhausts

and Engineering Emissions Testing for Methanol Performed on the Press Vents at Temple Inland

Corporation, Monroeville, Alabama, Test Dates February 10-14, 1997, prepared for Temple

Inland, by Air Techniques, Inc., ATI Job No. 97TO4908, 1997.

54. In-House Air Emissions Testing of Primary Dryer Outlet, Hope Particleboard Plant, Hope,

Arkansas, Test Dates January 29-31, 1997, prepared for Temple-Inland Forest Products

Corporation, by Maxim Technologies, Inc., Project No. 1411700875A, March 14, 1997.
6.0 References

6-6

55. In-House Air Emissions Testing of Primary Dryer Outlet and RTO Press Vent Inlet, Hope

Particleboard Plant, Hope, Arkansas, Test Dates February 12-14, 1997, prepared for TempleInland Forest Products Corporation, by Maxim Technologies, Inc., Project No.1411700875B,

March 17, 1997.

56. RTO Outlet Emission Test Report, Temple-Inland Forest Products Corporation, Thomson,

Georgia, Test Dates April 21-22, 1998, prepared for Temple-Inland Forest Products Corporation,

by Roy F. Weston, Inc., Work Order No. 06598-010-002, May 11, 1998.

57. Lumber Kiln Emissions Testing, Diboll and Buna, Texas, Test Dates January 20-23, 1998

(Diboll) and January 26-29, 1998 (Buna), prepared for Temple-Inland Forest Products

Corporation, by Roy F. Weston, Inc., Work Order No. 06598-011-001, April 1, 1998.

58. In-House Air Emissions Testing of the Diboll Particleboard Plant, Diboll, Texas, Test Dates

October 8-9 and 15, 1997, prepared for Temple-Inland Forest Products Corporation, by Maxim

Technologies, Inc., Project No. 9711254A, January 12, 1998.

59. Volatile Organic Compound Sampling and Analysis of Adel’s Full Scale Biofilter, Test Dates

February 1, 1996 to May 14, 1996, prepared for Weyerhaeuser, by Weyerhaeuser, Project No.

721-9569, June 1996.

60. Volatile Organic Compound and Formaldehyde Sampling of Adel’s Biofilter, Test Dates June 18,

1996 to December 23, 1996, prepared for Weyerhaeuser, by Weyerhaeuser, Project No. 721-

3086.

61. Weyerhaeuser Company–Adel, Georgia Particleboard Press Vent VOC and HAP Testing, Test

Dates March 6-18, 1995, prepared for Weyerhaeuser, by Weyerhaeuser, Project No. 721-9520,

September 1995.

62. Source Test Report, Weyerhaeuser Corporation, Adel, Georgia Biofilter Inlet/Outlet Particulate,

Test Date September 10, 1996, prepared for Weyerhaeuser, by Technical Services, Inc., 

September 1996.

63. Source Test Report, Biofilter VOC Emissions Reduction, Weyerhaeuser Corporation, Adel,

Georgia, Test Date September 10, 1996, prepared for Weyerhaeuser, by Technical Services, Inc.,

September 1996.

64. Source Test Report, Weyerhaeuser Corporation, Adel, Georgia, Biofilter Inlet/Outlet

Formaldehyde, Test Date September 11, 1996, prepared for Weyerhaeuser, by Technical

Services, Inc., September 1996.

65. Test Report Determination of Formaldehyde, Methanol, Particulate and Carbon Monoxide

Emissions, Press Biofilter, Weyerhaeuser Structurwood, Grayling, Michigan, Test Dates

December 11-12, 1996, prepared for Weyerhaeuser Structurwood, by Earth Tech, Inc.,

January 1997.
6.0 References

6-7

66. Stationary Source Sampling Report Reference No. 0301, Weyerhaeuser Company, Moncure,

North Carolina, Dry ESP Inlet and Stack, Test Dates March 17-18, 1997, prepared for

Weyerhaeuser Company, by Environmental Technical Group, Inc., April 16, 1997.

67. Stationary Source Sampling Report Reference No. 0097, Weyerhaeuser Company, Moncure,

North Carolina, Wood Boiler Multiclone Inlet and Outlet, Test Dates July 25-27, 1995, prepared

for Weyerhaeuser Company, by Environmental Technical Group, Inc., September 22, 1995.

68. Formaldehyde Methods Comparison, NCASI Acetylacetone Method vs. EPA Method 0011,

Weyerhaeuser Company, Springfield, Oregon, MEC #3 Rotary Particle Dryer, Test Dates

February 27-28, 1996, prepared for Weyerhaeuser Company, by BWR Associates, Inc., 1996.

69. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Thru Door Core Plant Press Vents, VOC

Compliance Testing 1998.3, Test Dates August 6-7, 1998, prepared for Weyerhaeuser Company,

by Weyerhaeuser Company, Project No. 721-9850, September 15, 1998.

70. Weyerhaeuser Company–Marshfield, Wisconsin, Formaldehyde Emissions Variability Study,

Press Area Common Stack, Test Dates April 1, 1998 to June 30, 1998, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9753, 1998.

71. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Thru Door Core Press Vent Testing

1995.3, Test Dates August 25, 1995, prepared for Weyerhaeuser Company, by Weyerhaeuser

Company, Project No. 721-9547, January 8, 1997.

72. Weyerhaeuser Company–Marshfield, Wisconsin, Door Core Dryer, Particulate Compliance

1996.4, Test Date October 19, 1996, prepared for Weyerhaeuser Company, by Weyerhaeuser

Company, Project No. 721-9640, December 12, 1996.

73. Weyerhaeuser Company–Marshfield, Wisconsin, Steam Muffler Vent, Formaldehyde and VOC

Test Method Study 1998.3, Test Dates August 6-7, 1998, and July 25, 1997, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9850, September 29,

1998.

74. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Thru Door Core Dryer and Press

Testing, Formaldehyde Air Emissions 1996.4, Test Dates October 19 and 21, 1996, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9640, December 30,

1996.

75. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Press Testing, Formaldehyde Air

Emissions 1997.3, Test Date July 25, 1997, prepared for Weyerhaeuser Company, by

Weyerhaeuser Company, Project No. 721-9741, 1997.

76. Weyerhaeuser Company–Marshfield, Wisconsin, Door Core Press Scavenger Trials, Press Vent

Formaldehyde Air Emissions 1997.3, Test Dates July 21-24, 1997, prepared for Weyerhaeuser

Company, by Weyerhaeuser Company, Project No. 721-9741, 1997.
6.0 References

6-8

77. Weyerhaeuser Company–Marshfield, Wisconsin, Formaldehyde Emissions Variability Study,

Press Area Common Stack, Test Dates December 18, 1997 to March 26, 1998, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9753, May 26, 1998.

78. Press Room Vent Emissions Sampling, Willamette Industries, Inc., Emerson, Louisiana, Test

Dates February 8-9, 1995, prepared for Willamette Industries, Inc., by Armstrong

Environmental, Inc., Project W-1653-95, February 20, 1995.

79. Engineering Evaluation Test Report, Formaldehyde, Total Hydrocarbons, and Methane

Emissions from Four Process Stacks, Willamette Industries, Inc., Emerson, Louisiana, Test

Dates April 23-24, 1998, prepared for Willamette Industries, Inc., by DEECO, Inc., Project

No. 1559, June 7, 1998.

80. Report of Particulate, VOC, and Formaldehyde Tests for Willamette Industries–Malverne MDF

Facility Line I and Line II Press Vent Baghouses, Malverne, Arkansas, Test Dates May 7-8,

1998, prepared for Willamette Industries, by Environmental Monitoring Laboratories, May 28,

1998.

81. Report of VOC and Formaldehyde Emissions Test for Willamette Industries–Malverne MDF

Facility Line I Press Vent Baghouse, Malverne, Arkansas, Test Date July 24, 1998, prepared for

Willamette Industries, by Environmental Monitoring Laboratories, August 14, 1998.

82. Report of VOC and Formaldehyde Emissions Test for Willamette Industries–Malverne MDF

Facility Line II Press Vent Baghouse, Malverne, Arkansas, Test Date September 10, 1998,

prepared for Willamette Industries, by Environmental Monitoring Laboratories, September 29,

1998.

83. Report of Air Emissions and Inlet Loading Tests for Willamette Industries–Malverne MDF

Facility Line II Dryers Thermal Oxidizer, Malverne, Arkansas, Test Dates March 5-6, 1998,

prepared for Willamette Industries, by Environmental Monitoring Laboratories, April 3, 1998.

84. Report of Air Emissions Tests for Willamette Industries–Arcadia OSB Facility Press Vent

Exhaust, Arcadia, Louisiana, Test Dates October 2-4, 1996, prepared for Willamette Industries,

by Environmental Monitoring Laboratories, November 16, 1996.

85. Report of Air Emissions Tests for Willamette Industries–Arcadia OSB Facility Press Vent

Exhaust, Arcadia, Louisiana, Test Date July 12, 1996, prepared for Willamette Industries, by

Environmental Monitoring Laboratories, July 17, 1996.

86. Report of Air Emissions Tests for Willamette Industries–Arcadia OSB Facility Press Vent

Exhaust, Arcadia, Louisiana, Test Date May 20, 1996, prepared for Willamette Industries, by

Environmental Monitoring Laboratories, August 3, 1996.

87. Report of Air Emissions Tests for Willamette Industries–Arcadia OSB Facility, Arcadia,

Louisiana, Test Dates July 11-12, 1996, prepared for Willamette Industries, by Environmental

Monitoring Laboratories, August 3, 1996.
6.0 References

6-9

88. Emissions Test Report, Willamette Industries MDF, Eugene, Oregon, Primary Dryer and Sander

Dust Baghouse, Test Dates October 3 and 16-18, 1996, prepared for Willamette Industries, by

BWR Associates, Inc., Project No. 96-165X, 1996.

89. Emissions Test Report, Willamette Industries MDF, Eugene, Oregon, Press Vents, Test Dates

November 13-14, 1996, prepared for Willamette Industries, by BWR Associates, Inc., Project

No. 96-165X, 1996.

90. Emissions Test Report, Willamette Industries, Springfield, Oregon, Veneer Dryer #1 and Veneer

Dryer #2, Test Dates June 1-2, 1998, prepared for Willamette Industries, by BWR Associates,

Inc., Project No. 98-092D, 1998.

91. Compliance Test, Formaldehyde and VOC, Board Press Area, Dominance Industries, Inc., Pan

Pacific Products, Broken Bow, Oklahoma, Test Dates September 25-26, 1997, prepared for Pan

Pacific Products, by CETCON, Job No. CJ-1813, October 28, 1997.

92. Compliance Test, Formaldehyde, PM, VOC and CO, Dryer Cyclone 13E, Dominance Industries,

Inc., Pan Pacific Products, Broken Bow, Oklahoma, Test Dates September 22-23, 1997, prepared

for Pan Pacific Products, by CETCON, Job No. CJ-1812, October 23, 1997.

93. Compliance Test, Formaldehyde, PM, VOC and CO, Wood Fired Boiler, Dominance Industries,

Inc., Pan Pacific Products, Broken Bow, Oklahoma, Test Dates September 24-25, 1997, prepared

for Pan Pacific Products, by CETCON, Job No. CJ-1814, October 27, 1997.

94. Emissions Test Report, Willamette Industries Duraflake Division, Albany, Oregon, Dry Dryers 1,

2, 3 and 4, Test Dates May 19-22, 1998, prepared for Willamette Industries, by BWR Associates,

Inc., Project No. 98-044D, 1998.

95. Emissions Test Report, Willamette Industries Duraflake Division, Millersburg (Albany), Oregon,

Green Dryer #3, Test Dates March 27-28, 1997, prepared for Willamette Industries, by BWR

Associates, Inc., Project No. 97-043D, 1997.

96. Emissions Test Report, Willamette Industries Duraflake Division, Albany, Oregon, Boiler #1,

Green Dryer #1, and Green Dryer #2, Test Dates April 22-23 and 25-26, 1996, prepared for

Willamette Industries, by BWR Associates, Inc., Project No. 96-048X, 1996.

97. Potential Volatile Organic Compound (VOC) Emissions from Borden Cascophen® SP-C32K

During Pressing and Press Cool Down (Southern Pine), prepared for Borden, June 13, 1996.

98. Potential Volatile Organic Compound (VOC) Emissions from Borden Cascophen® 7CA31H

During Pressing and Press Cool Down (Douglas Fir), prepared for Borden, June 13, 1996.

99. Potential Volatile Organic Compound (VOC) Emissions from Borden Cascophen® SP-C32K

During Pressing and Press Cool Down (Yellow Poplar), prepared for Borden, June 13, 1996.

100. Emissions Testing for Particulate, Formaldehyde, CO, NOx, VOCs on Various Process Exhausts,

Trus-Joist Macmillan, a Limited Partnership, Buckhannon, West Virginia, Test Dates
6.0 References

6-10

December 12-16, 1995, prepared for Trus-Joist MacMillan, by Analytical Testing Consultants,

Inc., Report No. 5712, January 25, 1996.

101. Information Stack Test Report, Wellons Cyclo-Blast Wood-Fired Furnaces, Wood Strand Dryers,

Fuel Energy Analysis for Trus-Joist MacMillan, Hazard, Kentucky, Test Date March 1, 1996,

prepared for Trus-Joist MacMillan, by Commonwealth Technology, Inc., June 18, 1996.

102. Compliance Stack Test Report, Test Results for Wellons Cyclo-Blast Wood-Fired Furnaces,

Wood Strand Dryers, Siempelkamp Steam Injection Press for Trus-Joist MacMillan, Hazard,

Kentucky, Test Dates February 28-29 and March 27, 1996, prepared for Trus-Joist MacMillan,

by Commonwealth Technology, Inc., June 18, 1996.

103. Volatile Organic Compound (VOC) Emissions from Neste Resins 4001/H1003 Adhesive,

prepared for Boise Cascade Corporation, May 9, 1997.

104. Determination of Carbon Monoxide Emissions from the Thermal Oil Heater Exhaust Stack and

the Strand Dryer Exhaust Stack when Firing Hardwood Species Other than Aspen,

Determination of MDI Emissions from the Press Vent Exhaust Stack, Trus-Joist MacMillan,

Deerwood, Minnesota, Test Dates August 15-16, 1995, prepared for Trus-Joist MacMillan, by

Braun Intertec Corporation, Report No. CMXX-95-0493, September 11, 1995.

105. Determination of Pollutant Emissions from the Strand Dryer System at the Trus-Joist MacMillan

Facility, Deerwood, Minnesota, Test Dates June 8-10, 1998, prepared for Trus-Joist MacMillan,

by Braun Intertec Corporation, Report No. CMXX-98-0389, July 8, 1998.

106. Determination of Carbon Monoxide Emissions from the Thermal Oil Heater and the Strand

Dryer at Trus-Joist MacMillan, Deerwood, Minnesota, Test Date November 18, 1997, prepared

for Trus-Joist MacMillan, by Braun Intertec Corporation, Report No. CMXX-97-0710,

December 22, 1997.

107. Determination of Pollutant Emissions from Six Emission Points at the Trus-Joist MacMillan

Facility, Deerwood, Minnesota, Test Dates November 19-22, 1996 and March 4-5, 1997,

prepared for Trus-Joist MacMillan, by Braun Intertec Corporation, Report No. CMXX-96-0984,

April 1, 1997.

108. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part I -

Plywood, Technical Bulletin No. 768, National Council of the Paper Industry for Air and Stream

Improvement, Inc., Research Triangle Park, NC, 1999.

109. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part II -

Engineered Wood Products, Technical Bulletin No. 769, National Council of the Paper Industry

for Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.

110. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part III -

Medium Density Fiberboard, Technical Bulletin No. 770, National Council of the Paper Industry

for Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.
6.0 References

6-11

111. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part IV -

Particleboard, Technical Bulletin No. 771, National Council of the Paper Industry for Air and

Stream Improvement, Inc., Research Triangle Park, NC, 1999.

112. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part V -

Oriented Strandboard, Technical Bulletin No. 772, National Council of the Paper Industry for

Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.

113. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part VI -

Hardboard/Fiberboard, Technical Bulletin No. 773, National Council of the Paper Industry for

Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.

114. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part VII

- Test Methods, Quality Assurance/Quality Control Procedures and Data Analysis Protocol,

Technical Bulletin No. 774, National Council of the Paper Industry for Air and Stream

Improvement, Inc., Research Triangle Park, NC, 1999.

115. Wood Products MACT Study Database, National Council of the Paper Industry for Air and

Stream Improvement, Inc., Research Triangle Park, NC, 1999.

116. Comparison of EPA M0011 and NCASI Impinger Method Emission Factors for Formaldehyde,

memorandum to project file, from D. Bullock, Midwest Research Institute, November 4, 1999.

117. Field Validation of the DNPH Method for Aldehydes and Ketones, EPA No. 68-D4-0022, DCN

No. 95-650-049-12-04, prepared for J. Knoll, National Exposure Research Laboratory, Air

Measurements Research Division, Methods Branch, U.S. Environmental Protection Agency,

Research Triangle Park, NC, January 30, 1996.

118. Memorandum from G. McAlister, EMAD/EMC, to D. Safriet, EMAD/EFIG. California Air

Resources Board (CARB) Method 430. February 7, 2001.

119. Procedures for Preparing Emission Factor Documents, EPA-454/R-95-015, U.S. Environmental

Protection Agency, Research Triangle Park, NC, May 1997.

120. Approach to Reviewing Test Reports Submitted With Responses to the 1998 EPA Information

Collection Request (MACT Survey)–Plywood and Composite Wood Products, to Mary Tom

Kissell, OAQPS/ESD/WCPG, from D. Bullock, Midwest Research Institute, June 8, 1999.

121. Approach to Using Values Below Test Method Detection Limits in the Development of Emission

Factors and Control Efficiencies, to Mary Tom Kissell, OAQPS/ESD/WCPG, from D. Bullock,

Midwest Research Institute, November 3, 1999.
6.0 References

6-12

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Attachment 1

Acronyms/Codes/Abbreviations
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Table 1. Emission Test Method Codes

Code Test Method Pollutant(s) Measureda

1,2-PP 1-(2-pyridyl) piperazine method Methylene diphenyl diisocyanate (MDI)

BCA Bacharach combustion analyzer Carbon monoxide

CARB430 California Air Resources Board

Method 430

Formaldehyde

DNPH Unspecified DNPH method Formaldehyde

GC Unspecified gas chromatography Methane

GC/FID Unspecified gas

chromatography/flame ionization

detector method

Ethane, methane

M0010 SW-846 Method 0010, Semi-VOST

(Semivolatile Organic Sampling

Train)

1,2,4-trimethylbenzene, acetophenone, a-pinene,

a-terpene, biphenyl, bis-(2-ethylhexyl phthalate),

b-pinene, butylbenzyl phthalate, cumene, p-cymene,

di-N-butyl phthalate, hydroquinone

M0011 BIF Method 0011, for Aldehydes

and Ketones

2,5-dimethyl benzaldehyde, acetaldehyde, acetone,

acrolein, benzaldehyde, butylaldehyde, butyraldehyde,

crotonaldehyde, formaldehyde, hexaldehyde,

isovaleraldehyde, methyl ethyl ketone, o-,m-,ptolualdehyde, propionaldehyde, valeraldehyde

M0030 SW-846 Method 0030, VOST

(Volatile Organic Sampling Train)

1,1,1-trichloroethane, 4-methyl-2-pentanone, a-pinene,

acetone, b-pinene, benzene, bromomethane, carbon

disulfide, carbon tetrachloride, chloroform,

chloromethane, cumene, dimethyl sulfide, ethyl

benzene, n-hexane, methyl ethyl ketone, methylene

chloride, p-cymene, styrene, toluene, o-,m-,p-xylene

M10 EPA Method 10 Carbon monoxide

M10B EPA Method 10B Carbon monoxide

M18 EPA Method 18 Benzene, methane

M201A EPA Method 201A PM-10

M202 EPA Method 202 Condensible PM

M25A EPA Method 25A Total hydrocarbons (THC)

M3 EPA Method 3 Carbon dioxide

M3A EPA Method 3A Carbon dioxide

M308 EPA Method 308 Methanol

M5 EPA Method 5 Filterable PM

M6 EPA Method 6 Sulfur dioxide
Table 1. (continued)

Attachments

Code Test Method Pollutant(s) Measureda

A-4

M6C EPA Method 6C Sulfur dioxide

M7 EPA Method 7 Nitrogen oxides

M7C EPA Method 7C Nitrogen oxides

M7E EPA Method 7E Nitrogen oxides

MM5 Modified EPA Method 5 Phenol

MM0011 Modified BIF Method 0011, for

Aldehydes and Ketones

Formaldehyde

NCASI NCASI impinger method Formaldehyde, methanol

NICM NCASI impinger/canister method Acetaldehyde, acetone, acrolein, a-pinene, b-pinene,

benzene, bromomethane, camphene, 3-carene,

chloroethane, chloroethene, cis-1,2-dichloroethylene,

cumene, 1,2-dichloroethane, formaldehyde, limonene,

p-mentha-1,5-diene, methanol, methyl ethyl ketone,

methyl isobutyl ketone, methylene chloride, p-cymene,

phenol, propionaldehyde, styrene, toluene,

1,2,4-trichlorobenzene, o-,m-,p-xylene

P&CAM142 NIOSH Physical and Chemical

Analytical Method 142

Methylene diphenyl diisocyanate (MDI)

TO-5 TO-5 (Compendium of Methods for

the Determination of Toxic Organic

Compounds in Ambient Air)

2,4-dimethylbenzaldehyde, acetone, benzaldehyde,

butyraldehyde, crotonaldehyde, formaldehyde, 

hexaldehyde, isovaleraldehyde, o-,m-,p-tolualdehyde,

valeraldehyde

TO-8 TO-8 (Compendium of Methods for

the Determination of Toxic Organic

Compounds in Ambient Air)

Benzo-a-pyrene, o-,m-,p-cresol, naphthalene, phenol,

pyridine

TO-14 TO-14 (Compendium of Methods for

the Determination of Toxic Organic

Compounds in Ambient Air)

Acetone, benzene, bromomethane, chloroethane,

chloromethane, ethanol, ethylbenzene, isobutanol,

methyl ethyl ketone, methyl propyl ketone, methylene

chloride, propanol, styrene, toluene,

trichlorofluoromethane, xylenes

TO-14(mod) Modification of TO-14 Methanol

a

 HAP compounds in italic.
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Table 2. HAP Analytes and Analysis Techniques for

NCASI MACT Sampling Program

HAP Analyte

Analysis Methoda

Impinger Canister

Acetaldehyde GC/FID GC/MS

Acrolein GC/FID GC/MS

Benzene none GC/MS

Bromomethane none GC/MS

Chloroethane none GC/MS

Chloroethene none GC/MS

Cumene none GC/FID

1,2-Dichloroethane none GC/MS

Formaldehyde Colorimetric none

Methanol GC/FID GC/MS

Methyl Ethyl Ketone GC/FID GC/MS

Methyl Isobutyl Ketone GC/FID GC/MS

Methylene Chloride none GC/MS

Phenol GC/FID GC/MS

Propionaldehyde GC/FID GC/MS

Styrene none GC/MS

Toluene none GC/MS

1,2,4-Trichlorobenzene none GC/MS

m,p-Xylene none GC/MS

o-Xylene none GC/MS

a GC/FID = gas chromatography/flame ionization detector; GC/MS = gas

chromatography/mass spectrometer.

Table 3. Non-HAP Analytes and Analysis Techniques for

NCASI MACT Sampling Program

Non-HAP Analyte

Analysis Methoda

Impinger Canister

Acetone GC/FID GC/MS

Camphene none GC/FID

3-Carene none GC/FID

p-Cymene none GC/FID

cis-1,2-Dichloroethylene none GC/MS

Limonene none GC/FID

p-mentha-1,5-Diene none GC/FID

Alpha-pinene none GC/FID

Beta-pinene none GC/FID

a GC/FID = gas chromatography/flame ionization detector; GC/MS = gas

chromatography/mass spectrometer.
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Table 4. Product Codes

Code Product

FB Fiberboard

HB Hardboard

HPW Hardwood Plywood

I-joist I-joist

LSL Laminated Strand Lumber

Lumber Lumber

LVL Laminated Veneer Lumber

MDF Medium Density Fiberboard

OSB Oriented Strandboard

PB Particleboard

SPW Softwood Plywood

Table 5. Air Pollution Control Device (APCD) Codes

Code Air Pollution Control Device

BH Baghouse (Fabric Filter)

BIO Biofilter

CU Combustion Unit; Exhaust Gas Recirculation

CYC Cyclone

DESP Dry Electrostatic Precipitator

EFB Electrified Filter Bed

MC Multicyclone (Multiclone)

NONE None; no air pollution control device

RCO Regenerative Catalytic Oxidizer

RTO Regenerative Thermal Oxidizer

SCBR Wet Scrubber

SF Sand Filter

TO Thermal Oxidizer

WESP Wet Electrostatic Precipitator
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Table 6. Wood Species Codes

Code Wood Species

ALDER Alder

ASPEN Aspen

BIRCH Birch

CBI Wood species is claimed to be Confidential Business Information

CHERRY Cherry

DFIR Douglas Fir

DFIR-fresh Douglas Fir - fresh cut

DFIR-7day old Douglas Fir - cut 7 days before testing

DFIR HEART Douglas Fir Heartwood

DFIR SAP Douglas Fir Sapwood

GUM Unspecified Gum

HICKORY Hickory

HWOOD Unspecified Hardwood

LARCH Larch

MAPLE Maple

MIXED Mixed hardwood and softwood species

NPINE Northern Pine

NS Not Specified

OAK Oak

PINE Unspecified Pine

POPLAR Poplar

PPINE Ponderosa Pine

ROAK Red Oak

SPRUCE Spruce

SWOOD Unspecified Softwood

SYPINE Southern Yellow Pine

UFIR Unspecified Fir

USPINE Unspecified Southern Pine

WFIR White Fir

WOAK White Oak

WSWOOD Western Softwood

YPOPLAR Yellow Poplar
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Table 7. Resin Codes

Code Resin Type

LINSEED Linseed Oil Binder System

MDI Methylene diphenyl diisocyanate

PF Phenol-Formaldehyde

PF-dry Dry Phenol-Formaldehyde

UF Urea-Formaldehyde

Table 8. Dryer Firing Type Codes

Code Dryer Firing Type

DF Direct-Fired

IF Indirect Heated

IF/DF Indirect and Direct Heat

RF Radio-Frequency Heated

Table 9. Dryer Fuel Type Codes

Code Dryer Fuel Type

DFINE Dry Wood Fines (unspecified)

FINES Wood Fines (unspecified)

NGAS Natural Gas

PROP Propane

SDUST Sanderdust

STEAM Steam Heated (indirect heated)

TRIM Wood Trim

WDUST Wood Dust (unspecified)

WREF Wood Refuse (unspecified)
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Table 10. Dryer Hot Air Source Codes

Code Dryer Hot Air Source

BOILER FLUE GAS Boiler Flue Gas

BOTH Indirect and Direct Heat

DFIRE Direct-Fired (unspecified)

FLUE GAS Flue Gas

FUEL CELL Fuel Cell

GAS BU Gas Burner

IHEAT Indirect heated

RFREQ Radio-Frequency Heated

STEAM Steam (indirect heat)

STM COIL Steam Coil (indirect heat)

SUSP BU Suspension Burner

TOH Thermal Oil Heater

WET CELL Wet Cell

Table 11. Veneer Dryer Type Codes

Code Veneer Dryer Type

LONG Longitudinal

JET Jet

PLATEN Platen

RF Radio-Frequency Heated

TUNNEL Tunnel
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Table 12. Emission Factor Unit Abbreviations

Emission Factor

Unit Abbreviation

Definition

lb/1000 ft3 pounds per thousand cubic feet

lb/MLF pounds per thousand linear feet

lb/MSF pounds per thousand square feet of surface area

lb/MSF reclaim pounds per thousand square feet of reclaimed material surface area

lb/MSF 1/2 pounds per thousand square feet of 1/2-inch thick board

lb/MSF 1/8 pounds per thousand square feet of 1/8-inch thick board

lb/MSF 3/4 pounds per thousand square feet of 3/4-inch thick board

lb/MSF 3/8 pounds per thousand square feet of 3/8-inch thick board

lb/ODT pounds per oven-dried ton
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Attachment 2

Example Calculation
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Example Calculation

Unit Operation

Test

date

No. of

runs

No. of

runs

BDL

Test emission factor value

(average of test runs),

lb/ODT

Unit emission factor

value, lb/ODT

Plant 30, dryer A 1/19/93 3 0 0.000413 0.000413

Plant 10, dryer A 10/22/97 3 3 0.008121 0.008121a

Plant 10, dryer B 10/22/97 3 3 0.003042 0.003042

Plant 156, dryer A 9/22/97 6 0 0.006574

Plant 156, dryer A 9/22/97 3 0 0.007652 0.007113

Plant 183, dryer A 5/2/97 3 2 0.003555

Plant 183, dryer A 5/2/97 3 0 0.005773 0.004664

Plant 30, dryer B 1/20/93 3 0 0.002676 0.002676

Overall emission factor for unit operation (average of unit emission factor values),

lb/ODT

0.0036

a This unit average emission factor was disregarded when calculating the overall emission factor for the unit

operation. This value is one-half of the MDL for a test where all runs were non-detect, and is higher than all of the

other detect runs. Using this value would bias the overall average emission factor high.
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Attachment 3

Conversion Factors and Equations
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Useful Conversion Factors

To convert from . . . to . . . multiply by . . .

board feet cubic feet 0.0833

lb as carbon lb as propane 1.22

lb as methane lb as carbon 0.75

lb as propane lb as carbon 0.82

MSF “X” basis MSF “Y” basis X/Y (see example below)

ppm as carbon ppm as propane 0.33

ppm as methane ppm as carbon 1

ppm as propane ppm as carbon 3.0

Example of conversion from MSF 3/4-inch basis to MSF 3/8-inch basis:

1,000 MSF 3/4-inch basis = 1,000 MSF 3/8-inch basis × (3/4)/(3/8) = 2,000 MSF 3/8-inch basis
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Useful Equations

Wood moisture content calculations:

% Moisture Content (dry basis) =

weight of water in wood

× 100

weight of oven-dry wood

% Moisture Content (dry basis) =

%MCWB ÷ 100

× 100

1 ! (%MCWB ÷ 100)

% Moisture Content (wet basis) =

weight of water in wood

× 100

weight of wet wood

% Moisture Content (wet basis) =

%MCDB ÷ 100

× 100

1 + (%MCDB ÷ 100)

where:

%MCDB = moisture content (dry basis)

%MCWB = moisture content (wet basis)

Parts per million by volume, dry:

ppmvd =

ppmvw

1 ! (%moisture ÷ 100)

where:

ppmvd = concentration, parts per million by volume, dry

ppmvw = concentration, parts per million by volume, wet

%moisture = stack gas moisture content, %

Grains/dscf from grams collected:

gr/dscf =

grams × 15.43

dscf

where:

gr/dscf = concentration, grains per dry standard cubic foot

grams = grams of pollutant collected

dscf = gas volume sampled, dry standard cubic feet
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Stack gas flowrate, dry standard cubic feet per minute:

dscfm = acfm × (1 ! (%moisture ÷ 100) × (68 + 460) ×

barometric pressure

(stack temp + 460) × 29.92

where:

dscfm = stack gas flow rate, dry standard cubic feet per minute

acfm = stack gas flow rate, actual cubic feet per minute

%moisture = stack gas moisture content, %

barometric pressure = stack pressure, inches of mercury

stack temp = stack gas temperature, degrees Fahrenheit

Lb/hr from grains/dscf:

lb/hr = (dscfm × gr/dscf) ×

60

7000

where:

lb/hr = emission rate, pounds of pollutant per hour

dscfm = stack gas flowrate, dry standard cubic feet per minute

gr/dscf = pollutant concentration, grains per dry standard cubic foot

Lb/hr from ppmvd:

lb/hr = MW × (ppmvd × 0.000001) × dscfm ×

60

385.3

where:

lb/hr = emission rate, pounds of pollutant per hour

MW = molecular weight of pollutant

ppmvd = concentration, parts per million by volume, dry

dscfm = stack gas flowrate, dry standard cubic feet per minute

Lb/hr from %:

lb/hr = MW × (concentration% ÷ 100) × 60 ×

dscfm

385.3

where:

lb/hr = emission rate, pounds of pollutant per hour

MW = molecular weight of pollutant

concentration% = concentration of pollutant, percent

dscfm = stack gas flowrate, dry standard cubic feet per minute

Emission factor:

emission factor = emission rate, lb/hr ÷ process rate, units/hr
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Control efficiency:

Control efficiency =

inlet mass emissions ! outlet mass emissions

× 100

inlet mass emissions

Conversion from THC-as-carbon to THC-as-propane:

THC as pounds carbon × 44 pounds propane

36 pounds carbon = THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

Calculation of VOC-as-propane from THC-as-carbon:

VOC as propane = (1.22 × THC as carbon) + formaldehyde ! (acetone + methane + methylene chloride)
1/2002 Wood Products Industry 10.5-1

10.5 Plywood Manufacturing

10.5.1 General

Plywood is a building material consisting of veneers (thin wood layers or plies) bonded with an

adhesive. There are two types of plywood: softwood plywood and hardwood plywood. Softwoods

generally correspond to coniferous species. The most commonly used softwoods for manufacturing

plywood are firs and pines. Hardwoods generally correspond to deciduous species. For hardwood

plywood, commonly used wood species include oak, poplar, maple, cherry, and larch. 

Softwood plywood is manufactured by gluing several layers of dry softwood veneers together

with an adhesive. Softwood plywood is used for wall siding, sheathing, roof decking, concrete

formboards, floors, and containers. Softwood plywood is classified under Standard Industrial

Classification (SIC) code 2436, and North American Industrial Classification System (NAICS) code

321212 for “Softwood Plywood and Veneer”.

Hardwood plywood is made of hardwood veneers bonded with an adhesive. The outer layers

(face and back) surround a core which is usually lumber, veneer, particleboard, or medium density

fiberboard. Hardwood plywood may be pressed into panels or plywood components (e.g., curved

hardwood plywood, seat backs, chair arms, etc.). Hardwood plywood is used for interior applications

such as furniture, cabinets, architectural millwork, paneling, flooring, store fixtures, and doors. Hardwood

plywood is classified under SIC code 2435 and NAICS code 321211, for “Hardwood Plywood and

Veneer”.

Softwood plywood plants typically produce softwood veneers and softwood plywood on the same

plant site. However, most hardwood plywood and veneer plants either produce hardwood plywood or

hardwood veneer. Hardwood veneer plants cut and dry hardwood veneers. Hardwood plywood plants

typically purchase hardwood veneers and press the veneers onto a purchased core material.

10.5.2 Process Description1-4, 22

The manufacture of softwood or hardwood plywood consists of nine main processes: log storage,

log debarking and bucking, heating the logs, peeling the logs into veneers, drying the veneers, gluing the

veneers together, pressing the veneers in a hot press, plywood cutting, and other finishing processes such

as sanding. Figure 10.5-1 provides a generic process flow diagram for a plywood mill.

The initial step of debarking is accomplished by feeding logs through one of several types of

debarking machines. The purpose of this operation is to remove the outer bark of the tree without

substantially damaging the wood. After the bark is removed, the logs are cut to appropriate lengths in a

step known as bucking.

The logs (now referred to as blocks) then are heated to improve the cutting action of the veneer

lathe or slicer, thereby generating a product from the lathe or slicer with better surface finish. Blocks are

heated to around 93°C (200°F) using a variety of methods--hot water baths, steam heat, hot water spray,

or a combination of the three.
10.5-2 EMISSION FACTORS 1/2002

VENEER DRYING

LOG

STORAGE

(SCC 3-07-008-95)

LOG HEATING 

(STEAMING/SOAKING)

(SCC 3-07-007-30)

(SCC 3-07-007-89)

LOG DEBARKING

(SCC 3-07-008-01)

AND BUCKING

(SCC 3-07-008-02)

VENEER

LAYUP AND

GLUE SPREADING

(SCC 3-07-007-27)

VENEER CUTTING

(SCC 3-07-007-25)

FINISHED

PRODUCT

PLYWOOD

FINISHING

(SCC 3-07-007-02)

PLYWOOD

CUTTING

(SCC 3-07-007-10)

PLYWOOD

PRESSING

(SCC 3-07-007-80 TO -85)

(SCC 3-07-007-11 TO -20)

(SCC 3-07-007-34 TO -71)

Additional Source Classification Codes for Combined Operations:

SCC 3-07-007-88: Hardwood plywood combined dust baghouse (includes trim saw, composer, core saw, dry 

hog, hammermill, and sander)

SCC 3-07-007-90: Softwood plywood, dry veneer trim chipper (trimmed veneer from layup line)

SCC 3-07-007-91: Softwood plywood, dry plywood trim chippers (trim from panel saws)

SCC 3-07-007-92: Softwood plywood sander (includes sanders and specialty saw)

SCC 3-07-007-93: Softwood plywood saws (includes 3 saws, hog, and sander)

Figure 10.5-1. Generic process flow diagram for a plywood mill.

(SCC = Source Classification Code.)

After heating, the logs are processed to generate veneer. For most applications, a veneer lathe is

used, but some decorative, high quality veneer is generated with a veneer slicer. The slicer and veneer

lathe both work on the same principle; the wood is compressed with a nosebar while the veneer knife cuts

the blocks into veneers that are typically 3 mm (1/8 in.) thick. Decorative hardwood veneers are usually

sliced much thinner than 3 mm (1/8 in.) thick. The veneer pieces are then clipped to a usable width,

typically 1.37 m (54 in.), to allow for shrinkage and trim.

Veneers are taken from the clipper to a veneer dryer where they are dried to moisture contents

that range from around 1 to 15 percent, dry basis. Face veneer moisture contents can range up to 25

percent, dry basis. Target moisture content depends on the type of resin used in subsequent gluing steps. 

The typical drying temperature ranges from 150° to 200°C (300° to 400°F). The veneer dryer may be a

longitudinal dryer, which circulates air parallel to the veneer, or a jet dryer. The jet dryers direct hot, high

velocity air at the surface of the veneers in order to create a more turbulent flow of air. The increased

turbulence provides more effective use of dryer energy, thereby reducing drying time. Veneer dryers

may be either direct-fired or indirect-heated. In direct-fired dryers, hot combustion gases from an onsite

boiler are blended with recirculated exhaust from the dryer to lower the gas temperature. In indirectheated veneer dryers, air is warmed over steam coils and circulated over the veneer. Veneer dryers

typically have one to three heated zones followed by a cooling zone or section. Each heated zone has a

hot air source, fans to move the warm air, and an exhaust vent or stack. The cooling section circulates

ambient air over the veneer to reduce the veneer temperature just before it exits the dryer. The veneers

must be cooled to prevent glue from curing on the veneers during the layup and glue spreading operations

before they reach the plywood press.
1/2002 Wood Products Industry 10.5-3

Veneer may also be dried in veneer kilns, which resemble lumber kilns. Kiln drying is a batch

operation, where the veneers are stacked with stickers (narrow wood strips) and dried in the kiln.

Veneer moisture is checked against the target moisture level as the veneer exits the veneer dryer. 

Veneer redryers may be used to redry the veneer that did not reach the target moisture content. Veneer

redryers are typically heated by radio frequency (RF) and are designed to handle only a fraction of the

throughput from full-scale veneer dryers. Conventional veneer dryers may also be used for redrying

veneer. When used for redrying veneer, conventional veneer dryers are operated at faster than normal

speeds (i.e., the redry veneer passes through the dryer more quickly than does green veneer).

After drying, veneers sometimes are glued together on the edges to form larger sheets of veneer. 

This process is called composing. Narrow veneer slices must be composed before they are used in

plywood panels or other products requiring wider veneer sheets.

When the veneers have been dried to their specified moisture content, they are conveyed to a

layup operation, where a thermosetting resin is spread on the veneers. The two main types of resins are

phenol-formaldehyde, which is used for softwood plywood and exterior grades of hardwood plywood, and

urea-formaldehyde, which is used to glue interior grades of hardwood plywood. The resins are applied by

glue spreaders, curtain coaters, or spray systems. Spreaders have a series of rubber-covered grooved

application rolls that apply the resin to the sheet of veneer. Generally, resin is spread on two sides of one

ply of veneer, which is then placed between two plies of veneer that are not coated with resin.

Assembly of the plywood panels must be symmetrical on either side of a neutral center in order to

avoid excessive warpage. For example, a five-ply panel would be laid up in the following manner. A

back, with the grain direction parallel to the long axis of the panel, is placed on the assembly table. The

next veneer has a grain direction perpendicular to that of the back, and is spread with resin on both sides. 

Then, the center is placed, with no resin, and with the grain perpendicular to the previous veneer (parallel

with the back). The fourth veneer has a grain perpendicular to the previous veneer (parallel with the

short axis of the panel) and is spread with resin on both sides. The final, face, veneer with no resin is

placed like the back with the grain parallel to the long axis of the plywood panel.

The laid-up assembly of veneers then is sent to a hot press in which it is consolidated under heat

and pressure. Hot pressing has two main objectives: (1) to press the glue into a thin layer over each

sheet of veneer; and (2) to activate the thermosetting resins. Typical press temperatures range from 132°

to 165°C (270° to 330°F) for softwood plywood, and 107° to 135°C (225° to 275°F) for hardwood

plywood. Press times generally range from 2 to 7 minutes. The time and temperature vary depending on

the wood species used, the resin used, and the press design.

The plywood then is taken to a finishing process where edges are trimmed; the face and back

may or may not be sanded smooth. The type of finishing depends on the end product desired.

10.5.3 Emissions and Controls2-22

The primary emissions from the manufacture of plywood include filterable particulate matter

(PM) and PM less than 10 micrometers in aerodynamic diameter (PM-10) from log debarking and

bucking, and plywood cutting and sanding; filterable and condensible PM/PM-10 from drying and

pressing; organic compounds from steaming and drying operations; and organic compounds, including

formaldehyde and other hazardous air pollutants (HAPs), from gluing and hot pressing. However, trace
10.5-4 EMISSION FACTORS 1/2002

amounts of combustion by-products, which may include HAPs, may be present in direct-fired veneer

dryer exhausts as a result of fossil fuel or wood combustion gases being passed through the dryer. Fuel

combustion for material drying also can generate carbon monoxide (CO), carbon dioxide (CO2), sulfur

dioxide (SO2), and nitrogen oxide (NOx) emissions.

The main source of emissions is the veneer dryer, which emits significant quantities of organic

compounds. The quantity and type of organic compounds emitted varies depending on the wood species,

the dryer type, and its method of operation. Emissions from dryer heated zones and cooling sections

typically are ducted through separate stacks. In addition to emissions from the heated zones and cooling

section stacks, veneer dryer fugitive emissions may be emitted from the dryer ends and doors. The two

discernible fractions released from the dryer are condensibles and volatiles. As the condensible

compounds cool after being emitted from the stack, they often combine with water vapor to form

aerosols, which can cause a blue haze. 

Measurement of VOC and condensible PM emission rates are highly dependent on stack gas and

sampling train filter temperatures. When the sampling train filter temperature is higher than the stack gas

temperature, the rate of VOC and condensible PM emissions measured will increase with increasing filter

temperature, because, as filter temperature increases, less organic material will condense on the sampling

train filter. The available data are inadequate to determine the effect on emissions of recirculating the

exhaust from wood-fired veneer dryers to a combustion gas blend box.

The hot pressing operation is also a source of organic emissions. The quantity and composition of

emissions from this operation are expected to vary with wood species and resin components. Plywood

pressing operations are typically uncontrolled.

Significant quantities of sawdust and other small wood particles are generated by plywood cutting

and sanding operations. Sanders and trim saws typically have control devices to recover the material for

use as a fuel in the dryer or boiler. However, small amounts of PM may be released from cutting and

sanding. Log debarking, log bucking, and sawdust handling are additional sources of PM emissions. 

Wood storage piles are sources of fugitive PM and VOC emissions. Log debarking, log peeling, and other

minor operations are also sources of fugitive VOC emissions.

Methods of controlling PM emissions from veneer dryers include absorption systems (wet

scrubbers), electrified filter beds (EFBs), wet electrostatic precipitators (WESPs), and oxidation systems

(discussed below). The EFB uses electrostatic forces to attract pollutants to an electrically charged

gravel bed. The WESP uses electrostatic forces to attract pollutants to either a charged metal plate or a

charged metal tube. The collecting surfaces are continually rinsed with water to wash away the

pollutants. Wet PM control systems such as wet scrubbers and WESPs may achieve short-term

reductions in emissions of some water-soluble organic compounds (such as formaldehyde). However, the

ability of these wet systems to absorb water-soluble compounds diminishes as the recirculating scrubbing

liquid becomes saturated with these compounds.

A VOC control technology commonly used in the wood products industry for controlling veneer

dryer exhaust gases is regenerative thermal oxidation. Thermal oxidizers destroy VOCs and condensible

organics by burning them at high temperatures. Thermal oxidizers also reduce CO emissions in directfired dryer exhausts by oxidizing the CO in the exhaust to CO2

 (a product of complete combustion). 

Regenerative thermal oxidizers (RTOs) are designed to preheat the inlet emission stream with heat

recovered from the incineration exhaust gases. Up to 98 percent heat recovery is possible, although
1/2002 Wood Products Industry 10.5-5

95 percent is typically specified. Gases entering an RTO are heated by passing through pre-heated beds

packed with a ceramic media. A gas burner brings the preheated emissions up to an incineration

temperature between 788° and 871°C (1450° and 1600°F) in a combustion chamber with sufficient gas

residence time to complete the combustion. Combustion gases then pass through a cooled ceramic bed

where heat is extracted. By reversing the flow through the beds, the heat transferred from the

combustion exhaust air preheats the gases to be treated, thereby reducing auxiliary fuel requirements.

Regenerative catalytic oxidizers (RCOs) are also used to control VOCs from veneer dryers. 

Regenerative catalytic oxidizers function similar to RTOs, except that the heat recovery beds in RCOs

contain catalytic media. The catalyst accelerates the rate of VOC oxidation and allows for VOC

destruction at lower temperatures than in an RTO, typically 316° to 538°C (600° to 1000°F), which

reduces auxiliary fuel usage. 

In addition to add-on thermal or catalytic oxidizers, exhaust gases from veneer dryers may be

routed to the combustion chamber of an onsite boiler or process heater. The VOC and CO emissions in

the process exhaust may be incinerated in the combustion chamber provided that the system is designed

to allow for sufficient mixing and residence time.

Fugitive PM emissions from road dust and uncovered bark and dust storage piles may be

controlled in a number of different ways. Some of these methods include enclosure, wet suppression

systems, and chemical stabilization.

Calculating PM-10 emissions from wood products industry emission sources is problematic due to

the relationship between PM-10 (or PM) emissions and VOC emissions from these processes. Because

the Method 201A train (PM-10) operates with an in-stack cyclone and filter, organic materials that are

volatile at stack gas temperatures but that are condensed at back half impinger temperatures (-20°C

[-68°F]) are collected as condensible PM-10. However, these materials will also be measured as VOC

via Methods 25 and 25A, which operate with a heated or an in-stack filter. Hence, if PM-10 is calculated

as the sum of filterable and condensible material, some pollutants will be measured as both PM-10 and

VOC emissions. However, if only filterable material is considered to be PM-10, the PM-10 emission

factors will be highly dependent on stack gas temperature. In this AP-42 section, PM-10 is reported as

front half catch only (Method 201A results only; not including Method 202 results). However,

condensible PM results are also reported, and these results can be combined with the PM-10 results as

appropriate for a specific application. Measured VOC emissions may be affected by the sampling

method and by the quantity of formaldehyde and other aldehydes and ketones in the exhaust;

formaldehyde is not quantified using Method 25A. Other low molecular weight oxygenated compounds

have reduced responses to Method 25A. Therefore, when VOC emissions are measured using

Method 25A, the emission rates will be biased low if low molecular weight oxygenated compounds are

present in significant concentrations in the exhaust stream. A more extensive discussion of these

sampling and analysis issues is provided in the Background Report (Reference 15) for this section.

Guidance from EPA’s Emission Factor and Inventory Group (EFIG) indicates that when it is

possible, VOC emission factors should be reported in terms of the actual weight of the emitted compound. 

However, when an actual molecular weight (MW) of the emitted stream is not feasible (as is the case

with the mixed streams emitted from wood products industry sources), the VOC should be reported using

an assumed MW of 44, and reported “as propane.” Each VOC-as-propane emission factor is estimated

by first converting the THC from a carbon basis to a propane basis. Propane (MW = 44) includes 3

carbon atoms (total MW of 36) and 8 hydrogen atoms (total MW of 8). Every 36 pounds of carbon
10.5-6 EMISSION FACTORS 1/2002

measured corresponds to 44 pounds of propane. The ratio of the MW of propane to the MW of carbon in

propane is 44/36, or 1.22. The conversion is expressed by the following equation:

THC as pounds carbon × 44 pounds propane

36 pounds carbon

= THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

After the THC emission factor has been converted from a carbon to a propane basis, the

formaldehyde emission factor is added (where available), then the available emission factors for

non-VOC compounds, including acetone, methane, and methylene chloride, are subtracted. This

procedure is expressed simply by the following equation:

VOC as propane = (1.22 × THC as carbon) + formaldehyde - (acetone + methane + methylene chloride)

In cases where no emission factor is available (or the emission factor is reported only as below the test

method detection limit, or “BDL”) for one or more of the compounds used to estimate the VOC-aspropane value, adjustments to the converted THC value are made only for those compounds for which

emission factors are available. That is, a value of zero is inserted in the above equation for the specified

compounds where no emission factor is available, or where the emission factor is reported only as BDL. 

For example, if no methane emission factor is available, the THC-as-carbon emission factor is converted

to THC-as-propane, formaldehyde is added, and only acetone and methylene chloride are subtracted.

Table 10.5-1 presents emission factors for veneer dryer emissions of PM, including filterable PM

and condensible PM. Table 10.5-2 presents emission factors for veneer dryer emissions of NOx, CO, and

CO2. Table 10.5-3 presents emission factors for veneer dryer emissions of organic compounds, some of

which are listed as HAPs under section 112(b) of the Clean Air Act. The emission factors for dryer

emissions are presented in units of pounds of pollutant per thousand square feet of 3/8-inch thick panel

produced (lb/MSF 3/8). Separate emission factors are presented for hardwood plywood and softwood

plywood veneer dryers. In Tables 10.5-2 and -3, separate emission factors also are presented for the

heated zones and cooling section of a veneer dryer. When estimating total emissions from the drying

process, emissions from heated zones and cooling section should be combined. 

Table 10.5-4 presents emission factors for plywood press emissions of PM, including filterable

PM and condensible PM. Table 10.5-5 presents emission factors for plywood press emissions of NOx,

CO, and CO2. Table 10.5-6 presents emission factors for plywood press emissions of organic

compounds, some of which are HAPs. The units for the press emission factors are pounds of pollutant

per thousand square feet of 3/8-inch thick panel produced (lb/MSF 3/8). Table 10.5-7 presents emission

factors for organic compounds from miscellaneous plywood manufacturing sources. Some of these

compounds are listed HAPs under section 112(b) of the Clean Air Act.
1/2002 Wood Products Industry 10.5-7

Table 10.5-1. EMISSION FACTORS FOR PLYWOOD VENEER DRYERS--

PARTICULATE MATTERa

Source

Emission

Control 

Devicec

Filterableb

Condensibled

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Indirect heated,

heated zones,

softwood

(SCC 3-07-007-62)

Uncontrolled 0.35 D ND 1.0 D

Direct natural gasfired, heated zones,

softwood

(SCC 3-07-007-52)

Uncontrolled 0.079 D ND 0.42 D

Direct wood-fired,

heated zones,

softwood

(SCC 3-07-007-36)

WESP 0.24 D ND ND

Radio frequencyheated redryer,

softwood

(SCC 3-07-007-71)

Uncontrolled 0.0050 E ND 0.0060 E

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick veneer

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. SCC = Source Classification Code. ND = no data available. Reference 16. See Table 10.5-8

for the hardwood and softwood species commonly used in the production of plywood and other

composite wood products. Note: emission factors in table represent averages of data sets. 

The data spreadsheets, which may be more useful for specific applications, are available on

EPA’s Technology Transfer Network (TTN) website at: http://www.epa.gov/ttn/chief/.

b Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent) sampling

train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the cyclone and

filter of an EPA Method 201 or 201A sampling train.

c Emission control device: WESP = wet electrostatic precipitator.

d Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).
10.5-8 EMISSION FACTORS 1/2002

Table 10.5-2. EMISSION FACTORS FOR PLYWOOD VENEER DRYERS--NOx, CO, AND CO2 a

Source

Emission

Control

Deviceb NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Indirect heated, heated

zones, softwood

(SCC 3-07-007-62)

Uncontrolled

RTO

ND

ND

0.028c

0.062c

E

E

ND

ND

Indirect heated, cooling

section, softwood

(SCC 3-07-007-63)

Uncontrolled ND 0.043c E ND

Indirect heated, heated

zones, hardwood

(SCC 3-07-007-56)

Uncontrolled ND 0.0088c E ND

Indirect heated, cooling

section, hardwood

(SCC 3-07-007-57)

Uncontrolled ND 0.099c E ND

Direct natural gasfired, heated zones,

softwood

(SCC 3-07-007-52)

Uncontrolled

RCO

0.012d

ND

D 0.64e

0.0076c

D

E

28f

ND

D

Direct natural gasfired, cooling section,

softwood

(SCC 3-07-007-53)

Uncontrolled ND 0.010c E ND

Direct wood-fired,

heated zones,

softwood

(SCC 3-07-007-36)

Uncontrolled 0.17g D 3.2g D 100h D

Direct wood-fired,

heated zones,

hardwood

(SCC 3-07-007-34)

Uncontrolled ND 0.23c E ND

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick veneer

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. Factors for heating zones and cooling section should be summed when estimating total dryer

emissions. SCC = Source Classification Code. ND = no data available. See Table 10.5-8 for the

hardwood and softwood species commonly used in the production of plywood and other composite

wood products. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s TTN

website at: http://www.epa.gov/ttn/chief/.

b Emission control device: RTO = regenerative thermal oxidizer; RCO = regenerative catalytic oxidizer.

c Reference 17.

d Reference 16.

e References 16 and 17.
1/2002 Wood Products Industry 10.5-9

Table 10.5-2 (cont.).

f Reference 18.

g References 16 and 19.

h Reference 19.
10.5-10 EMISSION FACTORS 1/2002

Table 10.5-3. EMISSION FACTORS FOR PLYWOOD VENEER DRYERS--ORGANICSa

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

Indirect heated,

heated zones,

softwood

(SCC 3-07-007-62)

Uncontrolled

13466-78-9

75-07-0

67-64-1

107-02-8

80-56-8

71-43-2

127-91-3

50-00-0

138-86-3

67-56-1

108-10-1

1330-20-7

99-83-2

108-95-2

123-38-6

108-88-3

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

1.5f

1.8

 BDL

 BDL

0.040

0.017

0.013

0.0013

0.96

0.00059

0.27

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.014

0.080

0.039

 BDL

0.0015

 BDL

0.00075

 BDL

 BDL

0.017

0.0034

0.0024

 BDL

0.0011

B

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-11

Indirect heated,

cooling section,

softwood

(SCC 3-07-007-63)

Uncontrolled

75-07-0

67-64-1

80-56-8

50-00-0

67-56-1

108-10-1

1330-20-7

95-47-6

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.050

0.054

 BDL

 BDL

 BDL

0.0046

0.0085

 BDL

0.049

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0013

 BDL

0.010

 BDL

0.0054

 BDL

0.0019

0.0014

 BDL

 BDL

0.0062

 BDL

 BDL

 BDL

D

E

D

D

D

D

D

D

D

D

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-12 EMISSION FACTORS 1/2002

Indirect heated,

heated zones,

softwood

(SCC 3-07-007-62)

RTO

75-07-0

67-64-1

80-56-8

71-43-2

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.14

0.17

 BDL

 BDL

 BDL

0.0019

0.0017

 BDL

0.026

0.00040

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0023

 BDL

0.0023

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0050

 BDL

 BDL

 BDL

D

E

D

D

D

E

D

D

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-13

Indirect heated,

heated zones,

hardwood

(SCC 3-07-007-56)

Uncontrolled

75-07-0

67-64-1

50-00-0

67-56-1

108-10-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.23g

0.28

 BDL

 BDL

 BDL

0.0043

0.0040

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0011

 BDL

0.041

 BDL

0.0022

 BDL

 BDL

 BDL

 BDL

 BDL

0.0030

 BDL

 BDL

 BDL

D

E

D

D

D

D

D

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-14 EMISSION FACTORS 1/2002

Indirect heated,

cooling section,

hardwood

(SCC 3-07-007-57)

Uncontrolled

75-07-0

67-64-1

50-00-0

67-56-1

108-10-1

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.62

0.72

 BDL

 BDL

 BDL

0.032

0.047

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0065

 BDL

0.021

 BDL

0.029

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

D

E

D

D

D

D

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-15

Direct natural gasfired, heated zones,

softwood

(SCC 3-07-007-52)

Uncontrolled

75-07-0

67-64-1

107-02-8

80-56-8

71-43-2

127-91-3

50-00-0

138-86-3

74-82-8

67-56-1

78-93-3

108-10-1

1330-20-7

108-95-2

123-38-6

100-42-5

108-88-3

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methane

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

2.1h

2.5

 BDL

 BDL

 BDL

0.062

0.059

0.0090

1.0

0.0057

0.41

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.064j

0.081

0.067k

0.036

0.0019

0.0026

 BDL

0.0039

 BDL

 BDL

 BDL

0.0060

0.0016

0.0015

0.0074

D

E

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-16 EMISSION FACTORS 1/2002

Direct natural gasfired, cooling

section, softwood

(SCC 3-07-007-53)

Uncontrolled

75-07-0

67-64-1

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.038

0.044

 BDL

 BDL

 BDL

0.0034

0.0041

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0015

 BDL

0.0057

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.010

 BDL

 BDL

 BDL

E

E

E

E

E

E

E
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-17

Direct natural gasfired, heated zones,

softwood

(SCC 3-07-007-52)

RCO

75-07-0

67-64-1

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.30

0.36

 BDL

 BDL

 BDL

0.061

0.048

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.038

 BDL

0.0049

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0055

 BDL

 BDL

 BDL

E

E

E

E

E

E

E

Direct wood-fired,

heated zones,

softwood

(SCC 3-07-007-36)

Uncontrolled

50-00-0

THC as carbond

VOC as propanee

Formaldehyde *

0.83m

1.1

0.045n

D

E

D
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-18 EMISSION FACTORS 1/2002

Direct wood-fired,

heated zones,

hardwood

(SCC 3-07-007-34)

Uncontrolled

75-07-0

67-64-1

50-00-0

67-56-1

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.053

0.063

 BDL

 BDL

 BDL

0.0052

0.0045

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.0025

 BDL

0.0095

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

E

E

E

E

E

E
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-19

Direct wood-fired,

cooling section,

hardwood

(SCC 3-07-007-35)

Uncontrolled THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.0037

0.0045

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

E

E
Table 10.5-3 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-20 EMISSION FACTORS 1/2002

Radio frequencyheated redryer,

softwood

(SCC 3-07-007-71)

Uncontrolled

75-07-0

67-64-1

80-56-8

127-91-3

50-00-0

138-86-3

67-56-1

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.23f

0.28

 BDL

 BDL

 BDL

0.0015

0.00089

 BDL

0.17

 BDL

0.056

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

0.00035

0.0040

0.0027

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

 BDL

D

E

D

D

D

D

D

D

D

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick veneer

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. Factors for heating zones and cooling section should be summed when estimating total dryer

emissions. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test method

detection limit; indicates that this pollutant has not been detected in any test runs on this source. 

Reference 17 unless otherwise noted. See Table 10.5-8 for the hardwood and softwood species

commonly used in the production of plywood and other composite wood products. Note: emission

factors in table represent averages of data sets. The data spreadsheets, which may be more

useful for specific applications, are available on EPA’s TTN website at: 

http://www.epa.gov/ttn/chief/.

b Emission control device: RTO = regenerative thermal oxidizer; RCO = regenerative catalytic oxidizer.

c CASRN = Chemical Abstracts Service Registry Number.

d THC as carbon = total hydrocarbon measurements using EPA Method 25A.
Table 10.5-3 (cont.).

1/2002 Wood Products Industry 10.5-21

e VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value of

zero is inserted in the equation for the specified compounds where no emission factor is available, or where

the emission factor is reported only as “BDL”.

f References 16 and 17.

g References 17 and 20.

h References 16, 17, and 18.

j References 17 and 18.

k Reference 18.

m References 16 and 19.

n Reference 19.
10.5-22 EMISSION FACTORS 1/2002

Table 10.5-4. EMISSION FACTORS FOR PLYWOOD PRESSES--PARTICULATE MATTERa

Sourcec

Emission

Control

Device

Filterableb

Condensibled

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Hot press, PF resin,

softwood plywood

(SCC 3-07-007-83)

Uncontrolled 0.12 D ND 0.083 D

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick panel

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. SCC = Source Classification Code. ND = no data available. Reference 16. See Table 10.5-8

for the hardwood and softwood species commonly used in the production of plywood and other

composite wood products. Note: emission factors in table represent averages of data sets. 

The data spreadsheets, which may be more useful for specific applications, are available on

EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent) sampling

train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the cyclone and

filter of an EPA Method 201 or 201A sampling train.

c PF = phenol formaldehyde.

d Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

Table 10.5-5. EMISSION FACTORS FOR PLYWOOD PRESSES--NOx, CO, AND CO2

a

Sourceb

Emission

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hot press, PF resin,

softwood plywood

(SCC 3-07-007-83)

Uncontrolled ND ND ND

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick panel

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. SCC = Source Classification Code. ND = no data available. See Table 10.5-8 for the

hardwood and softwood species commonly used in the production of plywood and other composite

wood products. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s TTN

website at: http://www.epa.gov/ttn/chief/.

b PF = phenol formaldehyde.
1/2002 Wood Products Industry 10.5-23

Table 10.5-6. EMISSION FACTORS FOR PLYWOOD PRESSES--ORGANICSa

Sourceb

Emission

Control Device CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

Hot press, PF resin,

softwood plywood

(SCC 3-07-007-83)

Uncontrolled

75-07-0

67-64-1

80-56-8

127-91-3

50-00-0

138-86-3

67-56-1

78-93-3

108-10-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.21f

0.25

BDL

BDL

BDL

0.0042

0.0065

BDL

0.098

BDL

0.038

BDL

BDL

BDL

BDL

BDL

BDL

0.0019g

0.011

0.14

0.00087

0.00071

BDL

BDL

BDL

BDL

BDL

0.0014

BDL

BDL

BDL

D

E

D

D

D

D

D

D

D

D

D

D
Table 10.5-6 (cont.).

Sourceb

Emission

Control Device CASRNc Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-24 EMISSION FACTORS 1/2002

Hot press, UF resin,

hardwood plywood

(SCC 3-07-007-85)

Uncontrolled

67-64-1

50-00-0

67-56-1

108-10-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.055h

0.047

BDL

BDL

BDL

BDL

0.025

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0047

BDL

0.032

BDL

0.0057

BDL

BDL

BDL

BDL

BDL

0.011

BDL

BDL

BDL

D

E

D

D

D

D

D

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick panel

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test method

detection limit; indicates that this pollutant has not been detected in any test runs on this source. 

Reference 17 unless otherwise noted. See Table 10.5-8 for the hardwood and softwood species

commonly used in the production of plywood and other composite wood products. Note: emission

factors in table represent averages of data sets. The data spreadsheets, which may be more

useful for specific applications, are available on EPA’s TTN website at: 

http://www.epa.gov/ttn/chief/.

b PF = phenol formaldehyde; UF = urea formaldehyde.

c CASRN = Chemical Abstracts Service Registry Number.

d THC as carbon = total hydrocarbon measurements using EPA Method 25A.

e VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.
Table 10.5-6 (cont.).

1/2002 Wood Products Industry 10.5-25

f References 16, 17, and 21.

g References 17 and 21.

h References 17 and 20.
10.5-26 EMISSION FACTORS 1/2002

Table 10.5-7. EMISSION FACTORS FOR PLYWOOD MISCELLANEOUS SOURCES a

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

Log storage

(SCC 3-07-008-95)

Uncontrolled ND PM, THC, VOC ND

Debarking

(SCC 3-07-008-01)

Uncontrolled ND PM, THC, VOC ND

Log bucking (cutting)

(SCC 3-07-008-02)

Uncontrolled ND PM, THC, VOC ND

Veneer cutting

(SCC 3-07-007-25)

Uncontrolled ND PM, THC, VOC ND

Veneer layup and glue

spreading

 (SCC 3-07-007-27)

Uncontrolled ND PM, THC, VOC ND

Plywood cutting

 (SCC 3-07-007-10)

Uncontrolled ND PM, THC, VOC ND

Plywood finishing

 (SCC 3-07-007-02)

Uncontrolled ND PM, THC, VOC ND
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-27

Hardwood plywood

combined dust baghouse

(includes trim saw,

composer, core saw, dry

hog, hammermill, and

sander)e

(SCC 3-07-007-88)

Use with caution!

Uncontrolled

67-64-1

67-56-1

PM

THC as carbonf

VOC as propaneg

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

0.019

0.014

BDL

BDL

BDL

BDL

0.0089

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0029

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

U

U

U

U
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-28 EMISSION FACTORS 1/2002

Softwood plywood, log

steaming vat

(SCC 3-07-007-89)

Use with caution!

Uncontrolled

75-07-0

67-64-1

80-56-8

127-91-3

67-56-1

PM

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

BDL

BDL

BDL

0.0047

0.0030

BDL

0.056

BDL

0.0064

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0073

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

U

U

U

U

U
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-29

Softwood plywood, dry

veneer trim chipper

(trimmed veneer from

layup line)

(SCC 3-07-007-90)

Use with caution!

Uncontrolled

75-07-0

67-64-1

80-56-8

50-00-0

67-56-1

108-95-2

PM

THC as carbonf

VOC as propaneg

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

0.059

0.072

BDL

BDL

BDL

0.00081

0.00082

BDL

0.032

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.00034

BDL

0.0087

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0019

BDL

BDL

BDL

U

U

U

U

U

U

U

U
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-30 EMISSION FACTORS 1/2002

Softwood plywood, dry

plywood trim chipper

(trim from panel saws)

(SCC 3-07-007-91)

Use with caution!

Uncontrolled

80-56-8

67-56-1

PM

THC as carbonf

VOC as propaneg

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

0.056

0.068

BDL

BDL

BDL

BDL

BDL

BDL

0.036

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0078

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

U 

U 

U

U
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

1/2002 Wood Products Industry 10.5-31

Softwood plywood

sander (includes sanders

and specialty saw)h

(SCC 3-07-007-92)

Use with caution!

Uncontrolled

75-07-0

67-64-1

80-56-8

50-00-0

67-56-1

PM

THC as carbonf

VOC as propaneg

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

0.15

0.18

BDL

BDL

BDL

0.0028

0.0047

BDL

0.023

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0018

BDL

0.012

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

U

U

U

U

U

U

U
Table 10.5-7 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.5-32 EMISSION FACTORS 1/2002

Softwood plywood saws

(includes 3 saws, hog,

and sander)j

(SCC 3-07-007-93)

Use with caution!

Uncontrolled

75-07-0

67-64-1

80-56-8

50-00-0

67-56-1

PM

THC as carbonf

VOC as propaneg

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

ND

0.072

0.086

BDL

BDL

BDL

0.00092

0.0019

BDL

0.027

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.00034

BDL

0.012

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

U

U

U

U

U

U

U

a Emission factor units are pounds of pollutant per thousand square feet of 3/8-inch thick panel

(lb/MSF 3/8). One lb/MSF 3/8 = 0.5 kg/m3. Factors represent uncontrolled emissions unless otherwise

noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test method

detection limit; indicates that this pollutant has not been detected in any test runs on this source. ND =

no data available. U = emission factor unrated. These emission factors should be used with caution;

the ducting arrangements of these miscellaneous sources varies from mill to mill, therefore, these

emission factors may not provide accurate estimates of emissions from other mills. Reference 17. See

Table 10.5-8 for the hardwood and softwood species commonly used in the production of plywood and

other composite wood products. Note: emission factors in table represent averages of data

sets. The data spreadsheets, which may be more useful for specific applications, are available

on EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b SPW = softwood plywood; HPW = hardwood plywood.

c Emission control devices (baghouses) are considered no control for organic pollutants.

d CASRN = Chemical Abstracts Service Registry Number.
Table 10.5-7 (cont.).

1/2002 Wood Products Industry 10.5-33

e A composer is a device used for gluing veneers along the edge to form larger sheets of veneer; a core

saw is used to cut core plies of veneer separately from decorative face veneers; a dry hog is used to

reduce the size of wood residue by slicing or chopping; a hammermill is used to pulverize wood residue

into small particles.

f THC as carbon = total hydrocarbon measurements using EPA Method 25A.

g VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

h A specialty saw is used for cutting and grooving the edges of plywood panels for tongue and groove

joints.

j A hog is used to reduce the size of wood residue by slicing or chopping.
10.5-34 EMISSION FACTORS 1/2002

Table 10.5-8. WOOD SPECIES COMMONLY USED IN 

COMPOSITE WOOD PRODUCTS MANUFACTURING a

Wood product AP-42 section Hardwood species Softwood species

Plywood 10.5 Oak, cherry, poplar, maple, larch Firs, pines

Oriented strandboard 10.6-1 Aspen Pines, firs, spruce

Particleboard 10.6-2 Aspen, oak Pines, firs

Medium density fiberboard 10.6-3 Gum, alder, hickory Pines, firs

Hardboard/fiberboard 10.6-4 Aspen, birch, beech, oak, maple Pines

Engineered wood products 10.9 Aspen, birch, poplar Pines, firs, hemlock

a Reference 15.
1/2002 Wood Products Industry 10.5-35

References For Section 10.5

1. C. B. Hemming, Plywood, Kirk-Othmer Encyclopedia Of Chemical Technology, Second

Edition, Volume 15, John Wiley & Sons, Inc., New York, NY, 1968, pp. 896 - 907.

2. F. L. Monroe, et al., Investigation Of Emissions From Plywood Veneer Dryers, Washington

State University, Pullman, WA, February 1972.

3. T. Baumeister, ed., Plywood, Standard Handbook For Mechanical Engineers, Seventh

Edition, McGraw-Hill, New York, NY, 1967, pp. 6-162 - 6-169.

4. Written communication from John Pinkerton, National Council of the Paper Industry for Air and

Stream Improvement, Inc., to Dallas Safriet, U. S. Environmental Protection Agency, Research

Triangle Park, NC, April 13, 1993.

5. A. Mick, and D. McCargar, Air Pollution Problems In Plywood, Particleboard, And

Hardboard Mills In The Mid-Willamette Valley, Mid-Willamette Valley Air Pollution Authority,

Salem, OR, March 24, 1969.

6. Controlled And Uncontrolled Emission Rates And Applicable Limitations For Eighty

Processes, Second Printing, EPA-340/1-78-004, U. S. Environmental Protection Agency,

Research Triangle Park, NC, April 1978, pp. X-1 - X-6.

7. J. A. Danielson, ed., Air Pollution Engineering Manual, AP-40, Second Edition,

U. S. Environmental Protection Agency, Research Triangle Park, NC, May 1973, pp. 372 - 374.

8. Assessment Of Fugitive Particulate Emission Factors For Industrial Processes,

EPA-450/3-78-107, U. S. Environmental Protection Agency, Research Triangle Park, NC,

September 1978.

9. C. T. Van Decar, Plywood Veneer Dryer Control Device, Journal Of The Air Pollution

Control Association, 22:968, December 1972.

10. Alternative Control Technology Document--PM-10 Emissions From The Wood Products

Industry: Plywood Manufacturing, Draft, U. S. Environmental Protection Agency, Research

Triangle Park, NC, September 1992.

11. Written communication from John Pinkerton, National Council of the Paper Industry for Air and

Stream Improvement, Inc., to Dallas Safriet, U. S. Environmental Protection Agency, Research

Triangle Park, NC, June 8, 1993.

12. Written communication and attachments from T. A. Crabtree, Smith Engineering Company,

Broomall, PA, to P. E. Lassiter, U. S. Environmental Protection Agency, Research Triangle Park,

NC, July 26, 1996.

13. Technical Memorandum, Minutes of the October 12-13, 1993 BACT Technologies Workshop,

Raleigh, NC, sponsored by the American Forest and Paper Association, K. D. Bullock, Midwest

Research Institute, Cary, NC, October 1993.
10.5-36 EMISSION FACTORS 1/2002

14. A. E. Cavadeas, RTO Experience In The Wood Products Industry, Presented at Environmental

Challenges: What’s New in the Wood Products Industry?, Workshop sponsored by the American

Forest and Paper Association, Research Triangle Park, NC, February 4-5, 1997.

15. Emission Factor Documentation For AP-42 Chapter 10, Wood Products Industry, prepared

for the U. S. Environmental Protection Agency, OAQPS/EFIG, by Midwest Research Institute,

Cary, NC, July 2003.

16. Oriented Strandboard And Plywood Air Emission Databases, Technical Bulletin No. 694,

National Council of the Paper Industry for Air and Stream Improvement, Inc., New York, NY,

April 1995.

17. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part

I - Plywood, Technical Bulletin No. 768, National Council of the Paper Industry for Air and

Stream Improvement, Inc., Research Triangle Park, NC, 1999.

18. Engineering Evaluation Test Report, Formaldehyde, Total Hydrocarbons, And Methane

Emissions From Four Process Stacks, Willamette Industries, Inc., Emerson, Louisiana, Test

Dates April 23-24, 1998, prepared for Willamette Industries, Inc., by DEECO, Inc., Project

No. 1559, June 7, 1998.

19. Emissions Test Report, Willamette Industries, Springfield, Oregon, Veneer Dryer #1 And

Veneer Dryer #2, Test Dates June 1-2, 1998, prepared for Willamette Industries, by BWR

Associates, Inc., Project No. 98-092D, 1998.

20. Source Test Report–Woodtech, Inc., Bluefield, Virginia, prepared for Woodtech, Inc., by

Environmental Quality Management, Inc., and Pacific Environmental Services, January 1992. 

21. Press Room Vent Emissions Sampling, Willamette Industries, Inc., Emerson, Louisiana, Test

Dates February 8-9, 1995, prepared for Willamette Industries, Inc., by Armstrong

Environmental, Inc., Project W-1653-95, February 20, 1995.

22. Written communication from Charles Simon, Precision Analytical Laboratories, Incorporated, to

Dallas Safriet, U. S. Environmental Protection Agency, Research Triangle Park, NC, July 5,

2001.
6/2002 Wood Products Industry 10.6.2-1

10.6.2 Particleboard Manufacturing

10.6.2.1 General1,2 -

Particleboard is defined as a panel product manufactured from lignocellulosic materials,

primarily in the form of discrete particles, combined with a synthetic resin or other suitable binder and

bonded together under heat and pressure. The primary difference between particleboard and other

reconstituted wood products, such as waferboard, oriented strandboard, medium density fiberboard, and

hardboard, is the material or particles used in its production. The major types of particles used to

manufacture particleboard include wood shavings, flakes, wafers, chips, sawdust, strands, slivers, and

wood wool. The term particleboard sometimes is used generically to include waferboard and oriented

strandboard, which are manufactured primarily with wood flakes and wafers. However, for the purposes

of this report, particleboard pertains only to panels manufactured from a mixture of wood particles or

otherwise from wood particles other than wafers and flakes. Particleboard manufacturing falls under

Standard Industrial Classification (SIC) Code 2493, reconstituted wood products, which includes

hardboard, insulation board, medium density fiberboard, waferboard and oriented strandboard in addition

to particleboard. The six-digit Source Classification Code (SCC) for particleboard manufacturing is 3-

07-006. 

10.6.2.2 Process Description1,2 -

Particleboard is produced in densities ranging from around 590 kilograms per cubic meter

(kg/m3) (37 pounds per cubic foot [lb/ft3]) to greater than 800 kg/m3 (50 lb/ft3). Most particleboard is

formed into panels. However, molded particleboard products such as furniture parts, door skins, or

molded pallets are also produced.

Although some single-layer particleboard is produced, particleboard generally is manufactured in

three or five layers. The outer layers are referred to as the surface or face layers, and the inner layers are

termed the core layers. Face material generally is finer than core material. By altering the relative

properties of the face and core layers, the bending strength and stiffness of the board can be increased.

The general steps used to produce particleboard include raw material procurement or generation,

classifying by size, drying, blending with resin and sometimes wax, forming the resinated material into a

mat, hot pressing, and finishing. Figure 10.6.2-1 presents a process flow diagram for a typical

particleboard plant.

The furnish or raw material for particleboard normally consists of wood particles, primarily

wood chips, sawdust, and planer shavings. This material may be shipped to the facility or generated

onsite and stored until needed. In mills where chips are generated onsite, logs are debarked, sawn to

proper length, and chipped. After shipping to the site or generation onsite, the furnish may be further

reduced in size by means of hammermills, flakers, or refiners. After milling, the material is either

screened using vibrating or gyratory screens, or the particles are air-classified. The purpose of this step

is to remove the fines and to separate the core material from the surface material. The screened or

classified material then is transported to storage bins.

From the storage bins, the core and surface material are conveyed to dryers. Rotary dryers are

the most commonly used dryer type in the particleboard industry. Both single and triple-pass dryers are

used. In addition, some facilities use tube dryers to dry the furnish. Wood-fired dryers are used at most

facilities. However, gas- and oil-fired dryers also are used. The moisture content of the particles

entering the dryers may be as high as 50 percent on a wet basis. Drying reduces the moisture content to

2 to 8 percent. Dryer inlet temperatures may be as high as 871°C (1600°F) if the furnish is wet; for dry

furnish, inlet temperatures generally are no higher than 260°C (500°F). Dryers with an inlet furnish
10.6.2-2 EMISSION FACTORS 2/2002

moisture content of greater than 50 percent on a dry basis are labeled “green” dryers. A predryer may be

used for initial drying of relatively wet furnish. Following predrying, the drying process is completed in

a final dryer (which may be either a rotary dryer or a tube dryer). The dryer inlet temperature is adjusted

based on the desired furnish moisture content at the dryer outlet. Core dryers generally operate at higher

temperatures than surface dryers due to differences in core and surface particle characteristics and

because a lower moisture content is more desirable for core material. 

After drying, the particles pass through a primary cyclone for product recovery and then are 

transferred to holding bins. Face material sometimes is screened to remove the fines, which tend to

absorb too much of the resin, prior to storage in the holding bins. From the holding bins, the core and

surface materials are transferred to blenders, in which the particles are mixed with resin, wax, and other

additives by means of spray nozzles, tubes, or atomizers. Urea-formaldehyde is the resin most commonly

used for particleboard manufacture. However, phenol-formaldehyde resin may be used for particleboard

produced for exterior applications.

Waxes are added to impart water resistance, increase the stability of the finished product under

wet conditions, and to reduce the tendency for equipment plugging. For furnishes that are low in acidity,

catalysts also may be blended with the particles to accelerate the resin cure and to reduce the press time.

Formaldehyde scavengers also may be added in the blending step to reduce formaldehyde emissions from

the process.

Blenders generally are designed to discharge the resinated particles into a plenum over a belt

conveyor that feeds the blended material to the forming machine, which deposits the resinated material in

the form of a continuous mat. Formers use air to convey the material, which is dropped or thrown into an

air chamber above a moving caul, belt, or screen and floats down into position. To produce multilayer

particleboard, several forming heads can be used in series, or air currents can produce a gradation of

particle sizes from face to core. As it leaves the former, the mat may be prepressed prior to trimming and

pressing. The mats then are cut into desired lengths and conveyed to the press. The press applies heat

and pressure to activate the resin and bond the fibers into a solid panel. Although some single-opening

presses are used, most domestic particleboard plants are equipped with multi-opening batch presses. 

Total press time is generally 2.5 minutes (min) for single-opening presses and up to 6 min for multiopening presses. Continuous presses may also be used to produce particleboard. Presses generally are

heated using steam generated by an onsite boiler that burns wood residue. However, hot oil and hot

water also are used to heat the press. The operating temperature for particleboard presses generally

ranges from 149° to 182°C (300° to 360°F).

The presses used to manufacture molded particleboard products are not platen presses, but are

press molds equipped with a heated die that shapes the resinated wood particles into the finished product. 

Press temperatures can range from 132° to 288°C (270° to 550°F). Press temperature and time vary

according to the molded product being produced.

After pressing, the boards generally are cooled prior to stacking. The particleboard panels then

are sanded and trimmed to final dimensions, any other finishing operations (including laminate or veneer

application) are done, and the finished product is packaged for shipment.
6/2002 Wood Products Industry 10.6.2-3

Milling

(SCC 3-07-006-

64)

Core

Material

Storage

Cooling

(SCC 3-07-006-

61)

Sanding

(SCC 3-07-006-

65)

Trimming

Other

Finishing

Operations

Drying

(SCC 3-07-006-

02 to -40)

Drying

(SCC 3-07-006-

02 to -40)

Cyclone

Screening

Surface

Material

Storage

Cyclone

Core

Material

Storage

Blending Forming Blending Resin, wax

other additives

Prepressing Trimming

Heat, pressure

Pressing

(SCC 3-07-006-

51, -55)

Steam/hot oil/hot water

Resin, wax,

other additives

Direct/Indirect

Heat

Screening/

Classifying

Surface

Material

Storage

PROCESS FLOW

OPTIONAL PROCESS

ON-SITE PARTICLE GENERATION:

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC 3-07-008-02)

OFFSITE PARTICLE

GENERATION

Figure 10.6.2-1. Process flow diagram for particleboard manufacturing.
10.6.2-4 EMISSION FACTORS 2/2002

10.6.2.3 Emissions And Controls1-35 -

The primary emission sources at particleboard mills are particle dryers and hot press vents. 

Other emission sources may include boilers, particle generation, blending, forming, board cooling, and

finishing operations such as sanding, trimming, and laminate or veneer application. Other potential

emissions sources ancillary to the manufacturing process may include wood chip storage piles and bins

(including wood fuel), chip handling systems, and resin storage and handling systems.

Although most particleboard mills have chips delivered from offsite locations, in mills where

chips are generated onsite, operations such as log debarking and sawing, in addition to particle mills,

screens, and classifiers generate particulate matter (PM) and PM less than 10 micrometers in

aerodynamic diameter (PM-10) emissions in the form of sawdust and wood particles. In addition, these

processes may be sources of PM less than 2.5 micrometers in aerodynamic diameter (PM-2.5) emissions.

Emissions from dryers that are exhausted from the primary recovery cyclone include wood dust

and other solid PM, volatile organic compounds (VOCs), condensible PM, and products of combustion

such as carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxides (NOx), if direct-fired units are

used. The condensible PM and a portion of the VOCs leave the dryer stack as vapor but condense at

normal atmospheric temperatures to form liquid particles or mist that creates a visible blue haze. Both

the VOCs and condensible PM are primarily compounds evaporated from the wood, with a minor

constituent being combustion products. Quantities emitted are dependent on wood species, dryer

temperature, fuel used, and other factors including season of the year, time between logging and

processing, and chip storage time.

Emissions from board hot presses are dependent on the type and amount of resin used to bind the

wood fibers together, as well as wood species, wood moisture content, wax and catalyst application rates,

and press conditions. When the press opens, vapors that may include resin ingredients such as

formaldehyde and other VOCs are released. The rate at which formaldehyde is emitted during pressing

and board cooling operations is a function of the amount of excess formaldehyde in the resin, board

thickness, press temperature, press cycle time, and catalyst application rates.

Emissions from finishing operations for particleboard are dependent on the type of products

being finished. For most particleboard products, finishing involves trimming to size and sanding. Some

products may require application of laminate surfaces or veneers with adhesives. Trimming and sanding

operations are sources of PM and PM-10 emissions. In addition, these processes may be sources of PM

less than 2.5 micrometers in aerodynamic diameter (PM-2.5) emissions. No data specific to

particleboard trimming and sawing are available. However, emissions factors for plywood or medium

density fiberboard (MDF) sawing operations may provide an order of magnitude estimate for similar

particleboard sawing and trimming operations.

In particleboard mills where particles are generated onsite, PM, PM-10, and PM-2.5 emissions

from log debarking, sawing, and grinding operations can be controlled through capture in an exhaust

system connected to a sized cyclone and/or fabric filter collection system. Emissions of PM, PM-10, and

PM-2.5 from sanding and final trimming operations can be controlled using similar methods. These

wood dust capture and collection systems are used not only to control atmospheric emissions, but also to

recover the dust as a by-product fuel for a boiler or dryer. 

Methods of controlling PM emissions from the particleboard sources include multiclones,

absorption systems (wet scrubbers), fabric filters, sand filter scrubbers, electrified filter beds (EFBs), wet

electrostatic precipitators (WESPs), and oxidation systems (discussed below). The sand filter scrubber

incorporates a wet scrubbing section followed by a wet-sand filter and mist eliminator. The EFB uses
6/2002 Wood Products Industry 10.6.2-5

electrostatic forces to attract pollutants to an electrically charged gravel bed. The WESP uses

electrostatic forces to attract pollutants to either a charged metal plate or a charged metal tube. The

collecting surfaces are continually rinsed with water to wash away the pollutants. Wet PM control

systems such as wet scrubbers and WESP’s may achieve short-term reductions in emissions of some

water-soluble organic compounds (such as formaldehyde). However, the ability of these wet systems to

absorb water-soluble compounds diminishes as the recirculating scrubbing liquid becomes saturated with

these compounds.

A VOC control technology commonly used in the wood products industry for controlling both

dryer and press exhaust gases is regenerative thermal oxidation. Thermal oxidizers destroy VOCs and

condensible organics by burning them at high temperatures. Thermal oxidizers also reduce CO emissions

in direct-fired dryer exhausts by oxidizing the CO in the exhaust to CO2 (a product of complete

combustion). Regenerative thermal oxidizers (RTOs) are designed to preheat the inlet emission stream

with heat recovered from the incineration exhaust gases. Up to 98 percent heat recovery is possible,

although 95 percent is typically specified. Gases entering an RTO are heated by passing through preheated beds packed with a ceramic media. A gas burner brings the preheated emissions up to an

incineration temperature between 788° and 871°C (1450° and 1600°F) in a combustion chamber with

sufficient gas residence time to complete the combustion. Combustion gases then pass through a cooled

ceramic bed where heat is extracted. By reversing the flow through the beds, the heat transferred from

the combustion exhaust air preheats the gases to be treated, thereby reducing auxiliary fuel requirements.

Biofiltration systems are also used effectively for control of a variety of pollutants including 

organic compounds, NOx, CO, and PM from press exhaust streams. Biofiltration uses microorganisms

immobilized in a biofilm layer on a porous packing such as bark, wood chips, or synthetic media. 

Typical biofilter design consists of a three- to six-foot deep bed of media suspended over an air

distribution plenum. Exhaust gases entering the plenum are evenly distributed through the moist biofilter

media. As the contaminated vapor stream passes through the biofilter media, pollutants are transferred

from the vapor to the biofilm and, through microbiological degradation, are converted to CO2, water, and

salts. The microorganisms cannot easily attack pollutants in the gas phase; therefore, less water soluble

compounds (such as pinenes) are generally more difficult to control using a biofilter than are the more

water-soluble compounds (such as formaldehyde).

Fugitive PM emissions from road dust and uncovered bark and dust storage piles may be

controlled in a number of different ways. Some of these methods include enclosure, wet suppression

systems, and chemical stabilization.

Calculating PM-10 emissions from wood products industry emission sources is problematic due

to the relationship between PM-10 (or PM) emissions and VOC emissions from these processes. 

Because the Method 201A train (PM-10) operates with an in-stack cyclone and filter, organic materials

that are volatile at stack gas temperatures but that are condensed at back half impinger temperatures

(-20°C [-68°F]) are collected as condensible PM-10. However, these materials will also be measured as

VOC via Methods 25 and 25A, which operate with a heated or an in-stack filter. Hence, if PM-10 is

calculated as the sum of filterable and condensible material, some pollutants will be measured as both

PM-10 and VOC emissions. However, if only filterable material is considered to be PM-10, the PM-10

emission factors will be highly dependent on stack gas temperature. In this AP-42 section, PM-10 is

reported as front half catch only (Method 201A results only; not including Method 202 results). 

However, condensible PM results are also reported, and these results can be combined with the PM-10

results as appropriate for a specific application. Measured VOC emissions may be affected by the

sampling method and by the quantity of formaldehyde and other aldehydes and ketones in the exhaust;

formaldehyde is not quantified using Method 25A. Other low molecular weight oxygenated compounds
10.6.2-6 EMISSION FACTORS 2/2002

have reduced responses to Method 25A. Therefore, when VOC emissions are measured using

Method 25A, the emission rates will be biased low if low molecular weight oxygenated compounds are

present in significant concentrations in the exhaust stream. A more extensive discussion of these

sampling and analysis issues is provided in the Background Report for this section.

Guidance from EPA’s Emission Factor and Inventory Group (EFIG) indicates that when it is

possible, VOC emission factors should be reported in terms of the actual weight of the emitted

compound. However, when an actual molecular weight (MW) of the emitted stream is not feasible (as is

the case with the mixed streams emitted from wood products industry sources), the VOC should be

reported using an assumed MW of 44, and reported “as propane.” Each VOC-as-propane emission factor

is estimated by first converting the THC from a carbon basis to a propane basis. Propane (MW = 44)

includes 3 carbon atoms (total MW of 36) and 8 hydrogen atoms (total MW of 8). Every 36 pounds of

carbon measured corresponds to 44 pounds of propane. The ratio of the MW of propane to the MW of

carbon in propane is 44/36, or 1.22. The conversion is expressed by the following equation:

THC as pounds carbon × 44 pounds propane

36 pounds carbon = THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

After the THC emission factor has been converted from a carbon to a propane basis, the

formaldehyde emission factor is added (where available), then the available emission factors for

non-VOC compounds, including acetone, methane, and methylene chloride, are subtracted. This

procedure is expressed simply by the following equation:

VOC as propane = (1.22 × THC as carbon) + formaldehyde - (acetone + methane + methylene chloride)

In cases where no emission factor is available (or the emission factor is reported only as below the test

method detection limit, or “BDL”) for one or more of the compounds used to estimate the VOC-aspropane value, adjustments to the converted THC value are made only for those compounds for which

emission factors are available. That is, a value of zero is inserted in the above equation for the specified

compounds where no emission factor is available, or where the emission factor is reported only as BDL. 

For example, if no methane emission factor is available, the THC-as-carbon emission factor is converted

to THC-as-propane, formaldehyde is added, and only acetone and methylene chloride are subtracted.

Table 10.6.2-1 presents emission factors for dryer emissions of PM, including filterable PM,

filterable PM-10, and condensible PM. Table 10.6.2-2 presents emissions factors for dryer emissions of

NOx, CO, and CO2. Table 10.6.2-3 presents emission factors for dryer emissions of organic compounds,

some of which are listed as HAPs under section 112(b) of the Clean Air Act. The emission factors for

dryer emissions are presented in units of pounds of pollutant per oven-dried ton of wood material out of

the dryer (lb/ODT). Table 10.6.2-4 presents emission factors for press and board cooler emissions of

PM, including filterable PM, filterable PM-10, and condensible PM. Table 10.6.2-5 presents emission

factors for press and board cooler emissions of NOx and CO. Table 10.6.2-6 presents emission factors

for press and board cooler emissions of organic compounds, some of which are listed HAPs. The units

for the press and board cooler emission factors are pounds of pollutant per thousand square feet of 3/4-

inch thick panel produced (lb/MSF 3/4). Table 10.6.2-7 presents emission factors for miscellaneous

sources of organic compounds. Some of the compounds also are listed HAPs.

To the extent possible, separate emission factors for particleboard dryers are presented in

Tables 10.6.2-1 to -3 for hardwoods and softwoods. Hardwoods generally correspond to deciduous

species. For particleboard, plywood, and other composite wood products, commonly used hardwoods
6/2002 Wood Products Industry 10.6.2-7

include aspen, oak, poplar, maple, cherry, alder, hickory, gum, beech, birch, and basswood. The

emission factors for hardwood particleboard dryers presented in this section are based largely on the

drying of aspen furnish. Oak also is used often for making particleboard. Softwoods generally

correspond to coniferous species. For particleboard, plywood, and other composite wood products,

commonly used softwoods include pines, firs, and spruce. Pines and firs are the most commonly used

softwood species for particleboard manufacturing.

Emission factors for every possible mix of hardwood and softwood species cannot be reported in

this section. Emission factors for specific mixes of wood species may be calculated by combining

emission factors for individual wood species in the ratio specific to a given application, as emission data

for those species become available. For example, a THC as carbon emission factor for a direct woodfired rotary dryer processing 60 percent softwood and 40 percent hardwood may be calculated using the

THC as carbon emission factors for softwood (1.0 lb/ODT) and hardwood (0.20 lb/ODT), and the ratio

of 60 percent to 40 percent. The resultant emission factor, rounded to two significant figures, would be

0.68 lb/ODT.
10.6.2-8 EMISSION FACTORS 2/2002

Table 10.6.2-1. EMISSION FACTORS FOR PARTICLEBOARD DRYERS--

PARTICULATE MATTERa

Source

Emission

Control

Devicec

Filterableb

Condensibled

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Rotary dryer, direct

wood-fired,

hardwood

(SCC 3-07-006-10)

Uncontrolled/

MCLO

SCBR

EFB

033.3e

0

00.93e

00.19e

D

D

D

ND

ND

ND

0.21e

0.024e

NA

D

D

Rotary dryer, direct

wood-fired,

softwood

(SCC 3-07-006-07)

Uncontrolled

MCLO

03.4e

00.93f

D

D

0.69e

ND

D 0.20e

ND

D

Rotary dryer, direct

wood-fired, mixed

species (35-60%

softwood, 40-65%

hardwood)

(SCC 3-07-006-08)

Uncontrolled

EFB

02.2g

00.28h

D

D

ND

ND

0.48g

 NA

D

Rotary dryer, green,

direct wood-fired

(inlet moisture

content >50%, dry

basis), softwood

(SCC 3-07-006-25)

Uncontrolled/

MCLO

BH

EFB

EFB/BH

02.2h

01.4h

01.5e

00.20h

D

E

E

E

ND

ND

0.64e

ND

E

1.1h

NA

NA

NA

D

Rotary dryer, green,

direct wood-fired

(inlet moisture

content >50%, dry

basis), mixed

species (40-60%

softwood, 40-60%

hardwood)

(SCC 3-07-006-26)

Uncontrolled

MCLO

BH

EFB

EFB/BH

 ND

2.0e

01.3h

00.27e

00.15j

E

E

E

E

ND

ND

ND

0.11e

ND

D

0.62k

NA

NA

NA

NA

D

Rotary dryer, direct

natural gas-fired,

hardwood

(SCC 3-07-006-32)

Uncontrolled

MCLO

EFB

ND

2.2e

00.31n

E

E

ND

ND

0.15m

NA

ND

D

Rotary dryer, direct

natural gas-fired,

softwood

(SCC 3-07-006-30)

Uncontrolled/

MCLO

00.42pD ND 0.12qD

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. NA = Not applicable. 

See Table 10.6.2-8 for the hardwood and softwood species commonly used in the production of

particleboard and other composite wood products. Note: emission factors in table represent

averages of data sets. The data spreadsheets, which may be more useful for specific applications,
Table 10.6.2-1 (cont.).

6/2002 Wood Products Industry 10.6.2-9

are available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b

Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c

Emission control device: MCLO = multiclone; SCBR = wet scrubber; EFB = electrified filter bed; BH

= baghouse (fabric filter).

d Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202); multiclones, EFB’s, and baghouses are not expected to control condensible PM; condensible PM

emissions measured at the outlets of those control devices are considered to be uncontrolled.

e Reference 7.

f References 8, 9, and 10.

g References 7, 11, 12, and 13.

h References 7 and 14.

j Reference 14.

k Reference 7, 11, and 14.

m Reference 7, 15, and 16.

n Reference 16.

p Reference 8, 17, and 18.

q Reference 17 and 18.
10.6.2-10 EMISSION FACTORS 2/2002

Table 10.6.2-2. EMISSION FACTORS FOR PARTICLEBOARD DRYERS--NOx, CO, AND CO2

a

Sourceb

Emission

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Rotary dryer, direct

wood-fired,

hardwood

(SCC 3-07-006-10)

Uncontrolled 0.92cD 5.7cD ND

Rotary dryer, direct

wood-fired,

softwood

(SCC 3-07-006-07)

Uncontrolled 0.58dD 0.68eC ND

Rotary dryer, direct

wood-fired, mixed

species (35-60%

softwood, 40-65%

hardwood)

(SCC 3-07-006-08)

Uncontrolled 1.8fD 0.59cD 538gD

Rotary dryer, green,

direct wood-fired

(inlet moisture

content >50%, dry

basis), softwood

(SCC 3-07-006-25)

Uncontrolled 2.7hD 3.5hD 573jD

Rotary dryer, green,

direct wood-fired

(inlet moisture

content >50%, dry

basis), mixed

species (40-60%

softwood, 40-60%

hardwood)

(SCC 3-07-006-26)

Uncontrolled 1.4cE 0.77kD ND

Rotary dryer, direct

natural gas-fired,

hardwood

(SCC 3-07-006-32)

Uncontrolled 0.024mE 1.2mE 311nE

Rotary dryer, green,

direct natural gasfired (inlet moisture

content >50%, dry

basis), softwood

(SCC 3-07-006-31)

Uncontrolled ND ND 237pD

Rotary dryer,

indirect heated with

auxiliary natural

gas, softwood

(SCC 3-07-006-35)

Uncontrolled 0.31cD 0.12cD 38.2qD
Table 10.6.2-2 (cont.).

Sourceb

Emission

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

6/2002 Wood Products Industry 10.6.2-11

Tube dryer, direct

wood-fired,

blowline blend, UF

resin, hardwood

(SCC 3-07-006-40)

Uncontrolled ND ND 447rE

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. See Table 10.6.2-8 for

the hardwood and softwood species commonly used in the production of particleboard and other

composite wood products. Note: emission factors in table represent averages of data sets. The

data spreadsheets, which may be more useful for specific applications, are available on EPA’s

Technology Transfer Network (TTN) website at: http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c Reference 7.

d References 7, 9, and 10.

e References 7, 9, 10, and 19.

f References 7, 12, and 13.

g References 11, 12, 13, and 14.

h References 7, 20, and 21.

j References 14, 20, and 21.

k References 7 and 19.

m Reference 15.

n Reference 22.

p References 21 and 23.

q Reference 24.

r Reference 25.
10.6.2-12 EMISSION FACTORS 2/2002

Table 10.6.2-3. EMISSION FACTORS FOR PARTICLEBOARD DRYERS--ORGANICSa

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

EMISSION

FACTOR

RATING

Rotary dryer, direct

wood-fired,

hardwood

(SCC 3-07-006-10)

Uncontrolled THC as carbond

VOC as propanee

0.20f

0.24

D

E

Rotary dryer, direct

wood-fired, softwood

(SCC 3-07-006-07)

Uncontrolled

71-55-6

95-63-6

5779-94-2

13466-78-9

75-07-0

67-64-1

98-86-2

107-02-8

80-56-8

100-52-7

71-43-2

127-91-3

92-52-4

117-81-7

74-83-9

123-72-8

85-68-7

75-15-0

56-23-5

74-87-3

98-82-8

84-74-2

75-18-3

74-84-0

100-41-4

50-00-0

66-25-1

123-31-9

590-86-3

138-86-3

1330-20-7

620-23-5

64-82-8

67-56-1

78-93-3

108-10-1

75-09-2

110-54-3

95-47-6

THC as carbond

VOC as propanee

1,1,1-Trichloroethane *

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

1,2,4-Trimethyl benzene

2,5-Dimethyl benzaldehyde

3-Carene

Acetaldehyde *

Acetone

Acetophenone

Acrolein *

Alpha-pinene

Benzaldehyde

Benzene *

Beta-pinene

Biphenyl *

Bis-(2-ethylhexyl phthalate)

Bromomethane *

Butylaldehyde

Butylbenzyl phthalate

Camphene

Carbon disulfide *

Carbon tetrachloride *

Chloroethane *

Chloroethene *

Chloromethane *

Cis-1,2-dichloroethylene

Cumene *

Di-N-butyl phthalate

Dimethyl sulfide

Ethane

Ethyl benzene *

Formaldehyde *

Hexaldehyde

Hydroquinone

Isovaleraldehyde

Limonene

m-, p-Xylene *

m-Tolualdehyde

Methane

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

n-Hexane*

o-Xylene *

1.0g

0.90

0.000012f

BDL

BDL

0.000090f

0.000033f,y

0.076

0.013

0.084h

0.000064f

0.0045

0.39

0.0026f,y

0.00099h

0.12

0.000039f

0.00032f

0.000028f

0.0031f,y

0.000014f

BDL

0.000018f

0.000012f

BDL

BDL

0.00011f

BDL

0.000069f

0.000023f

0.000014f

0.015j

0.0000038f

0.025k

0.016f,y

0.000060f

0.00052f,y

0.034

0.00055h

0.00045f,y

0.26j

0.014m

0.0049h

0.0024h

0.00063h

0.000026f

0.000014f

C

D

D

D

E

D

D

D

D

D

D

E

D

D

D

D

D

E

E

D

D

D

D

D

E

D

E

C

E

E

E

D

D

E

D

D

D

D

D

E

D
Table 10.6.2-3 (cont.).

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

EMISSION

FACTOR

RATING

6/2002 Wood Products Industry 10.6.2-13

Rotary dryer, direct

wood-fired, softwood

(SCC 3-07-006-07)

(cont.)

108-95-2

123-38-6

100-42-5

108-88-3

110-62-3

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

BDL

BDL

0.0066

0.0032

0.00012f

0.0021h

0.0016f,y

D

D

E

D

E

Rotary dryer, direct

wood-fired, mixed

species (35-60%

softwood, 40-65%

hardwood)

(SCC 3-07-006-08)

Uncontrolled THC as carbond

VOC as propanee

0.048f

0.059

E

E

Rotary dryer, green,

direct wood-fired,

softwood (inlet

moisture content

>50%, dry basis)

(SCC 3-07-006-25)

Uncontrolled

5779-94-2

13466-78-9

80-56-8

8006-64-2

75-07-0

67-64-1

107-02-8

127-91-3

100-52-7

71-43-2

123-72-8

79-92-5

67-66-3

4170-30-3

98-82-8

50-00-0

66-25-1

590-86-3

138-86-3

67-56-1

78-93-3

108-10-1

75-09-2

1330-20-7

123-72-8

529-20-4

95-47-6

99-87-6

99-83-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

2,5-Dimethyl benzaldehyde

3-Carene

Alpha-pinene

a-Terpene

Acetaldehyde *

Acetone

Acrolein *

Beta-pinene

Benzaldehyde

Benzene *

Bromomethane *

Butylaldehyde

Camphene

Chloroethane *

Chloroethene *

Chloroform

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

n-Butyraldehyde

o-Tolualdehyde

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

3.9n

4.7

BDL

BDL

0.0053f,y

0.043

1.4h

0.17f

0.075h

0.19h

0.023f,y

0.52h

0.12f,y

0.0076

BDL

0.029f,y

0.043

BDL

BDL

0.00010f

BDL

0.010f,y

0.0020f

0.14p

0.022f,y

0.018f,y

0.043

0.11q

BDL

0.0069

0.0018h

0.0048h

0.030f,y

0.011f,y

0.00045f

0.027h

0.043

D

E

E

E

D

E

D

D

E

D

E

D

E

E

E

E

E

D

E

E

E

D

D

D

D

E

E

E

D

E
Table 10.6.2-3 (cont.).

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.6.2-14 EMISSION FACTORS 2/2002

Rotary dryer, green,

direct wood-fired,

softwood (inlet

moisture content

>50%, dry basis)

(SCC 3-07-006-25)

(cont.)

104-87-0

108-95-2

123-38-6

100-42-5

108-88-3

110-62-3

p-Tolualdehyde

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

0.026f,y

0.028

0.013h

0.00036f

0.013h

0.014f,y

E

D

D

E

D

E

Rotary dryer, green,

direct wood-fired,

mixed species

(40-60% softwood,

40-60% hardwood)

 (inlet moisture

content >50%, dry

basis)

(SCC 3-07-006-26)

Uncontrolled

5779-94-2

13466-78-9

80-56-8

8006-64-2

75-07-0

67-64-1

107-02-8

127-91-3

100-52-7

71-43-2

123-72-8

156-59-2

4170-30-3

50-00-0

66-25-1

590-86-3

67-56-1

78-93-3

75-09-2

1330-20-7

529-20-4

95-47-6

99-87-6

104-87-0

108-95-2

123-38-6

100-42-5

108-88-3

110-62-3

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

2,5-Dimethyl benzaldehyde

3-Carene

Alpha-pinene

a-Terpene

Acetaldehyde *

Acetone

Acrolein *

Beta-pinene

Benzaldehyde

Benzene *

Bromomethane *

Butylaldehyde

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Tolualdehyde

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

p-Tolualdehyde

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

1.3h

1.6

BDL

BDL

0.0015f,y

0.040

0.51h

0.053f

0.059h

0.047h

0.015

0.11h

0.0082f,y

0.0047

BDL

0.0019f,y

BDL

BDL

BDL

0.0012

0.00082f,y

BDL

0.096h

0.0062f,y

0.0011f,y

BDL

0.059

0.0034

BDL

0.0014h

0.0058

0.00066f,y

0.00058

0.0016f

BDL

0.0046f,y

0.0079

0.0042h

0.00057

0.0059h

0.0040f,y

D

E

E

D

D

E

D

D

D

D

E

D

E

D

E

D

E

E

D

D

D

D

E

D

D

E

D

D

D

D

E
Table 10.6.2-3 (cont.).

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

EMISSION

FACTOR

RATING

6/2002 Wood Products Industry 10.6.2-15

Rotary dryer, green,

direct wood-fired,

mixed species

(40-60% softwood,

40-60% hardwood)

(inlet moisture

content >50%, dry

basis)

(SCC 3-07-006-26)

RTO

67-64-1

71-43-2

50-00-0

67-56-1

75-09-2

1330-20-7

 95-47-6

 

 

100-42-5

108-88-3

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.013

0.013

BDL

BDL

BDL

BDL

0.0033

BDL

BDL

0.00055

BDL

BDL

BDL

BDL

BDL 

BDL

BDL

0.00055

BDL

0.0019

BDL

BDL

0.00060

0.00075

0.00075

BDL

BDL

BDL

BDL

0.00074

0.00065

E

E

E

E

E

E

E

E

E

E

E

Rotary dryer, direct

natural gas-fired,

hardwood

(SCC 3-07-006-32)

Uncontrolled

50-00-0

THC as carbond

VOC as propanee

Formaldehyde *

0.21r

0.28

0.028s

E

E

E

Rotary dryer, direct

natural gas-fired,

softwood

(SCC 3-07-006-30)

Uncontrolled

50-00-0

67-56-1

THC as carbond

VOC as propanee

Formaldehyde *

Methanol *

1.6t

2.0

0.0086u

0.073u

D

E

E

E

Rotary dryer, green,

direct natural gasfired, softwood (inlet

moisture content

>50%, dry basis)

(SCC 3-07-006-31)

Uncontrolled

50-00-0

67-56-1

THC as carbond

VOC as propanee

Formaldehyde *

Methanol *

0.77v

0.94

0.0042v

BDL

E

E

E
Table 10.6.2-3 (cont.).

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.6.2-16 EMISSION FACTORS 2/2002

Rotary dryer, indirect

heated with auxiliary

natural gas, softwood

(SCC 3-07-006-35)

Uncontrolled

50-00-0

64-82-8

67-56-1

THC as carbond

VOC as propanee

Formaldehyde *

Methane

Methanol *

0.43w

0.30

0.047x

0.27f

0.027x

D

E

D

D

D

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 19 unless otherwise noted. See Table 10.6.2-8 for the hardwood and softwood

species commonly used in the production of particleboard and other composite wood products. Note: 

emission factors in table represent averages of data sets. The data spreadsheets, which may be

more useful for specific applications, are available on EPA’s Technology Transfer Network

(TTN) website at: http://www.epa.gov/ttn/chief/.

b

Emission control device: RTO = regenerative thermal oxidizer.

c CASRN = Chemical Abstracts Service Registry Number.

d

THC as carbon = total hydrocarbon measurements using EPA Method 25A.

e VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

f Reference 7.

g References 7, 9, 10, and 19.

h References 7 and 19.

j References 9 and 10.

k References 7, 9, 19, and 26.

m References 9, 19, and 26.

n References 7, 19, 20, and 21.

p References 7, 19, 20, 21, and 27.

q References 19 and 21.

r Reference 15.

s Reference 22.

t References 17 and 18.

u Reference 17.

v Reference 23.

w References 7 and 24.

x Reference 24.

y Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.
6/2002 Wood Products Industry 10.6.2-17

Table 10.6.2-4. EMISSION FACTORS FOR PARTICLEBOARD PRESSES AND BOARD

COOLERS--PARTICULATE MATTERa

Sourcec

Emission

Control

Device

Filterableb

Condensibled

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Hot press, UF

resin

(SCC 3-07-006-51)

Uncontrolled 0.20eD 0.016fE 0.23gD

Board cooler, UF

resin

(SCC 3-07-006-61)

Uncontrolled 0.15gD ND 0.077gD

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. Note: emission factors

in table represent averages of data sets. The data spreadsheets, which may be more useful for

specific applications, are available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b

Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c UF = urea formaldehyde.

d Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

e References 7, 26, 28, and 29.

f Reference 7.

g References 28 and 29.

Table 10.6.2-5. EMISSION FACTORS FOR PARTICLEBOARD PRESSES AND BOARD

COOLERS--NOx, CO, AND CO2

a

Sourceb

Emission

Control

DevicecNOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hot press, UF

resin

(SCC 3-07-006-51)

Uncontrolled

RTO

0.017d

0.092d

E

E

0.22e

0.090f

D

D

ND

ND

Board cooler, UF

resin

(SCC 3-07-006-61)

Uncontrolled ND 0.15gD ND

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. Note: emission factors

in table represent averages of data sets. The data spreadsheets, which may be more useful for

specific applications, are available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.
10.6.2-18 EMISSION FACTORS 2/2002

c

Emission control device: RTO = regenerative thermal oxidizer.

d Reference 26.

e References 7, 15, 19, 26, 28, and 29.

f References 19 and 26.

g

 References 28 and 29.
6/2002 Wood Products Industry 10.6.2-19

Table 10.6.2-6. EMISSION FACTORS FOR PARTICLEBOARD PRESSES AND BOARD

COOLERS--ORGANICSa

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

EMISSION

FACTOR

RATING

Hot press, UF

resin

(SCC 3-07-006-51)

Uncontrolled

5779-94-2

13466-78-9

75-07-0

67-64-1

107-02-8

80-56-8

100-52-7

71-43-2

127-91-3

123-72-8

79-92-5

4170-30-3

50-00-0

66-25-1

590-86-3

138-86-3

67-56-1

78-93-3

108-10-1

99-87-6

99-83-2

108-95-2

110-62-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

2,5-Dimethyl benzaldehyde

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzaldehyde

Benzene *

Beta-pinene

Bromomethane *

Butylaldehyde

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

0.79g

1.1

BDL

BDL

0.00032h,j

0.036

0.011k

0.029m

0.0054m

0.40

0.0018j,n

0.0030

0.11

BDL

0.0019j,n

0.044

BDL

BDL

BDL

0.00050h,j

BDL

0.23p

0.010j,n

0.0011h,j

0.036

0.59q

0.0052m

0.0099

BDL

BDL

BDL

0.035

0.036

0.011

BDL

BDL

BDL

0.0039h,j

C

D

E

D

D

D

D

D

E

D

D

E

D

E

C

E

E

D

D

D

D

D

D

D

E
Table 10.6.2-6 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.6.2-20 EMISSION FACTORS 2/2002

Hot press, UF

resin

(SCC 3-07-006-51)

RTO

50-00-0

108-95-2

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.018

0.027

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0054q

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0082

BDL

BDL

BDL

E

E

D

E
Table 10.6.2-6 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

EMISSION

FACTOR

RATING

6/2002 Wood Products Industry 10.6.2-21

Board cooler, UF

resin

(SCC 3-07-006-61)

Uncontrolled

75-07-0

67-64-1

107-02-8

80-56-8

100-52-7

123-72-8

4170-30-3

50-00-0

66-25-1

590-86-3

67-56-1

78-93-3

108-10-1

108-95-2

110-62-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzaldehyde

Benzene *

Beta-pinene

Bromomethane *

Butylaldehyde

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

0.069r

0.091

BDL

BDL

BDL

0.0036s

0.0083m

0.00036h,j

0.050

0.00042h,j

BDL

BDL

BDL

0.00060h,j

BDL

BDL

BDL

BDL

0.00029h,j

BDL

0.015t

0.0011h,j

0.00040h,j

BDL

0.081

0.00011h,j

0.0032

BDL

BDL

BDL

BDL

BDL

0.0066

BDL

BDL

BDL

0.0015h,j

D

E

D

D

E

D

E

E

E

D

E

E

D

E

E

D

E

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 19 unless otherwise noted. Note: emission factors in table represent averages of

data sets. The data spreadsheets, which may be more useful for specific applications, are
Table 10.6.2-6 (cont.).

10.6.2-22 EMISSION FACTORS 2/2002

available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c

Emission control device: RTO = regenerative thermal oxidizer.

d CASRN = Chemical Abstracts Service Registry Number.

e

THC as carbon = total hydrocarbon measurements using EPA Method 25A.

f VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

g References 7, 15, 19, 26, 28, 29, and 30.

h Reference 7.

j Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.

k References 7, 15, and 19.

m Reference 19.

n References 7 and 15.

p References 7, 15, 19, 26, 28, 29, 31, 32, 33, and 34.

q References 19 and 26.

r References 7, 28, 29, and 30.

s References 7 and 19.

t References 19, 28, and 29.
6/2002 Wood Products Industry 10.6.2-23

Table 10.6.2-7. EMISSION FACTORS FOR PARTICLEBOARD MISCELLANEOUS SOURCESa

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

Log storage

(SCC 3-07-008-95)

Uncontrolled PM, THC, VOC ND

Log debarking

(SCC 3-07-008-01)

Uncontrolled PM, THC, VOC ND

Log cutting

(SCC 3-07-008-02)

Uncontrolled PM, THC, VOC ND

Flaker/ refiner/

hammermill,

softwoods and

mixtures containing

softwoods

(SCC 3-07-006-64)

Uncontrolled

67-64-1

80-56-8

127-91-3

67-56-1

108-95-2

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.94

1.1

BDL

BDL

BDL

BDL

0.0064

BDL

0.49

BDL

0.15

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0073

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0045

BDL

BDL

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

D

E

D

D

D

D

E
Table 10.6.2-7 (cont.).

Source

Emission

Control

Deviceb CASRNcPollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

10.6.2-24 EMISSION FACTORS 2/2002

Sander

(SCC 3-07-006-65)

Uncontrolled

67-64-1

80-56-8

67-56-1

108-95-2

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.069

0.079

BDL

BDL

BDL

BDL

0.0051

BDL

0.048

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.013

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.015

BDL

BDL

BDL

lb/MSF

lb/MSF

lb/MSF

lb/MSF

lb/MSF

lb/MSF

E

E

E

E

E

E

Veneer press, UF

resin

(SCC 3-07-006-55)

(gluing veneer to

particle-board

substrate)

Uncontrolled 71-55-6

80-56-8

75-07-0

127-91-3

50-00-0

66-25-1

78-93-3

123-72-8

108-88-3

1,1,1-Trichloroethane *

Alpha-pinene

Acetaldehyde *

Beta-pinene

Formaldehyde *

Hexaldehyde

Methyl ethyl ketone *

n-Butylaldehyde

Toluene *

0.00022g

0.00054g

0.000099g

0.00011g

0.0062g

0.00017g,h

0.00020g

0.00014g,h

0.00047g

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

lb/MSF 3/4

E

E

E

E

E

E

E

E

E

a

Emission factors represent uncontrolled emissions unless otherwise noted. SCC = Source

Classification Code. * = hazardous air pollutant. ND = no data available. BDL = below test method

detection limit; indicates that this pollutant has not been detected in any test runs on this source. 

Reference 19 unless otherwise noted.

b

Emission control devices (baghouses) are considered no control for organic pollutants.

c CASRN = Chemical Abstracts Service Registry Number.
Table 10.6.2-7 (cont.).

6/2002 Wood Products Industry 10.6.2-25

d

Emission factor units: Pounds of pollutant per oven-dried ton of wood material (lb/ODT). One

lb/ODT = 0.5 kg/Mg (oven-dried). Pounds of pollutant per thousand square feet of panel (lb/MSF). 

One lb/MSF = 0.0049 kg/m2. Pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3.

e

THC as carbon = total hydrocarbon measurements using EPA Method 25A.

f VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

g Reference 15.

h Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.
10.6.2-26 EMISSION FACTORS 2/2002

Table 10.6.2-8. WOOD SPECIES COMMONLY USED IN 

COMPOSITE WOOD PRODUCTS MANUFACTURING a

Wood product AP-42 section Hardwood species Softwood species

Plywood 10.5 Oak, cherry, poplar, maple, larch Firs, pines

Oriented strandboard 10.6-1 Aspen Pines, firs, spruce

Particleboard 10.6-2 Aspen, oak Pines, firs

Medium density fiberboard 10.6-3 Gum, alder, hickory Pines, firs

Hardboard/fiberboard 10.6-4 Aspen, birch, beech, oak, maple Pines

Engineered wood products 10.9 Aspen, birch, poplar Pines, firs,

hemlock

a Reference 6.

References For Section 10.6.2

 1. T. M. Maloney, Modern Particleboard And Dry-Process Fiberboard Manufacturing, Miller

Freeman Publications, Inc., San Francisco, CA, 1977.

 2. J. G. Haygreen and J. L. Bowyer, Forest Products And Wood Science: An Introduction, Second

Edition, Iowa State University Press, Ames, IA, 1989.

 3. Written communication and attachments from T. A. Crabtree, Smith Engineering Company,

Broomall, PA, to P. E. Lassiter, U. S. Environmental Protection Agency, Research Triangle Park,

NC, July 26, 1996.

4. Technical Memorandum, Minutes of the October 12-13, 1993 BACT Technologies Workshop,

Raleigh, NC, sponsored by the American Forest and Paper Association, K. D. Bullock, Midwest

Research Institute, Cary, NC, October 1993.

5. A. E. Cavadeas, RTO Experience In The Wood Products Industry, presented at Environmental

Challenges: What’s New in the Wood Products Industry?, workshop sponsored by the American

Forest and Paper Association, Research Triangle Park, NC, February 4-5, 1997.

6. Emission Factor Documentation For AP-42 Chapter 10, Wood Products Industry, prepared for

the U. S. Environmental Protection Agency, OAQPS/EFIG, by Midwest Research Institute, Cary,

NC, July 2003.

7. Particleboard And Medium Density Fiberboard Air Emission Databases, Technical Bulletin No.

693, National Council of the Paper Industry for Air and Stream Improvement, Inc., New York,

NY, April 1995.
6/2002 Wood Products Industry 10.6.2-27

8. Engineering Emissions Testing For Particulate Performed On The #1 & 3 Dryer Cyclone

Exhausts And Engineering Emissions Testing For Methanol Performed On The Press Vents At

Temple Inland Corporation, Monroeville, Alabama, Test Dates February 10-14, 1997, prepared

for Temple Inland, by Air Techniques, Inc., ATI Job No. 97TO4908, 1997.

9. In-House Air Emissions Testing Of Primary Dryer Outlet, Hope Particleboard Plant, Hope,

Arkansas, Test Dates January 29-31, 1997, prepared for Temple-Inland Forest Products

Corporation, by Maxim Technologies, Inc., Project No. 1411700875A, March 14, 1997.

10. In-House Air Emissions Testing of Primary Dryer Outlet And RTO Press Vent Inlet, Hope

Particleboard Plant, Hope, Arkansas, Test Dates February 12-14, 1997, prepared for TempleInland Forest Products Corporation, by Maxim Technologies, Inc., Project No. 1411700875B,

March 17, 1997.

11. Stationary Source Sampling Report, Reference No. 6041A, Weyerhaeuser Company, Moncure,

North Carolina, Particulate Emissions And Plume Opacity Testing, Surface Line Electrified

Filter Bed Inlet And Stack, October 20, 1988, Entropy Environmentalists, Inc., Research Triangle

Park, North Carolina, November 8, 1988. 

12. Weyerhaeuser Company, Marshfield, Wisconsin, Stack Testing Report For Total Gaseous NonMethane Organic Compound Emissions (TGNOC), Test Date: March 19-23, 1990,

Cross/Tessitore & Associates, P.A., Orlando, Florida, 1990.

13. Report To Weyerhaeuser Company, Marshfield, Wisconsin, For Particulate & NOx Emissions

Testing, Door Core Dryer EFB Stack, December 20, 1991, Environmental Technology &

Engineering Corporation, Elm Grove, Wisconsin, 1992.

14. Stationary Source Sampling Report, Reference No. 6393A, Weyerhaeuser Company, Moncure,

North Carolina, Formaldehyde Emissions, Particulate Emissions, And Plume Opacity Testing,

Core Line EFB Inlet, Core Line Stack, And Surface Line Stack, August 9 And 11, 1989, Entropy

Environmentalists, Inc., Research Triangle Park, North Carolina, September 21, 1989.

15. Emission Test Report: HAP Emission Testing On Selected Sources At A Wood Furniture

Production Facility–Facility A, prepared for U. S. Environmental Protection Agency, Research

Triangle Park, North Carolina, by Roy F. Weston, Inc., April 1993.

16. Weyerhaeuser Company–Marshfield, Wisconsin, Door Core Dryer, Particulate Compliance

1996.4, Test Date October 19, 1996, prepared for Weyerhaeuser Company, by Weyerhaeuser

Company, Project No. 721-9640, December 12, 1996.

17. Title V Emissions Testing On The Furnish Dryer Exhaust, Georgia Pacific Corporation,

Panelboard Plant, Monticello, Georgia, February 13, 1996, prepared for CH2M Hill, by

Analytical Testing Consultants, Inc., Report No. 5743, March 13, 1996.

18. Report Of Air Emissions Tests For Louisiana-Pacific Corporation Silsbee Particleboard Facility

Core And Face Dryer Cyclones, Test Date September 23, 1997, prepared for Louisiana-Pacific

Corporation, by Environmental Monitoring Laboratories, Inc., October 18, 1997.
10.6.2-28 EMISSION FACTORS 2/2002

19. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part IV -

Particleboard, Technical Bulletin No. 771, National Council of the Paper Industry for Air and

Stream Improvement, Inc., Research Triangle Park, NC, 1999.

20. Emissions Test Report, Boise Cascade Corporation, Island City, Oregon, Green Furnish Dryer,

March 10 & 11, 1998, prepared for Boise Cascade Corporation, by BWR Associates, Inc.,

Project No. 98-042D, 1998.

21. Emissions Test Report, Willamette Industries Duraflake Division, Albany, Oregon, Boiler #1,

Green Dryer #1, And Green Dryer #2, Test Dates April 22-23 And 25-26, 1996, prepared for

Willamette Industries, by BWR Associates, Inc., Project No. 96-048X, 1996.

22. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Thru Door Core Dryer And Press

Testing, Formaldehyde Air Emissions 1996.4, Test Dates October 19 And 21, 1996, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9640, December 30,

1996. 

23. Emissions Test Report, Willamette Industries Duraflake Division, Millersburg (Albany), Oregon,

Green Dryer #3, Test Dates March 27-28, 1997, prepared for Willamette Industries, by BWR

Associates, Inc., Project No. 97-043D, 1997.

24. Emissions Test Report, Willamette Industries Duraflake Division, Albany, Oregon, Dry Dryers 1,

2, 3 And 4, Test Dates May 19-22, 1998, prepared for Willamette Industries, by BWR Associates,

Inc., Project No. 98-044D, 1998.

25. Source Emission Test Report, Dryer And Press Exhausts Allegheny MDF Limited Partnership,

Mt. Jewett, Pennsylvania, Test Dates October 22-24 And December 17, 1997, prepared for

Allegheny MDF Limited Partnership, by Galson Measurements, Galson Project No. 975540,

December 3, 1997.

26. In-House Air Emissions Testing Of The Diboll Particleboard Plant, Diboll, Texas, Test Dates

October 8-9 And 15, 1997, prepared for Temple-Inland Forest Products Corporation, by Maxim

Technologies, Inc., Project No. 9711254A, January 12, 1998.

27. Formaldehyde Methods Comparison, NCASI Acetylacetone Method Vs. EPA Method 0011,

Weyerhaeuser Company, Springfield, Oregon, MEC #3 Rotary Particle Dryer, Test Dates

February 27-28, 1996, prepared for Weyerhaeuser Company, by BWR Associates, Inc., 1996. 

28. Results Of The November 14-17, 1995 Air Emission Compliance Tests At The Louisiana-Pacific

Waferboard Plant In Missoula, Montana, prepared for Louisiana-Pacific Corporation, by

Interpoll Laboratories, Inc., Report No. 5-6833, December 27, 1995.

29. Results Of The May 9-12, 1994 Air Emission Compliance Tests At The Louisiana-Pacific

[Particleboard] Plant In Missoula, Montana, Report No. 4-2837, Interpoll Laboratories, Inc.,

Circle Pines, Minnesota, June 8, 1994.

30. Weyerhaeuser Company–Marshfield, Wisconsin, Steam-Thru Door Core Plant Press Vents, VOC

Compliance Testing 1998.3, Test Dates August 6-7, 1998, prepared for Weyerhaeuser Company,

by Weyerhaeuser Company, Project No. 721-9850, September 15, 1998.
6/2002 Wood Products Industry 10.6.2-29

31. Weyerhaeuser Company–Marshfield, Wisconsin, Door Core Press Scavenger Trials, Press Vent

Formaldehyde Air Emissions 1997.3, Test Dates July 21-24, 1997, prepared for Weyerhaeuser

Company, by Weyerhaeuser Company, Project No. 721-9741, 1997.

32. Weyerhaeuser Company–Marshfield, Wisconsin, Formaldehyde Emissions Variability Study,

Press Area Common Stack, Test Dates December 18, 1997 To March 26, 1998, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9753, May 26, 1998. 

33. Weyerhaeuser Company–Marshfield, Wisconsin, Formaldehyde Emissions Variability Study,

Press Area Common Stack, Test Dates April 1, 1998 To June 30, 1998, prepared for

Weyerhaeuser Company, by Weyerhaeuser Company, Project No. 721-9753, 1998.

34. Emission Test Report Particleboard Press And No. 2 Rotary Dryer (MEC Dryer With WoodFired Burner) Emissions Testing, International Paper, Decorative Products Division, Stuart,

Virginia, Test Dates June 8-10, 1998, prepared for International Paper Decorative Products

Division, by Roy F. Weston, Inc., Work Order No. 00157-045-002, June 1998.

35. Written communication from David Word, National Council of the Paper Industry for Air and

Stream Improvement, Inc., to Dallas Safriet, U. S. Environmental Protection Agency, Research

Triangle Park, NC, August 14, 2001.
8/2002 Wood Products Industry 10.6.3-1

10.6.3 Medium Density Fiberboard Manufacturing

10.6.3.1 General1-2,7 -

The Composite Panel Association defines medium density fiberboard (MDF) as a dry-formed

panel product manufactured from lignocellulosic fibers combined with a synthetic resin or other suitable

binder. The panels are compressed to a density of from 496 to 801 kilograms per cubic meter (kg/m3) (31

to 50 pounds per cubic foot [lb/ft3]) in a hot press. The entire interfiber bond is formed by a synthetic

resin or other suitable organic binder.

In contrast to particleboard, MDF has more uniform density throughout the board and has

smooth, tight edges that can be machined. It can be finished to a smooth surface and grain printed,

eliminating the need for veneers and laminates. Most of the thicker MDF panels (1.27 to

1.91 centimeters [cm]) (1/2 to 3/4 inch [in.]) are used as core material in furniture panels. Medium

density fiberboard panels thinner than 1.27 cm (1/2 in.) typically are used for siding.

10.6.3.2 Process Description2-7

The general steps used to produce MDF include mechanical pulping of wood chips to fibers

(refining), drying, blending fibers with resin and sometimes wax, forming the resinated material into a

mat, and hot pressing. Figure 10.6.3-1 presents a process flow diagram for a typical MDF plant.

The furnish for MDF normally consists of wood chips. Wood chips typically are delivered by

truck or rail from offsite locations such as sawmills, plywood plants, furniture manufacturing facilities,

satellite chip mills, and whole tree chipping operations. If wood chips are prepared onsite, logs are

debarked, cut to more manageable lengths, and then sent to chippers. If necessary, the chips are washed

to remove dirt and other debris.

Clean chips are softened in a steam-pressurized digester, then transported into a pressurized

refiner chamber. In the refiner chamber, single or double revolving disks are used to mechanically pulp

the softened chips into fibers suitable for making the board.

From the refiners, the fibers move to the drying and blending area. A rotary predryer may be

used for initial drying of relatively wet furnish. Regardless of whether or not a predryer is used, tube

dryers typically are used to reduce the moisture content of the fibers to desired levels. Single-stage or

multiple-stage tube drying systems are commonly used in MDF manufacture. Most of the multiple-stage

tube drying systems incorporate two stages. In multiple-stage tube dryers, there is a primary tube dryer

and a second stage tube dryer in series separated by an emission point such as a cyclonic collector. Heat

is usually provided to tube dryers by the direct firing of propane, natural gas, or distillate oil or by

indirect heating. 

The sequence of the drying and blending operations depends on the method by which resins and

other additives are blended with the fibers. Urea-formaldehyde (UF) resins are the most common resins

used in the manufacture of MDF. Phenolic resins, melamine resins, and isocyanates are also used. Some

plants inject resins into a short-retention blender, while most facilities inject resin formulations into a

blowline system. If resin is added in a separate blender, the fibers are first dried and separated from the

gas stream by a fiber recovery cyclone, then conveyed to the blender. The fibers then are blended with

resin, wax, and any other additives and conveyed to a dry fiber storage bin.

If a blowline system is used, the fibers are first blended with resin, wax, and other additives in a

blowline, which is a duct that discharges the resinated fibers to the dryer. After drying, the fibers are

separated from the gas stream by a fiber recovery cyclone and then conveyed to a dry fiber storage bin.
10.6.3-2 EMISSION FACTORS 8/2002

PRESSURIZED

DIGESTER

CHIP

WASHING

(OPTIONAL)

DRY FIBER

STORAGE

PRIMARY

TUBE

DRYER

(SCC 3-07-009-

21 to -40)

RESIN, WAX,

ADDITIVES

BLOW LINE

OR

FIBER

RECOVERY

CYCLONE

RESIN, WAX,

ADDITIVES

FORMING

(SCC 3-07-009-81, -82) PREPRESSING MAT

TRIMMING

WOOD RECYCLE

HOT PRESSING

(SCC 3-07-009-50, -60)

PACKAGING/

SHIPPING

PAINTING/

LAMINATING

(OPTIONAL)

TRIMMING,

SANDING,

SAWING

(SCC 3-07-009-83, -84)

BOARD

COOLING

WOOD RECYCLE

PRESSURIZED

REFINER

BLENDER

(SCC 3-07-009-

80)

OFF-SITE CHIP PREPARATION

ON-SITE CHIP PREPARATION

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC 3-07-008-02)

Chipping (SCC 3-07-014-82)

Chip storage (SCC 3-07-008-21)

SECOND STAGE TUBE

DRYER (OPTIONAL)

(SCC-3-07-009-37)

SECOND STAGE TUBE

DRYER (OPTIONAL)

(SCC-3-07-009-37)

CYCLONIC

SEPARATOR

FIBER

RECOVERY

CYCLONE

CYCLONIC

SEPARATOR

PRIMARY

TUBE

DRYER

(SCC 3-07-009-

21 to -40)

ROTARY

PREDRYER

(OPTIONAL)

(SCC 3-07-009-40)

Figure 10.6.3-3. Typical process flow diagram for a medium density fiberboard (MDF) plant.
8/2002 Wood Products Industry 10.6.3-3

Air conveys the resinated fibers from the dry storage bin to the forming machine, where they are

deposited on a continuously moving screen system. The continuously formed mat must be prepressed

before being loaded into the hot press. After prepressing, some pretrimming is done. The trimmed

material is collected and recycled to the forming machine.

The prepressed and trimmed mats then are transferred to the hot press. The press applies heat

and pressure to activate the resin and bond the fibers into a solid panel. The mat may be pressed in a

continuous hot press, or the precompressed mat may be cut by a flying cutoff saw into individual mats

that are then loaded into a multi-opening, batch-type hot press. Steam or hot oil heating of the press

platens is common in domestic MDF plants. After pressing, the boards are cooled, sanded, trimmed, and

sawed to final dimensions. The boards may also be painted or laminated. Finally, the finished product is

packaged for shipment.

10.6.3.3 Emissions And Controls2-18 -

The primary emission sources at MDF mills are fiber dryers and press vents. Other emission

sources may include boilers, chip production operations, and finishing operations such as sanding,

trimming, and laminate application. Wood storage piles are sources of fugitive PM and VOC emissions.

Most MDF mills have chips delivered from offsite locations. However, in mills where chips are

generated onsite, operations such as log debarking, sawing, chipping, and grinding, in addition to panel

trimming, sanding, and sawing generate particulate matter (PM) and PM less than 10 micrometers

(PM-10) emissions in the form of sawdust and wood particles. In addition, these processes may be

sources of PM less than 2.5 micrometers in aerodynamic diameter (PM-2.5) emissions.

The exhaust from dryers first is ducted to a fiber recovery cyclone before being emitted. 

Emissions can include wood dust and other solid PM, volatile organic compounds (VOCs), and

condensible PM. If direct-fired units are used, products of combustion such as carbon monoxide (CO),

carbon dioxide (CO2), and nitrogen oxides (NOx), are also emitted. The condensible PM and a portion of

the VOCs leave the dryer stack as vapor but condense at normal atmospheric temperatures to form liquid

particles or mist that creates a visible blue haze. Both the VOCs and condensible PM are primarily

compounds evaporated from the wood, with a minor constituent being combustion products. Quantities

emitted are dependent on wood species, dryer temperature, fuel used, and other factors including. season

of the year, time between logging and processing, and chip storage time.

Emissions from board hot presses are dependent on the type and amount of resin used to bind the

wood fibers together, as well as wood species, wood moisture content, wax and catalyst application rates,

and press conditions. When the press opens, vapors that may include resin ingredients, such as

formaldehyde and other VOCs, are released. The rate at which formaldehyde is emitted during pressing

and board cooling operations is a function of the amount of excess formaldehyde in the resin, board

thickness, press temperature, press cycle time, and catalyst application rates.

Emissions from finishing operations for MDF are dependent on the type of products being

finished. For most MDF products, finishing involves trimming to size, sanding, and in some cases

application of laminates. Other products may require sanding or the application of laminate surfaces

with spray adhesives. Trimming and sanding operations are sources of PM and PM-10 emissions. In

addition, these processes may be sources of PM-2.5 emissions. Limited data are available for MDF

sanding and sawing operations. Emission factors for plywood sanding and sawing operations may

provide an order of magnitude estimate for similar MDF sanding and sawing operations. Emissions from

adhesives used in the application of laminate surfaces are likely to include VOCs.
10.6.3-4 EMISSION FACTORS 8/2002

In MDF mills where wood chips are generated onsite, PM, PM-10, and PM-2.5 emissions from

log debarking, sawing, and grinding operations can be controlled through capture in an exhaust system

connected to a sized cyclone and/or fabric filter collection system. Emissions of PM, PM-10, and

PM-2.5 from sanding and final trimming operations can be controlled using similar methods. These

wood dust capture and collection systems are used not only to control atmospheric emissions, but also to

recover the dust as a by-product fuel for a boiler or dryer.

Methods of controlling PM emissions from MDF sources include absorption systems (wet

scrubbers), fabric filters, wet electrostatic precipitators (WESPs), and oxidation systems (discussed

below). The WESP uses electrostatic forces to attract pollutants to either a charged metal plate or a

charged metal tube. The collecting surfaces are continually rinsed with water to wash away the

pollutants. Wet PM control systems may achieve short-term reductions in emissions of some watersoluble organic compounds (such as formaldehyde). However, the ability of these wet systems to absorb

water-soluble compounds diminishes as the recirculating scrubbing liquid becomes saturated with these

compounds.

A VOC control technology commonly used in the wood products industry for controlling both

dryer and press exhaust gases is regenerative thermal oxidation. Thermal oxidizers destroy VOCs and

condensible organics by burning them at high temperatures. Thermal oxidizers also reduce CO emissions

in direct-fired dryer exhausts by oxidizing the CO in the exhaust to CO2 (a product of complete

combustion). Regenerative thermal oxidizers (RTOs) are designed to preheat the inlet emission stream

with heat recovered from the incineration exhaust gases. Up to 98 percent heat recovery is possible,

although 95 percent is typically specified. Gases entering an RTO are heated by passing through preheated beds packed with a ceramic media. A gas burner brings the preheated emissions up to an

incineration temperature between 788° and 871°C (1450° and 1600°F) in a combustion chamber with

sufficient gas residence time to complete the combustion. Combustion gases then pass through a cooled

ceramic bed where heat is extracted. By reversing the flow through the beds, the heat transferred from

the combustion exhaust air preheats the gases to be treated, thereby reducing auxiliary fuel requirements.

Regenerative catalytic oxidizers (RCOs) are also used to control VOCs from wood products

dryers and presses. Regenerative catalytic oxidizers function similar to RTOs, except that the heat

recovery beds in RCOs contain catalytic media. The catalyst accelerates the rate of VOC oxidation and

allows for VOC destruction at lower temperatures than in an RTO, typically 316° to 538°C (600° to

1000°F), which reduces auxiliary fuel usage. 

Thermal catalytic oxidizers (TCOs), which are a combination of an RTO and RCO, are also used

in the wood products industry. The TCO operates at a temperature of around 480°C (900°F) and

contains catalytic media. However, the heat recovery canisters and fans on the TCO are sized large

enough so that the TCO can be operated like an RTO (with non-catalytic ceramic media) if catalyst

replacement costs become overly expensive.

In addition to add-on thermal or catalytic oxidizers, exhaust gases from dryers and presses may

be routed to the combustion chamber of an onsite boiler or process heater. The VOC and CO emissions

in the process exhaust may be incinerated in the combustion chamber provided that the system is

designed to allow for sufficient mixing and residence time.

Fugitive PM emissions from road dust and uncovered bark and dust storage piles may be

controlled in a number of different ways. Some of these methods include enclosure, wet suppression

systems, and chemical stabilization.
8/2002 Wood Products Industry 10.6.3-5

Calculating PM-10 emissions from wood products industry emission sources is problematic due

to the relationship between PM-10 (or PM) emissions and VOC emissions from these processes. 

Because the Method 201A train (PM-10) operates with an in-stack cyclone and filter, organic materials

that are volatile at stack gas temperatures but that are condensed at back half impinger temperatures

(-20°C [-68°F]) are collected as condensible PM-10. However, these materials will also be measured as

VOC via Methods 25 and 25A, which operate with a heated or an in-stack filter. Hence, if PM-10 is

calculated as the sum of filterable and condensible material, some pollutants will be measured as both

PM-10 and VOC emissions. However, if only filterable material is considered to be PM-10, the PM-10

emission factors will be highly dependent on stack gas temperature. In this AP-42 section, PM-10 is

reported as front half catch only (Method 201A results only; not including Method 202 results). 

However, condensible PM results are also reported, and these results can be combined with the PM-10

results as appropriate for a specific application. Measured VOC emissions may be affected by the

sampling method and by the quantity of formaldehyde and other aldehydes and ketones in the exhaust;

formaldehyde is not quantified using Method 25A. Other low molecular weight oxygenated compounds

have reduced responses to Method 25A. Therefore, when VOC emissions are measured using

Method 25A, the emission rates will be biased low if low molecular weight oxygenated compounds are

present in significant concentrations in the exhaust stream. A more extensive discussion of these

sampling and analysis issues is provided in the Background Report for this section.

Guidance from EPA’s Emission Factor and Inventory Group (EFIG) indicates that when it is

possible, VOC emission factors should be reported in terms of the actual weight of the emitted

compound. However, when an actual molecular weight (MW) of the emitted stream is not feasible (as is

the case with the mixed streams emitted from wood products industry sources), the VOC should be

reported using an assumed MW of 44, and reported “as propane.” Each VOC-as-propane emission factor

is estimated by first converting the THC from a carbon basis to a propane basis. Propane (MW = 44)

includes 3 carbon atoms (total MW of 36) and 8 hydrogen atoms (total MW of 8). Every 36 pounds of

carbon measured corresponds to 44 pounds of propane. The ratio of the MW of propane to the MW of

carbon in propane is 44/36, or 1.22. The conversion is expressed by the following equation:

THC as pounds carbon × 44 pounds propane

36 pounds carbon = THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

After the THC emission factor has been converted from a carbon to a propane basis, the

formaldehyde emission factor is added (where available), then the available emission factors for

non-VOC compounds, including acetone, methane, and methylene chloride, are subtracted. This

procedure is expressed simply by the following equation:

VOC as propane = (1.22 × THC as carbon) + formaldehyde - (acetone + methane + methylene chloride)

In cases where no emission factor is available (or the emission factor is reported only as below the test

method detection limit, or “BDL”) for one or more of the compounds used to estimate the

VOC-as-propane value, adjustments to the converted THC value are made only for those compounds for

which emission factors are available. That is, a value of zero is inserted in the above equation for the

specified compounds where no emission factor is available, or where the emission factor is reported only

as BDL. For example, if no methane emission factor is available, the THC-as-carbon emission factor is

converted to THC-as-propane, formaldehyde is added, and only acetone and methylene chloride are

subtracted.
10.6.3-6 EMISSION FACTORS 8/2002

Table 10.6.3-1 presents emission factors for dryer emissions of PM, including filterable PM,

filterable PM-10, and condensible PM. Table 10.6.3-2 presents emission factors for dryer emissions of

NOx, CO, and CO2. Table 10.6.3-3 presents emission factors for dryer emissions of organic pollutants. 

The emission factors for dryer emissions are presented in units of pounds of pollutant per oven-dried ton

of wood material out of the dryer (lb/ODT). Table 10.6.3-4 presents emission factors for press and board

cooler emissions of PM, including filterable PM, filterable PM-10, and condensible PM. Table 10.6.3-5

presents emission factors for press emissions of NOx and CO. Table 10.6.3-6 presents emission factors

for press and board cooler emissions of organic pollutants. The units for the press and board cooler

emission factors are pounds of pollutant per thousand square feet of 3/4-inch thick panel produced

(lb/MSF 3/4). Table 10.6.3-7 presents emission factors for miscellaneous source emissions of organic

pollutants.

To the extent possible, separate emission factors for MDF dryers are presented in Tables 10.6.3-1

to -3 for hardwoods and softwoods. Hardwoods generally correspond to deciduous species. For MDF,

plywood, and other composite wood products, commonly used hardwoods include aspen, oak, poplar,

maple, cherry, alder, hickory, gum, beech, birch, larch, and basswood. The emission factors for

hardwood MDF dryers presented in this section are based largely on the drying of gum, alder, and

hickory furnish. Softwoods generally correspond to coniferous species. For MDF, plywood, and other

composite wood products, commonly used softwoods include pines, firs, and spruce. Pines and firs are

the most commonly used softwood species for MDF manufacturing.

Emission factors for specific mixes of wood species may be calculated by combining emission

factors for individual wood species in the ratio specific to a given application, as emission data for those

species become available. For example, an uncontrolled THC as carbon emission factor for an indirectheated tube dryer, blowline blending UF resin and processing 60 percent softwood and 40 percent

hardwood may be calculated using the THC as carbon emission factors for softwood (4.4 lb/ODT) and

hardwood (3.7 lb/ODT), and the ratio of 60 percent to 40 percent. The resultant emission factor, rounded

to two significant figures, would be 4.1 lb/ODT.
8/2002 Wood Products Industry 10.6.3-7

Table 10.6.3-1. EMISSION FACTORS FOR MDF DRYERS--PARTICULATE MATTERa

Sourcec

Emission

Control

Deviced

Filterableb

Condensiblee

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Tube dryer, indirectheated, blowline

blend, UF resin,

softwood

(SCC 3-07-009-32)

Uncontrolled

BH

BH/WESP

ND

ND

ND

0.60f

0.011h

0.013f

D

D

D

0.53g

0.14h

0.13f

D

D

D

Tube dryer, direct

wood-fired,

blowline blend, UF

resin, softwood

(SCC 3-07-009-23)

Uncontrolled 10.4jD 1.6jD 0.59jD

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. See Table 10.6.3-8 for

the hardwood and softwood species commonly used in the production of MDF and other composite

wood products. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s

Technology Transfer Network (TTN) website at: http://www.epa.gov/ttn/chief/.

b

Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c UF = urea formaldehyde.

d

Emission control device: BH = baghouse (fabric filter); WESP = wet electrostatic precipitator.

e Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

f Reference 8.

g References 8 and 9.

h Reference 9.

j Reference 10.
10.6.3-8 EMISSION FACTORS 8/2002

Table 10.6.3-2. EMISSION FACTORS FOR MDF DRYERS--NOx, CO, AND CO2

a

Sourceb

Emission 

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Tube dryer,

indirect-heated,

non-blowline blend,

softwood

(SCC 3-07-009-33)

Uncontrolled ND 0.11cD ND

Tube dryer,

indirect-heated,

blowline blend, UF

resin, softwood

(SCC 3-07-009-32)

Uncontrolled

Thermal oxidizer

ND

0.38dE

0.068c

1.6d

D

E

ND

ND

Tube dryer, direct

natural gas-fired,

non-blowline blend,

hardwood

(SCC 3-07-009-27)

Uncontrolled ND 0.20cD ND

Tube dryer, direct

wood-fired,

blowline blend, UF

resin, softwood

(SCC 3-07-009-23)

Uncontrolled ND 4.0eD ND

Rotary predryer,

direct natural gasfired, softwood

(SCC 3-07-009-40)

Uncontrolled ND 0.24cD ND

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. See Table 10.6.3-8 for

the hardwood and softwood species commonly used in the production of MDF and other composite

wood products. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s

Technology Transfer Network (TTN) website at: http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde

c Reference 11.

d Reference 12.

e Reference 10.
8/2002 Wood Products Industry 10.6.3-9

Table 10.6.3-3. EMISSION FACTORS FOR MDF DRYERS--ORGANICSa

Sourceb

Emission

Control

Device CASRNcPollutant

Emission

factor

EMISSION

FACTOR

RATING

Tube dryer, indirectheated, non-blowline

blend, softwood

(SCC 3-07-009-33)

Uncontrolled THC as carbond1.7 D

VOC as propanee2.1 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.055 D

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.085 D

Limonene BDL

67-56-1 Methanol * 0.74 D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL
Table 10.6.3-3 (cont.).

Sourceb

Emission

Control

Device CASRNcPollutant

Emission

factor

EMISSION

FACTOR

RATING

10.6.3-10 EMISSION FACTORS 8/2002

Tube dryer, indirectheated, blowline

blend, UF resin,

softwood

(SCC 3-07-009-32)

Uncontrolled THC as carbond4.4 D

VOC as propanee5.6 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

75-07-0 Acetaldehyde * 0.020fD

67-64-1 Acetone 0.025 D

Acrolein * BDL

80-56-8 Alpha-pinene 2.1 D

Benzene * BDL

127-91-3 Beta-pinene 0.43 D

Bromomethane * BDL

79-92-5 Camphene 0.12 D

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.22gC

Limonene 0.11 D

67-56-1 Methanol * 0.87 D

Methyl ethyl ketone * BDL

108-10-1 Methyl isobutyl ketone * 0.0049 D

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

108-95-2 Phenol * 0.023 D

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL

Tube dryer, indirectheated, blowline

blend, UF resin,

softwood

(SCC 3-07-009-32)

Thermal

oxidizer

75-07-0

50-00-0

Acetaldehyde *

Formaldehyde *

0.0051h

0.15h

E

E

Tube dryer, indirectheated, blowline

blend, UF resin,

hardwood

(SCC 3-07-009-36)

Uncontrolled

75-07-0

50-00-0

THC as carbond

VOC as propanee

Acetaldehyde *

Formaldehyde *

3.7j

4.8

0.013j

0.26j

D

E

D

D
Table 10.6.3-3 (cont.).

Sourceb

Emission

Control

Device CASRNcPollutant

Emission

factor

EMISSION

FACTOR

RATING

8/2002 Wood Products Industry 10.6.3-11

Tube dryer, direct

natural gas-fired,

non-blowline blend,

hardwood

(SCC 3-07-009-27)

Uncontrolled THC as carbond1.0 D

VOC as propanee1.2 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.016 D

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.0085 D

Limonene BDL

67-56-1 Methanol * 0.96 D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL

Tube dryer, direct

wood-fired, blowline

blend, UF resin,

softwood

(SCC 3-07-009-23)

Uncontrolled

50-00-0

THC as carbond

VOC as propanee

Formaldehyde *

4.8j

6.7

0.86j

D

E

D
Table 10.6.3-3 (cont.).

Sourceb

Emission

Control

Device CASRNcPollutant

Emission

factor

EMISSION

FACTOR

RATING

10.6.3-12 EMISSION FACTORS 8/2002

Tube dryer, second

stage, blowline

blend, indirectheated, softwood

(SCC 3-07-009-37)

Uncontrolled THC as carbond0.13 D

VOC as propanee0.18 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

75-07-0 Acetaldehyde * 0.0035 D

67-64-1 Acetone 0.0034 D

Acrolein * BDL

80-56-8 Alpha-pinene 0.055 D

71-43-2 Benzene * 0.00073 D

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.021 D

Limonene BDL

67-56-1 Methanol * 0.015 D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

108-88-3 Toluene * 0.00083 D
Table 10.6.3-3 (cont.).

Sourceb

Emission

Control

Device CASRNcPollutant

Emission

factor

EMISSION

FACTOR

RATING

8/2002 Wood Products Industry 10.6.3-13

Rotary predryer,

direct natural gasfired, softwood

(SCC 3-07-009-40)

Uncontrolled THC as carbond0.79 D

VOC as propanee0.95 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.019 D

Acrolein * BDL

80-56-8 Alpha-pinene 0.28 D

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.0076 D

Limonene BDL

67-56-1 Methanol * 0.025 D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL

a

Emission factor units are pounds of pollutant per oven-dried ton of wood material out of dryer

(lb/ODT). One lb/ODT = 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 11 unless otherwise noted. See Table 10.6.3-8 for the hardwood and softwood

species commonly used in the production of MDF and other composite wood products. Note: 

emission factors in table represent averages of data sets. The data spreadsheets, which may be

more useful for specific applications, are available on EPA’s Technology Transfer Network

(TTN) website at: http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c CASRN = Chemical Abstracts Service Registry Number.

d

THC as carbon = total hydrocarbon measurements using EPA Method 25A.

e VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.
Table 10.6.3-3 (cont.).

10.6.3-14 EMISSION FACTORS 8/2002

f References 11 and 12.

g References 11, 12, and 13.

h Reference 12.

j Reference 10.
8/2002 Wood Products Industry 10.6.3-15

Table 10.6.3-4. EMISSION FACTORS FOR MDF HOT PRESSES AND BOARD COOLERS--

PARTICULATE MATTERa

Sourcec

Emission

Control

Deviced

Filterableb

Condensiblee

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Hot press, UF resin

(SCC 3-07-009-60)

Uncontrolled

RTO

0.18f

0.040h

D

E

0.15g

 ND

D 0.20f

0.016h

D

E

Board cooler, UF resin

(SCC 3-07-009-71)

Uncontrolled 0.054gD 0.0038gE ND

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. Note: emission factors

in table represent averages of data sets. The data spreadsheets, which may be more useful for

specific applications, are available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b

Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c UF = urea formaldehyde.

d

Emission control device: RTO = regenerative thermal oxidizer.

e Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

f References 10 and 14.

g Reference 10.

h Reference 14.

Table 10.6.3-5. EMISSION FACTORS FOR MDF HOT PRESSES--NOx, CO, AND CO2

a

Sourceb

Emission

Control

DevicecNOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hot press, UF resin

(SCC 3-07-009-60)

Uncontrolled

RTO

0.030d

0.51e

E

E

0.034d

0.085e

E

E

ND

ND

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. ND = no data available. Note: emission factors

in table represent averages of data sets. The data spreadsheets, which may be more useful for

specific applications, are available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c

Emission control device: RTO = regenerative thermal oxidizer.

d Reference 10.

e Reference 14.
10.6.3-16 EMISSION FACTORS 8/2002

Table 10.6.3-6. EMISSION FACTORS FOR MDF HOT PRESSES AND BOARD COOLERS--

ORGANICSa

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

EMISSION

FACTOR

RATING

Hot press, UF resin

(SCC 3-07-009-60)

Uncontrolled

5779-94-2

75-07-0

67-64-1

107-02-8

100-52-7

123-72-8

4170-30-3

50-00-0

66-25-1

590-86-3

67-56-1

78-93-3

108-10-1

529-20-4

104-87-0

108-95-2

123-38-6

110-62-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

2,5-Dimethyl benzaldehyde

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzaldehyde

Benzene *

Beta-pinene

Bromomethane *

Butylaldehyde

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Tolualdehyde

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

p-Tolualdehyde

Phenol *

Propionaldehyde *

Styrene *

Toluene *

Valeraldehyde

0.29g

0.80

BDL

BDL

0.0025h

BDL

0.014j

0.029k

0.0012h

BDL

0.00055h

BDL

BDL

BDL

0.0024h

BDL

BDL

BDL

BDL

0.0011h

BDL

0.48m

0.0029h

0.0014h

BDL

0.56n

0.00059h

0.016k

BDL

BDL

0.00070h

BDL

BDL

BDL

0.0010h

0.027k

0.00054h

BDL

BDL

0.0024h

D

E

E

D

D

E

E

E

E

C

E

E

D

E

D

E

E

D

E

E

Hot press, UF resin

(SCC 3-07-009-60)

RTO

50-00-0

THC as carbone

VOC as propanef

Formaldehyde *

0.019p

0.032

0.0091p

E

E

E
Table 10.6.3-6 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

EMISSION

FACTOR

RATING

8/2002 Wood Products Industry 10.6.3-17

Board cooler, UF

resin

(SCC 3-07-009-71)

Uncontrolled

5779-94-2

75-07-0

67-64-1

107-02-8

100-52-7

123-72-8

4170-30-3

50-00-0

66-25-1

590-86-3

67-56-1

78-93-3

529-20-4

104-87-0

110-62-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

2,5-Dimethyl benzaldehyde

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzaldehyde

Benzene *

Beta-pinene

Bromomethane *

Butylaldehyde

Camphene

Chloroethene *

Cis-1,2-dichloroethylene

Crotonaldehyde

Cumene *

Formaldehyde *

Hexaldehyde

Isovaleraldehyde

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Tolualdehyde

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

p-Tolualdehyde

Phenol *

Propionaldehyde *

Stryene *

Toluene *

Valeraldehyde

0.077j

0.13

BDL

BDL

0.00019h

BDL

0.0010h

0.0092k

0.00022h

BDL

0.000099h

BDL

BDL

BDL

0.0014h

BDL

BDL

BDL

0.00026h

BDL

0.042q

0.00065h

0.00025h

BDL

0.025k

0.00011h

BDL

BDL

BDL

0.000065h

BDL

BDL

BDL

0.00017h

BDL

BDL

BDL

BDL

0.00048h

D

E

E

E

E

E

E

E

E

D

E

E

E

E

E

E

E

a

Emission factor units are pounds of pollutant per thousand square feet of 3/4-inch thick panel

(lb/MSF 3/4). One lb/MSF 3/4 = 0.26 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 10 unless otherwise noted. Note: emission factors in table represent averages of

data sets. The data spreadsheets, which may be more useful for specific applications, are
Table 10.6.3-6 (cont.).

10.6.3-18 EMISSION FACTORS 8/2002

available on EPA’s Technology Transfer Network (TTN) website at: 

http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c

Emission control device: RTO = regenerative thermal oxidizer.

d CASRN = Chemical Abstracts Service Registry Number.

e

THC as carbon = total hydrocarbon measurements using EPA Method 25A.

f VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

g References 10, 11, 14, 15, 16, and 17.

h Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.

j References 10 and 11.

k Reference 11.

m References 10, 11, 14, 15, 16, 17, and 18.

n References 11 and 17.

p Reference 14.

q References 10, 11, and 18.
8/2002 Wood Products Industry 10.6.3-19

Table 10.6.3-7. EMISSION FACTORS FOR MDF MISCELLANEOUS SOURCESa

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

Log storage

(SCC 3-07-008-95)

Uncontrolled PM, THC, VOC ND

Log debarking

(SCC 3-07-008-01)

Uncontrolled PM, THC, VOC ND

Log chipper,

hardwoode

(SCC 3-07-014-82)

Uncontrolled PM ND

THC as carbonf0.0041 lb/ODT E

VOC as propaneg0.0050 lb/ODT E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene BDL

3-Carene BDL

Acetaldehyde * BDL

Acetone BDL

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

Formaldehyde * BDL

Limonene BDL

67-56-1 Methanol * 0.0010 lb/ODT E

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL

Chip storage

(SCC 3-07-008-21)

Uncontrolled PM, THC, VOC ND
Table 10.6.3-7 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

10.6.3-20 EMISSION FACTORS 8/2002

Blender, UF resin

(SCC 3-07-009-80)

Uncontrolled 1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene BDL

3-Carene BDL

Acetaldehyde * BDL

Acetone BDL

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.010 lb/ODT E

Limonene BDL

67-56-1 Methanol * 0.48 lb/ODT E

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL
Table 10.6.3-7 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

8/2002 Wood Products Industry 10.6.3-21

Former without

blowline blending,

UF resin (includes

blender emissions)

(SCC 3-07-009-81)

Uncontrolled 1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.053 lb/ODT E

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.060 lb/ODT E

Limonene BDL

67-56-1 Methanol * 0.41 lb/ODT E

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL
Table 10.6.3-7 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

10.6.3-22 EMISSION FACTORS 8/2002

Former with

blowline blend, UF

resin

(SCC 3-07-009-82)

Uncontrolled THC as carbonf0.056 lb/ODT E

VOC as propaneg0.067 lb/ODT E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.0064 lb/ODT D

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.0051 lb/ODT D

Limonene BDL

67-56-1 Methanol * 0.017 lb/ODT D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL
Table 10.6.3-7 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

8/2002 Wood Products Industry 10.6.3-23

Sanderh

(SCC 3-07-009-83)

Uncontrolled THC as carbonf0.0074 lb/MSF E

VOC as propaneg0.0066 lb/MSF E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene* BDL

3-Carene BDL

Acetaldehyde * BDL

67-64-1 Acetone 0.0051 lb/MSF D

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.0027 lb/MSF D

Limonene BDL

67-56-1 Methanol * 0.0043 lb/MSF D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

108-95-2 Phenol * 0.0069 lb/MSF D

Propionaldehyde * BDL

100-42-5 Styrene * 0.0014 lb/MSF D

Toluene * BDL
Table 10.6.3-7 (cont.).

Sourceb

Emission

Control

DevicecCASRNdPollutant

Emission

Factor

Emission

Factor

Units

EMISSION

FACTOR

RATING

10.6.3-24 EMISSION FACTORS 8/2002

Saw and hoggerj

(SCC 3-07-009-84)

Uncontrolled THC as carbonf0.11 lb/MSFkE

VOC as propaneg0.13 lb/MSFkE

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene BDL

3-Carene BDL

Acetaldehyde * BDL

Acetone BDL

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

Formaldehyde * BDL

Limonene BDL

67-56-1 Methanol * 0.38 lb/MSFkE

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL

a Emission factor units: Pounds of pollutant per oven-dried ton of wood material (lb/ODT). One

lb/ODT = 0.5 kg/Mg (oven-dried). Pounds of pollutant per thousand square feet of panel (lb/MSF). 

One lb/MSF = 0.0049 kg/m2. Factors represent uncontrolled emissions unless otherwise noted. ND =

No data available. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 11. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s TTN

website at: http://www.epa.gov/ttn/chief/.

b UF = urea formaldehyde.

c

Emission control devices (baghouses) are considered no control for organic pollutants.

d CASRN = Chemical Abstracts Service Registry Number.

e Reference 20; based on data for hardboard log chipping operation (See Section 10.6.4).

f

THC as carbon = total hydrocarbon measurements using EPA Method 25A.
Table 10.6.3-7 (cont.).

8/2002 Wood Products Industry 10.6.3-25

g VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

h

Emission factors for MDF sanders in units of pounds per thousand square feet of panel produced

(surface area of one side, even though both sides sanded).

j Board trim saw and hogger for processing wood residue for recycle. Hoggers reduce the size of wood

residue by slicing or chopping.

k References 11 and 19; emission factors for MDF saw in units of pounds per thousand square feet of

reclaimed (trimmed) material; approximate MSF reclaimed (trimmed) = MSF from press × 3%.
10.6.3-26 EMISSION FACTORS 8/2002

Table 10.6.3-8. WOOD SPECIES COMMONLY USED IN 

COMPOSITE WOOD PRODUCTS MANUFACTURING a

Wood product AP-42 section Hardwood species Softwood species

Plywood 10.5 Oak, cherry, poplar, maple, larch Firs, pines

Oriented strandboard 10.6-1 Aspen Pines, firs, spruce

Particleboard 10.6-2 Aspen, oak Pines, firs

Medium density fiberboard 10.6-3 Gum, alder, hickory Pines, firs

Hardboard/fiberboard 10.6-4 Aspen, birch, beech, oak, maple Pines

Engineered wood products 10.9 Aspen, birch, poplar Pines, firs,

hemlock

a Reference 7.

References For Section 10.6.3

1. T. M. Maloney, Modern Particleboard And Dry-Process Fiberboard Manufacturing, Miller

Freeman Publications, Inc., San Francisco, CA, 1977.

2. J. G. Haygreen and J. L. Bowyer, Forest Products And Wood Science: An Introduction, Second

Edition, Iowa State University Press, Ames, IA, 1989.

3. O. Suchsland and G. E. Woodson, Fiberboard Manufacturing Practices In The United States,

Agriculture Handbook No. 640, U. S. Department of Agriculture, Forest Service, 1986.

4. C. C. Vaught, Evaluation Of Emission Control Devices At Waferboard Plants,

EPA-450/3-90-002, Control Technology Center, Office of Air Quality Planning and Standards,

U. S. Environmental Protection Agency, Research Triangle Park, NC, October 1990.

5. Written communication and attachments from T. A. Crabtree, Smith Engineering Company,

Broomall, PA, to P. E. Lassiter, U. S. Environmental Protection Agency, Research Triangle Park,

NC, July 26, 1996.

6. Technical Memorandum, Minutes of the October 12-13, 1993 BACT Technologies Workshop,

Raleigh, NC, sponsored by the American Forest and Paper Association, K. D. Bullock, Midwest

Research Institute, Cary, NC, October 1993.

7. Emission Factor Documentation For AP-42 Chapter 10, Wood Products Industry, prepared for

the U. S. Environmental Protection Agency, OAQPS/EFIG, by Midwest Research Institute, Cary,

NC, July 2003.

8. Report For PM-10 Emission Measurements From The Wood Fiber Dryers, SierraPine, Ltd.,

Rocklin, California, Test Dates April 10-13, 1995, prepared for SierraPine, Ltd., by Carnot, April

1995.
8/2002 Wood Products Industry 10.6.3-27

9. Report For 1996 PM-10 Emission Measurements For Emission Reduction Credits, SierraPine,

Ltd., Rocklin, California, Test Dates November 19-26, 1996, prepared for SierraPine, Ltd., by

Carnot, April 1997.

10. Particleboard And Medium Density Fiberboard Air Emission Databases, Technical Bulletin

No. 693, National Council of the Paper Industry for Air and Stream Improvement, Inc., New

York, NY, April 1995.

11. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part III -

Medium Density Fiberboard, Technical Bulletin No. 770, National Council of the Paper Industry

for Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.

12. Report Of Air Emissions And Inlet Loading Tests For Willamette Industries–Malverne MDF

Facility Line II Dryers Thermal Oxidizer, Malverne, Arkansas, Test Dates March 5-6, 1998,

prepared for Willamette Industries, by Environmental Monitoring Laboratories, April 3, 1998. 

13. Report For 1995 VOC Emission Compliance Tests At The Wood Fiber Dryers And Press Vents,

SierraPine, Ltd., Rocklin, California, Test Dates April 10-13, 1995 And May 17-19, 1995,

prepared for SierraPine, Ltd., by Carnot, May 1995.

14. Report Of Air Emissions And Inlet Loading Tests For Louisiana-Pacific Corporation Urania

MDF Plant, Urania, Louisiana, January 18 through 21, 1994, prepared by Environmental

Monitoring Laboratories, Ridgeland, Mississippi, February 1994.

15. Report Of VOC And Formaldehyde Emissions Test For Willamette Industries–Malverne MDF

Facility Line I Press Vent Baghouse, Malverne, Arkansas, Test Date July 24, 1998, prepared for

Willamette Industries, by Environmental Monitoring Laboratories, August 14, 1998.

16. Report Of VOC And Formaldehyde Emissions Test For Willamette Industries–Malverne MDF

Facility Line II Press Vent Baghouse, Malverne, Arkansas, Test Date September 10, 1998,

prepared for Willamette Industries, by Environmental Monitoring Laboratories, September 29,

1998.

17. Emissions Test Report, Willamette Industries MDF, Eugene, Oregon, Press Vents, Test Dates

November 13-14, 1996, prepared for Willamette Industries, by BWR Associates, Inc., Project

No. 96-165X, 1996.

18. Source Emission Test Report, Dryer And Press Exhausts Allegheny MDF Limited Partnership,

Mt. Jewett, Pennsylvania, Test Dates October 22-24 and December 17, 1997, prepared for

Allegheny MDF Limited Partnership, by Galson Measurements, Galson Project No. 975540,

December 3, 1997.

19. Written communication from David Word, National Council of the Paper Industry for Air and

Stream Improvement, Inc., to Dallas Safriet, U. S. Environmental Protection Agency, Research

Triangle Park, NC, August 14, 2001.

20. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part VI -

Hardboard/Fiberboard, Technical Bulletin No. 773, National Council of the Paper Industry for

Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.
9/2002 Wood Products Industry 10.6.4-1

10.6.4 Hardboard and Fiberboard Manufacturing

10.6.4.1 General1 -

Fiberboard is a low-density insulation board used for housing, roofing, and office furnishings. 

Hardboard is similar to fiberboard, except that hardboard is more dense than fiberboard. Hardboard is

used for applications in housing (e.g., exterior siding, garage doors, and interior door facings), furniture,

store fixtures, automotive interiors, and toys. The most frequently used raw material for production of

fiberboard products is wood chips which are first softened in a pressurized steam vessel (digester) and

then refined or pulped into wood fibers. The fibers may then be mixed with resin, formed into mats, and

pressed and/or dried to form panel products. Other materials may be added during manufacture to

improve certain properties such as stiffness, hardness, finishing properties, resistance to abrasion and

moisture, as well as to increase strength, durability and utility. 

Hardboard/fiberboard manufacturing falls under the Standard Industrial Classification (SIC)

Code 2493, for “Reconstituted Wood Products”, which also includes oriented strandboard, medium

density fiberboard, and particleboard. The North American Industrial Classification System (NAICS)

Code for hardboard/fiberboard is 321219, for “Reconstituted Wood Product Manufacturing”.

10.6.4.2 Process Description1 -

Hardboard products are manufactured through dry processing, wet processing, or wet/dry

processing. Fiberboard products are manufactured by wet processing. Dry processing involves dry mat

forming and pressing, while wet processing involves wet forming and wet pressing. Wet/dry processing

involves wet forming followed by dry pressing. Resin is used in wet hardboard and dry hardboard

processing. Resin is not used in wet/dry hardboard or wet fiberboard processing.

The following sections summarize dry process hardboard manufacturing, fiberboard and wet

process hardboard manufacturing, and the wet/dry hardboard manufacturing process.

Dry Process Hardboard -

The general steps used to manufacture dry process hardboard include mechanical pulping of

wood chips to fibers (digesting and refining), blending of fibers with resin and wax, drying, forming the

resinated material into a mat, hot pressing, heat treatment of the pressed boards, and humidification. 

Figure 10.6.4-1 presents a flow diagram for dry process hardboard manufacturing. 

The primary raw material used in hardboard is hardwood or softwood chips. In addition to wood

chips, shavings or sawdust may be used as a raw material. If wood chips are prepared onsite, logs are

debarked, cut to manageable lengths, and then sent to chippers. If necessary, the chips are washed to

remove dirt and other debris.

Clean chips are either processed in pressurized refiners or are softened by steam in a digester and

sent to atmospheric refiners. Pressurized refiners consist of a steaming vessel (digester) and of single or

double revolving disks to mechanically pulp (refine) the chips into fibers suitable for making the board. 

The wood chips are discharged under pressure from the digester section of the pressurized refiner into the

refiner section. The steam pressure is maintained throughout the entire refining process. Atmospheric

refiners also use revolving disks to pulp the chips into fibers, but steam pressure is not maintained in

atmospheric refiners.

Wax may be added to the wood chips in the digester. Phenol-formaldehyde (PF) resin and other

additives (if used) are added to the wood fiber during or immediately following refining. Most dry

process hardboard plants inject PF resin into a blowline that discharges the resinated fibers to a tube
10.6.4-2 EMISSION FACTORS 9/2002

ON-SITE CHIP PREPARATION

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC-3-07-008-02)

Chipping (SCC 3-07-014-82)

Chip storage (SCC 3-07-008-21)

DRY FIBER STORAGE BIN

DRY FORMER*

PRIMARY TUBE DRYER

(SCC 3-07-014-10, -15)

CHIP WASHER*

(Optional)

HOT PRESS

(SCC 3-07-014-40)

(SCC 3-07-007-07)

COOLER*

(Optional)

BAKING/TEMPERING OVEN

(SCC 3-07-014-20)

(SCC 3-07-007-08, -09)

HUMIDIFICATION KILN

(SCC 3-07-014-30)

FINISHING

Sanding (SCC 3-07-014-80)

Other finishing steps

DIGESTER/REFINER

(SCC 3-07-014-84)

OFF-SITE CHIP

PREPARATION

SECONDARY TUBE DRYER

(Optional)

(SCC 3-07-014-25)

Wax

Linseed oil (optional)

BLOWLINE

Resin, additives

* This process is a potential emission source; however, no emissions data specific to this process are available.

Figure 10.6.4-1. Dry hardboard manufacturing processes.

dryer. The turbulent conditions in the tube dryer facilitate mixing between the wood fibers and resin

droplets. After drying, the resinated fibers are conveyed to a dry fiber storage bin where they await

forming.

Single-stage or multiple-stage tube drying systems are most commonly used in dry process

hardboard manufacture. Most of the multiple-staged tube drying systems incorporate two stages. In

multiple-stage tube dryers, there is a primary tube dryer and a secondary tube dryer in series separated by

an emission point such as a cyclonic collector. Single-stage and double-stage tube dryers are shown in

Figures 10.6.4-2a and 10.6.4-2b. Hardboard primary tube dryers dry wood fibers from about 51 percent

moisture (dry basis) to around 20 percent moisture (dry basis) with dryer inlet temperatures ranging up to

246°C (475°F). Secondary tube dryers further dry the wood furnish to around 6 percent moisture (dry

basis). Heat is provided to the hardboard tube dryers by either direct-firing with wood residuals, gas, or

oil or by indirect-heating. Although less common than tube dryers, rotary dryers may also be used to dry

wood material for hardboard manufacture.
9/2002 Wood Products Industry 10.6.4-3

 Fiber to storage

Second-stage

exhaust

Cyclonic

collector

Fan

Rotary air lock

Secondary dryer

Burner or

heat

exchanger

Figure 10.6.4-2a. Single-stage tube dryer.

Dryer

exhaust

Cyclonic

collector

 Fiber to storage

Pressurized

refiner

Burner or Tube dryer

heat

exchanger

Blowpipe

Resin

Fan

Figure 10.6.4-2b. Double-stage tube dryer.

Rotary air lock

First-stage

exhaust

Cyclonic

collector

Pressurized

refiner

Burner or Primary dryer

heat

exchanger

Blowpipe

Resin

Fan

Rotary air lock

Resinated fibers exiting the drying system enter a forming machine where they are deposited on a

continuously moving conveyor. The mat is prepressed and trimmed before being loaded into the hot

press. The press applies heat and pressure to activate the PF resin and bond the fibers into a solid board. 

Dry process hardboard plants use a multi-opening batch press. The typical press cycle is about

4 minutes. The hardboard presses are heated by steam to a temperature of around 210°C (410°F). 

Following pressing, boards are routed through a board cooler at some plants. However, most plants do

not operate board coolers.
10.6.4-4 EMISSION FACTORS 9/2002

ON-SITE CHIP PREPARATION

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC-3-07-008-02)

Chipping (SCC 3-07-014-82)

Chip storage (SCC 3-07-008-21)

FIBERBOARD BOARD DRYER

(SCC 3-07-015-10, -12)

WET FORMER

(SCC 3-07-015-50)

STEAM DIGESTER*

(Optional)

MIXING CHEST*

FINISHING*

WASHER

(Optional)

(SCC 3-07-015-40)

OFF-SITE CHIP

PREPARATION

REFINER

(SCC 3-07-015-30)

Water, additives

* This process is a potential emission source; however, no emissions data specific to this process are available.

Figure 10.6.4-3. Process flow diagram for wet process fiberboard manufacturing.

Hardboard plants typically heat treat the pressed hardboard in a bake or tempering oven. The

purpose of heat treatment is to lower the moisture content of pressed hardboard to bone dry levels to

improve dimensional stability and enhance board mechanical properties. Linseed oil is sometimes

applied to the hardboard prior to heat treatment. Hardboard ovens are either indirect-heated or directfired and operate at temperatures up to 170°C (340°F). Humidification of boards is done immediately

following heat treatment to bring the board moisture content back into equilibrium with ambient air

conditions. Humidification kilns are often integrated with hardboard ovens (i.e., the boards coming out

of the hardboard oven go straight into the humidification kiln). Following humidification, the hardboard

is finished and packaged for shipment. Dry process hardboard densities range from 625 to 1,100

kilograms per cubic meter (kg/m3) (39 to 69 pounds per cubic foot [lb/ft3]).

Wet Process Fiberboard -

The general steps in production of fiberboard manufacture include pulping of hardwood or

softwood wood chips, wet forming, drying, and finishing. Fiberboard may be manufactured with bagasse

or other agricultural fiber instead of wood fiber. The bagasse fiberboard manufacturing process is

generally the same as the wood fiberboard manufacturing process. Figure 10.6.4-3 presents a flow

diagram for wet process fiberboard manufacturing. The discussion below focuses on the wood

fiberboard manufacturing process.
9/2002 Wood Products Industry 10.6.4-5

Wood chips for fiberboard may either be steamed in digesters or soaked in hot process water

before being ground into fiber in atmospheric refiners. From the refiners, fibers are sometimes washed

to remove wood sugars that might reduce the quality of the finished product. The refined and/or washed

fibers are sent to stock chests to await further processing. The fibers from the stock chests are mixed

with water and additives such as alum, starch, asphalt, and wax. Resins are not used in fiberboard

production. The wood fibers are bonded together by additives and substances naturally contained in the

wood. Alum aids in the precipitation of wax, asphalt, and rosin onto wood fibers. Bonds between these

substances and the wood fibers assist in holding the fiber mat together.

Once mixed with additives, the fiber slurry is sent to the forming machine. In the wet forming

process, the water-fiber mixture is metered onto a wire screen. Water is drained away by gravity and

with the aid of suction applied to the underside of the wire. The fiber mat along with the supporting wire

is moved to a room-temperature pre-press where excess water is squeezed out. Once pre-pressed, the

fiber mat may be cut to length and trimmed on the edges with high-pressure water jets.

The fiber mats, which are around 60 percent moisture (dry basis), are passed through a conveyortype board dryer where their moisture content is reduced to about 4 percent. Fiberboard board dryers

operate with inlet temperatures of around 230°C (450°F) and outlet temperatures of around 160°C

(320°F). Finished fiberboard density ranges from 190 to 380 kg/m3 (12 to 24 lb/ft3). Once dried, the

fiberboard is finished, trimmed, and may be painted or roll-coated with asphalt. Finally, the fiberboard is

packaged for shipment.

Wet Process Hardboard -

Production of wet process hardboard includes pulping of wood chips, wet forming, pressing, heat

treatment, humidification, and finishing. Phenol-formaldehyde resin, wax, and alum are used in wet

process hardboard manufacturing. Figure 10.6.4-4 presents a flow diagram for wet process hardboard

manufacturing. 

Hardwood or softwood chips may either be purchased from outside or generated onsite from

logs. The chips are washed to remove dirt and debris. The chips are then steam cooked under pressure

in digesters to soften the chips and liberate the wood sugars. After cooking, the softened chips are

refined in a single or double disc atmospheric refiner (referred to as the primary refiner), which grinds

the chips into fiber form. The fibers from the primary refiner are subsequently fed into stock washers,

which use water and pressure to wash out the wood sugars. After washing, the wood material is further

refined in a secondary refiner. Some plants may omit secondary refining.

Once refined, the wood fiber is mixed with water, alum, PF resin, and wax in stock or mix chests. 

The alum is added to the fiber slurry to control pH and help precipitate the resin and wax onto the fibers. 

The dilute slurry of fiber, additives, and water is routed to a wet forming machine. At some plants, the

forming machine may have separate header boxes where separate slurries may be used to make layers in

the hardboard mat. The top layer of the fiber mat is called an “overlay” and the bottom layer is called a

“substrate”. The wood fiber used to make the overlay undergoes additional refining prior to chemical

addition and dilution so that the top layer of the hardboard will have a smoother finish. The fiber slurry

from the substrate head box and the overlay head box are fed onto a moving wire screen (forming

machine) where they immediately begin to form a continuous fiber mat. Water drains through the wire

screen first by gravity and then by suction. The fiber mat is compressed with press rolls and further

dewatered. The edges of the fiber mat may be trimmed with water jets prior to hot pressing.
10.6.4-6 EMISSION FACTORS 9/2002

ON-SITE CHIP PREPARATION

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC-3-07-008-02)

Chipping (SCC 3-07-014-82)

Chip storage (SCC 3-07-008-21)

WET FORMER

(SCC 3-07-014-86)

SECONDARY REFINER*

(Optional)

CHIP WASHER*

(Optional)

WASHER*

HOT PRESS

(SCC 3-07-014-40)

(SCC 3-07-007-07)

BAKING/TEMPERING OVEN

(SCC 3-07-014-20)

(SCC 3-07-007-08, -09)

HUMIDIFICATION KILN

(SCC 3-07-014-30)

FINISHING

Sanding (SCC 3-07-014-80)

Other finishing steps

DIGESTER*

OFF-SITE CHIP

PREPARATION

MIXING CHEST*

REFINER*

Water, alum, resin, wax

* This process is a potential emission source; however, no emissions data specific to this process are available.

Figure 10.6.4-4. Process flow diagram for wet process hardboard manufacturing.

The carrying wire takes the fiber mats to a preloader to await pressing. The fiber mats are loaded

into the press. Water released from the mats during pressing cascades down the sides of the press and is

recycled. The fiber mats enter the press at a moisture content of about 120 percent (dry basis). Wet

process hardboard presses are typically multi-opening, steam-heated, batch presses. The hardboard mats

are pressed for roughly 8 minutes at around 200°C (390°F).

As with dry process hardboard, the wet process hardboard mats may be transported to baking or

tempering ovens where the mats are dried to “bone-dry” levels following pressing. Further drying of the

mats increases bonding and makes the hardboard more resistant to water. Once dried, the boards may be

cooled and are then rehumidified to prevent buckling and to improve the overall dimensional stability of

the boards. Final wet process hardboard densities range from 800 to 1,120 kg/m3 (50 to 70 lb/ft3).

Wet/Dry Process Hardboard -

Production of wet/dry process hardboard includes pulping of softwood or hardwood chips, wet

forming, drying, pressing, heat treatment, humidification, and finishing. Wet/dry process hardboard

production is similar to fiberboard production until the pressing step of the process is reached. The

pressing, heat treatment, and humidification steps in wet/dry hardboard production are similar to the
9/2002 Wood Products Industry 10.6.4-7

ON-SITE CHIP PREPARATION

Log storage (SCC 3-07-008-95)

Debarking (SCC 3-07-008-01)

Cutting (SCC-3-07-008-02)

Chipping (SCC 3-07-014-82)

Chip storage (SCC 3-07-008-21)

MIXING CHEST*

CHIP WASHER*

(Optional)

HARDBOARD BOARD

DRYING*

PREHEATER*

HOT PRESS

(SCC 3-07-014-42)

(SCC 3-07-007-07)

BAKING/TEMPERING OVEN

(SCC 3-07-014-20)

(SCC 3-07-007-08, -09)

FINISHING

Sanding (SCC 3-07-014-80)

Other finishing steps

DIGESTER/REFINER

(SCC 3-07-014-84)

OFF-SITE CHIP

PREPARATION

WET FORMER*

Water, additives

HUMIDIFICATION KILN

(SCC 3-07-014-30)

* This process is a potential emission source; however, no emissions data specific to this process are available.

Figure 10.6.4-5. Process flow diagram for wet/dry process hardboard manufacturing.

same steps in wet hardboard production. Raw materials used in the production of wet/dry hardboard

include wood chips and additives such as linseed oil, asphalt, and wax. No resin is used in the

production of wet/dry hardboard. Figure 10.6.4-5 presents a flow diagram for wet/dry process hardboard

manufacturing. 

Wood chips may either be purchased from offsite or generated onsite from logs. The chips are

washed to remove dirt and debris. The chips are then steam cooked under pressure in digesters. After

cooking, the chips are refined in primary and/or secondary refiners. Some plants may omit secondary

refining. Some plants may use pressurized refiners in lieu of stand-alone digesters and atmospheric

refiners.

Once refined the wood fiber is mixed with water and wax in stock or mix chests. The dilute

slurry of fiber, additives, and water is routed to a wet forming machine. As with the manufacture of wet

process hardboard, some plants may use separate substrate (bottom layer) and overlay (top layer) forming

header boxes to make a layered hardboard mat. The fiber slurry from the substrate head box and the

overlay head box are fed onto a moving wire screen (forming machine) where they immediately begin to

form a continuous fiber mat. Water drains through the wire screen first by gravity and then by suction. 
10.6.4-8 EMISSION FACTORS 9/2002

The fiber mat is compressed with press rolls which assist in further dewatering the mat. The edges of the

fiber mat may be trimmed with water jets prior to drying.

The fiber mats, which are around 60 percent moisture (dry basis), are passed through a conveyortype board dryer where their moisture content is reduced to around 4 percent. The board dryers operate

with inlet temperatures of around 230°C (450°F) and outlet temperatures of around 160°C (320°F). 

From the dryer, the fiber mats pass through a press predryer or preheat oven. The purpose of the

predryer is to reduce the mat moisture content in order to minimize the hot press cycle. Steam-heated

batch presses are used in wet/dry hardboard manufacturing. Press temperatures average around 140°C

(470°F) for press cycle times of nearly 4 minutes. As for dry and wet process hardboard, the wet/dry

process hardboard mats are heat treated in hardboard ovens and humidification kilns following pressing. 

Wet/dry process hardboard densities range from 720 to 1,150 kg/m3 (45 to 72 lb/ft3).

10.6.4.3 Emissions and Controls -

The primary emission sources at hardboard/fiberboard mills are tube dryers, rotary dryers,

hardboard ovens, board conveyor dryers, press preheat ovens, and hot presses. Other emission sources

may include boilers, chip and fiber production operations, mat formers, board coolers, humidification

kilns, and finishing operations such as sanding and trimming. Other potential emissions sources ancillary

to the manufacturing process may include wood chip storage piles and bins (including wood fuel), chip

handling systems, and resin storage and handling systems.

Emissions from tube dryers or rotary dryers that are exhausted from the product recovery cyclone

include wood dust and other solid PM, volatile organic compounds (VOCs), condensible PM, and

products of combustion such as carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxides

(NOx), if direct-fired units are used. The condensible PM and a portion of the VOCs leave the dryer

stack as vapor but condense at normal atmospheric temperatures to form liquid particles or mist that

creates a visible blue haze. Both the VOCs and condensible PM are primarily compounds evaporated

from the wood or from the resin if resinated fibers are dried, with a minor constituent being combustion

products. Quantities emitted are dependent on wood species, dryer temperature, fuel used, and other

factors including season of the year, time between logging and processing, and chip storage time.

Unlike tube dryers and rotary dryers, hardboard ovens, board conveyor dryers, and press

preheaters process fiber mats or pressed boards and do not rely on pneumatic conveyance of fibers

through the dryers. Thus, there is less potential for emissions of PM from hardboard ovens, conveyor

dryers, and press preheaters. However, these dryers are sources of VOCs, CO, CO2, NOx, and other

organic compounds. The emissions from hardboard ovens, conveyor dryers, and press preheaters depend

on whether the dryer is indirect-heated or direct-fired, the fuel used if the dryer if direct-fired, wood

species, and type of resin, binder, or drying oil employed.

Emissions from board hot presses are dependent on the type and amount of resin (if any) used to

bind the wood fibers together, as well as wood species, wood moisture content, additives used, and press

conditions. When the press opens, vapors that may include resin ingredients (if resins are used) such as

formaldehyde, phenol, and other organic compounds are released. The rate at which organic compounds

are emitted during pressing operations is a function of the resin formulation, board thickness, press

temperature, and press cycle time.

A VOC control technology commonly used in the wood products industry for controlling both

dryer and press exhaust gases is regenerative thermal oxidation. Thermal oxidizers destroy VOCs and

condensible organics by burning them at high temperatures. Thermal oxidizers also reduce CO emissions

in direct-fired dryer exhausts by oxidizing the CO in the exhaust to CO2 (a product of complete
9/2002 Wood Products Industry 10.6.4-9

combustion). Regenerative thermal oxidizers (RTOs) are designed to preheat the inlet emission stream

with heat recovered from the incineration exhaust gases. Up to 98 percent heat recovery is possible,

although 95 percent is typically specified. Gases entering an RTO are heated by passing through preheated beds packed with a ceramic media. A gas burner brings the preheated emissions up to an

incineration temperature between 788° and 871°C (1450° and 1600°F) in a combustion chamber with

sufficient gas residence time to complete the combustion. Combustion gases then pass through a cooled

ceramic bed where heat is extracted. By reversing the flow through the beds, the heat transferred from

the combustion exhaust air preheats the gases to be treated, thereby reducing auxiliary fuel requirements.

Regenerative catalytic oxidizers (RCOs) are also used to control VOCs from hardboard dryers

and presses. Regenerative catalytic oxidizers function similar to RTOs, except that the heat recovery

beds in RCOs contain catalytic media. The catalyst accelerates the rate of VOC oxidation and allows for

VOC destruction at lower temperatures than in an RTO, typically 316° to 538°C (600° to 1,000°F),

which reduces auxiliary fuel usage.

Biofiltration systems are also used effectively for control of a variety of pollutants including 

organic compounds, NOx, CO, and PM from press exhaust streams. Biofiltration uses microrganisms

immobilized in a biofilm layer on a porous packing such as bark, wood chips, or synthetic media. 

Typical biofilter design consists of a three- to six-foot deep bed of media suspended over an air

distribution plenum. Exhaust gases entering the plenum are evenly distributed through the moist biofilter

media. As the contaminated vapor stream passes through the biofilter media, pollutants are transferred

from the vapor to the biofilm and, through microbiological degradation, are converted to CO2, water, and

salts. The microorganisms cannot easily attack pollutants in the gas phase; therefore, less water soluble

compounds (such as pinenes) are generally more difficult to control using a biofilter than are the more

water-soluble compounds (such as formaldehyde).

In addition to the control devices mentioned above, absorption systems such as scrubbers are

often used to control PM from hardboard/fiberboard dryers and presses.

Operations such as log chipping, in addition to chip piles and bins, and chip handling systems

generate particulate matter (PM) and PM less than 10 micrometers in aerodynamic diameter (PM-10)

emissions in the form of sawdust and wood particles. In hardboard/fiberboard mills where log chipping

is performed onsite, PM and PM-10 emissions from log debarking, sawing, and grinding operations can

be controlled through capture in an exhaust system connected to a fabric filter collection system. 

Emissions of PM and PM-10 from final sanding and sawing operations can be controlled using similar

methods. These wood dust capture and collection systems are used not only to control atmospheric

emissions, but also to recover the dust as a by-product fuel for a boiler or direct-fired dryer burners.

Fiber production operations such as digesters, pressurized refiners, atmospheric refiners, and

fiber washers may be sources of organic emissions. Emissions from these sources are typically

uncontrolled, except for pressurized refiners that vent directly into tube dryers at dry process hardboard

plants. When exhausted through a tube dryer, the pressurized refiner exhaust exits through the tube dryer

control device.

Hardboard/fiberboard mat forming systems may also emit small amounts of organic emissions,

and PM emissions in the case of dry forming systems. Emission factors for wet forming vacuum systems

are provided in this section. No emission factors are available for dry hardboard formers; however, the

magnitude of the emissions from dry formers may be comparable to the emissions from dry formers used

to form other reconstituted wood products (e.g., medium density fiberboard).
10.6.4-10 EMISSION FACTORS 9/2002

Hardboard board coolers and humidification kilns may also be sources of organic emissions. 

Exhaust from board coolers is typically uncontrolled or is routed to the press control device. No

emission factors are available specifically for hardboard board coolers, but emission factors are available

for particleboard and MDF board coolers. Humidification kilns are usually uncontrolled. Emission

factors for humidification kilns are provided in this section.

Emissions from hardboard/fiberboard finishing operations are dependent on the type of products

being finished. For most hardboard/fiberboard products, finishing involves cutting to size and, in some

cases, application of edge seals, anti-skid coatings, primers, company logos, or trademark or grade

stamps. Some products may require sanding. Sawing and sanding operations are sources of PM and

PM-10 emissions. No data specific to hardboard/fiberboard sawing are available. However, emission

factors for MDF sawing operations may provide an order of magnitude estimate for similar

hardboard/fiberboard sawing operations. Available emission factors for sanding of hardboard are

presented in this section.

Fugitive PM emissions from road dust and uncovered bark and dust storage piles may be

controlled in a number of different ways. Some of these methods include enclosure, wet suppression

systems, and chemical stabilization.

Calculating PM-10 emissions from wood products industry emission sources is problematic due

to the relationship between PM-10 (or PM) emissions and VOC emissions from these processes. 

Because the Method 201A train (PM-10) operates with an in-stack cyclone and filter, organic materials

that are volatile at stack gas temperatures but that are condensed at back half impinger temperatures

(-20°C [-68°F]) are collected as condensible PM-10. However, these materials will also be measured as

VOC via Methods 25 and 25A, which operate with a heated or an in-stack filter. Hence, if PM-10 is

calculated as the sum of filterable and condensible material, some pollutants will be measured as both

PM-10 and VOC emissions. However, if only filterable material is considered to be PM-10, the PM-10

emission factors will be highly dependent on stack gas temperature. In this AP-42 section, PM-10 is

reported as front half catch only (Method 201A results only; not including Method 202 results). 

However, condensible PM results are also reported, and these results can be combined with the PM-10

results as appropriate for a specific application. Measured VOC emissions may be affected by the

sampling method and by the quantity of formaldehyde and other aldehydes and ketones in the exhaust;

formaldehyde is not quantified using Method 25A. Other low molecular weight oxygenated compounds

have reduced responses to Method 25A. Therefore, when VOC emissions are measured using

Method 25A, the emission rates will be biased low if low molecular weight oxygenated compounds are

present in significant concentrations in the exhaust stream. A more extensive discussion of these

sampling and analysis issues is provided in the Background Report for this section.

Guidance from EPA’s Emission Factor and Inventory Group (EFIG) indicates that when it is

possible, VOC emission factors should be reported in terms of the actual weight of the emitted

compound. However, when an actual molecular weight (MW) of the emitted stream is not feasible (as is

the case with the mixed streams emitted from wood products industry sources), the VOC should be

reported using an assumed MW of 44, and reported “as propane.” Each VOC-as-propane emission factor

is estimated by first converting the THC from a carbon basis to a propane basis. Propane (MW = 44)

includes 3 carbon atoms (total MW of 36) and 8 hydrogen atoms (total MW of 8). Every 36 pounds of

carbon measured corresponds to 44 pounds of propane. The ratio of the MW of propane to the MW of

carbon in propane is 44/36, or 1.22. The conversion is expressed by the following equation:
9/2002 Wood Products Industry 10.6.4-11

THC as pounds carbon × 44 pounds propane

36 pounds carbon = THC as pounds propane

or

THC as pounds carbon × 1.22 = THC as pounds propane

After the THC emission factor has been converted from a carbon to a propane basis, the

formaldehyde emission factor is added (where available), then the available emission factors for

non-VOC compounds, including acetone, methane, and methylene chloride, are subtracted. This

procedure is expressed simply by the following equation:

VOC as propane = (1.22 × THC as carbon) + formaldehyde - (acetone + methane + methylene chloride)

In cases where no emission factor is available (or the emission factor is reported only as below the test

method detection limit, or “BDL”) for one or more of the compounds used to estimate the VOC-aspropane value, adjustments to the converted THC value are made only for those compounds for which

emission factors are available. That is, a value of zero is inserted in the above equation for the specified

compounds where no emission factor is available, or where the emission factor is reported only as BDL. 

For example, if no methane emission factor is available, the THC-as-carbon emission factor is converted

to THC-as-propane, formaldehyde is added, and only acetone and methylene chloride are subtracted.

Table 10.6.4-1 presents emission factors for dryer emissions of PM, including filterable PM and

condensible PM. Table 10.6.4-2 presents emission factors for dryer and oven emissions of NOx, CO, and

CO2. Table 10.6.4-3 presents emission factors for dryer and oven emissions of VOC and speciated

organic compounds. Table 10.6.4-4 presents emission factors for hardboard press emissions of PM,

including filterable PM, filterable PM-10, and condensible PM. Table 10.6.4-5 presents emission

factors for hardboard press emissions of NOx, CO, and CO2. Table 10.6.4-6 presents emission factors for

hardboard press emissions of VOC and speciated organic compounds. Table 10.6.4-7 presents emission

factors for miscellaneous sources of PM, including filterable PM, filterable PM-10, and condensible PM. 

Table 10.6.4-8 presents emission factors for miscellaneous source emissions of NOx, CO, and CO2. 

Table 10.6.4-9 presents emission factors for miscellaneous source emissions of VOC and speciated

organic compounds.

To the extent possible, separate emission factors for hardboard and fiberboard dryers are

presented in Tables 10.6.4-1 to -3 for hardwoods and softwoods. Hardwoods generally correspond to

deciduous species. For hardboard, fiberboard, plywood, and other composite wood products, commonly

used hardwoods include aspen, oak, poplar, maple, cherry, alder, hickory, gum, beech, birch, and

basswood. The emission factors for hardwood hardboard and fiberboard dryers presented in this section

are based largely on the drying of aspen, birch, beech, oak, and maple furnish. Softwoods generally

correspond to coniferous species. For hardboard, fiberboard, plywood, and other composite wood

products, commonly used softwoods include pines, firs, and spruce. Pines are the most commonly used

softwood species for hardboard and fiberboard manufacturing.
10.6.4-12 EMISSION FACTORS 9/2002

Table 10.6.4-1. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD DRYERS AND

OVENS—PARTICULATE MATTERa

Source

Emission

Control

Device

Filterableb

Condensiblec

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Tube dryer, direct

natural gas-fired,

blowline blend, PF

resin, hardwood

(SCC 3-07-014-15)

None 1.9 E ND 0.57 E

a Emission factor units: pounds of pollutant per oven-dried ton of wood material (lb/ODT); one lb/ODT

= 0.5 kg/Mg (oven-dried). Factors represent uncontrolled emissions. SCC = Source Classification

Code. ND = no data available. Reference 2. See Table 10.6.4-10 for the hardwood and softwood

species commonly used in the production of hardboard, fiberboard, and other composite wood

products. Note: emission factors in table represent averages of data sets. The data spreadsheets,

which may be more useful for specific applications, are available on EPA’s TTN website at: 

http://www.epa.gov/ttn/chief/.

b Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).
9/2002 Wood Products Industry 10.6.4-13

Table 10.6.4-2. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD DRYERS,

OVENS—NOx, CO, AND CO2

a

Source

Emission

Control

Deviceb

Emission

Factor

Unitsc NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hardboard tube dryer,

direct natural gasfired, blowline blend,

PF resin, hardwood

(SCC 3-07-014-15)

Uncontrolled lb/ODT 0.44d E 0.067d E 384d E

Hardboard tube dryer,

direct wood-fired,

blowline blend, PF

resin, hardwood

(SCC 3-07-014-10)

Uncontrolled lb/ODT ND 0.085 E ND

Hardboard tube dryer,

second stage, indirectheated, hardwood

(SCC 3-07-014-25)

Uncontrolled lb/ODT ND 0.076 E ND

Hardboard board

dryer, direct naturalgas fired, linseed oil

binder, heated zones,

softwood

(SCC 3-07-014-16)

Uncontrolled lb/MSF 1/2 ND 0.49e E ND

Hardboard tempering

oven, direct natural

gas-fired, hardwood

(SCC 3-07-014-20)

Uncontrolled

RTO

lb/MSF 1/8

lb/MSF 1/8

ND

ND

0.11

0.0021

E

E

ND

ND

Fiberboard board

dryer, indirect heated,

starch binder, heated

zones, softwood

(SCC 3-07-015-10)

Uncontrolled lb/MSF 1/2 ND 0.092 E ND

Fiberboard board

dryer, indirect heated,

6-12% asphalt binder,

heated zones,

softwood

(SCC 3-07-015-12)

Uncontrolled lb/MSF 1/2 ND 0.029e E ND

a Factors represent uncontrolled emissions unless otherwise noted. SCC = Source Classification Code. 

ND = no data available. Reference 3 unless otherwise noted. See Table 10.6.4-10 for the hardwood

and softwood species commonly used in the production of hardboard, fiberboard, and other composite

wood products. Note: emission factors in table represent averages of data sets. The data

spreadsheets, which may be more useful for specific applications, are available on EPA’s TTN

website at: http://www.epa.gov/ttn/chief/.

b Emission control device: RTO = regenerative thermal oxidizer.

c Emission factor units: pounds of pollutant per oven-dried ton of wood material (lb/ODT); one lb/ODT

= 0.5 kg/Mg (oven-dried); pounds of pollutant per thousand square feet of 1/2-inch thick panel
10.6.4-14 EMISSION FACTORS 9/2002

(lb/MSF 1/2); one lb/MSF 1/2 = 0.38 kg/m3; pounds of pollutant per thousand square feet of 1/8-inch

thick panel (lb/MSF 1/8); one lb/MSF 1/8 = 1.54 kg/m3.

d Reference 2.

e Emission factors apply only to the heated zones of the dryer; the cooling sections also have emissions

but data were not available for cooling section emissions.
9/2002 Wood Products Industry 10.6.4-15

Table 10.6.4-3. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD DRYERS,

OVENS—ORGANICSa

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

Hardboard tube

dryer, direct

natural gas-fired,

blowline blend, PF

resin, hardwood

(SCC 3-07-014-15)

None

75-07-0

67-64-1

107-02-8

71-43-2

74-87-3

100-41-4

50-00-0

66-25-1

67-56-1

78-93-3

108-95-2

123-38-6

100-42-5

108-88-3

75-69-4

1330-20-7

THC as carbond

VOC as propanee

Acetaldehyde *

Acetone

Acrolein *

Benzene *

Benzo(a)pyrene

Bromomethane *

Chloromethane *

Ethanol

Ethylbenzene *

Formaldehyde * 

Hexaldehyde

Isobutanol

m,p-Cresol *

Methanol *

Methyl ethyl ketone *

Methyl propyl ketone 

Methylene chloride *

Naphthalene *

o-Cresol *

Phenol *

Propanol

Propionaldehyde *

Pyridine

Styrene *

Toluene *

Trichlorofluoromethane

Xylenes *

3.2f

5.0

0.0096f

0.0095f

0.0041f,g

0.000088f

BDL

BDL

0.000019f

BDL

0.00013f

1.1f,g

0.052f,g

BDL

BDL

1.4f

0.00083f

BDL

BDL

BDL

BDL

0.056f

BDL

0.041f

BDL

0.0027f

0.00023f

0.000020f

0.000056f

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

10.6.4-16 EMISSION FACTORS 9/2002

Hardboard tube

dryer, direct woodfired, blowline

blend, PF resin,

hardwood

(SCC 3-07-014-10)

None

75-07-0

67-64-1

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.74

1.1

BDL

BDL

BDL

0.11

0.018

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.26

BDL

1.0

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.083

BDL

BDL

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

D

E

D

D

D

D

D
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-17

Hardboard tube

dryer, second

stage, indirectheated, hardwood

(SCC 3-07-014-25)

None

67-64-1

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl isobutyl ketone *

Methyl ethyl ketone *

Methylene chloride *

m,p,-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.23

0.27

BDL

BDL

BDL

BDL

0.031

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.017

BDL

0.042

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.039

BDL

BDL

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

D

E

D

D

D

D
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

10.6.4-18 EMISSION FACTORS 9/2002

Hardboard board

dryer, direct

natural-gas fired,

linseed oil binder

(heated zones),

softwood

(SCC 3-07-014-16)

None

75-07-0

67-64-1

107-02-8

71-43-2

50-00-0

67-56-1

78-93-3

108-10-1

108-95-2

123-38-6

100-42-5

108-88-3

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

BDL

BDL

BDL

0.053h

0.021h

0.037h

BDL

0.0021h

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.059h

BDL

0.047h

0.0013h

0.0034h

BDL

BDL

BDL

BDL

BDL

0.0019h

0.025h

0.00016h

0.0010h

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

E

E

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-19

Hardboard

tempering oven,

direct natural gasfired

(SCC 3-07-014-20)

None

75-07-0

67-64-1

107-02-8

50-00-0

67-56-1

78-93-3

108-10-1

108-95-2

123-38-6

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.50

0.61

BDL

BDL

BDL

0.076

0.0034

0.024

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0043

BDL

0.015

0.00075

0.0046

BDL

BDL

BDL

BDL

BDL

0.0019

0.10

BDL

BDL

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

E

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

10.6.4-20 EMISSION FACTORS 9/2002

Hardboard

tempering oven,

direct natural gasfired

(SCC 3-07-014-20)

RTO

67-64-1

67-56-1

108-95-2

THC as carbond

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

BDL

BDL

BDL

BDL

BDL

0.00091

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.00087

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0020

BDL

BDL

BDL

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

E

E

E
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-21

Fiberboard board

dryer, indirect

heated, starch

binder (heated

zones), softwood

(SCC 3-07-015-10)

None

75-07-0

67-64-1

107-02-8

80-56-8

50-00-0

67-56-1

108-95-2

123-38-6

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.063h

0.082h

BDL

BDL

BDL

0.00097h

0.0038h

0.00057h

0.013h

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0093h

BDL

0.017h

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0012h

0.00069h

BDL

BDL

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-3 (cont.).

Source

Emission

Control

Device CASRNb Pollutant

Emission

Factor

Emission

Factor Unitsc

EMISSION

FACTOR

RATING

10.6.4-22 EMISSION FACTORS 9/2002

Fiberboard board

dryer, indirect

heated, 6-12%

asphalt binder

(heated zones),

softwood

(SCC 3-07-015-12)

None

75-07-0

67-64-1

107-02-8

80-56-8

50-00-0

67-56-1

108-95-2

THC as carbond

VOC as propanee

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl isobutyl ketone *

Methyl ethyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.11h

0.14h

BDL

BDL

BDL

0.0029h

0.0048h

0.0012h

0.014h

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.013h

BDL

0.026h

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0014h

BDL

BDL

BDL

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

D

E

E

E

E

E

E

E

E

a Factors represent uncontrolled emissions. SCC = Source Classification Code. * = hazardous air

pollutant. BDL = below test method detection limit; indicates that this pollutant has not been detected

in any test runs on this source. Reference 3 unless otherwise noted. See Table 10.6.4-10 for the

hardwood and softwood species commonly used in the production of hardboard, fiberboard, and other

composite wood products. Note: emission factors in table represent averages of data sets. The

data spreadsheets, which may be more useful for specific applications, are available on EPA’s

TTN website at: http://www.epa.gov/ttn/chief/.

b CASRN = Chemical Abstracts Service Registry Number.

c Emission factor units: pounds of pollutant per oven-dried ton of wood material (lb/ODT); one lb/ODT

= 0.5 kg/Mg (oven-dried); pounds of pollutant per thousand square feet of 1/2-inch thick panel

(lb/MSF 1/2); one lb/MSF 1/2 = 0.38 kg/m3; pounds of pollutant per thousand square feet of 1/8-inch

thick panel (lb/MSF 1/8); one lb/MSF 1/8 = 1.54 kg/m3.

d THC as carbon = total hydrocarbon measurements using EPA Method 25A.
Table 10.6.4-3 (cont.).

9/2002 Wood Products Industry 10.6.4-23

e VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

f Reference 2.

g Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.

h Emission factors apply only to the heated zones of the dryer; the cooling sections also have emissions

but data were not available for cooling section emissions.
10.6.4-24 EMISSION FACTORS 9/2002

Table 10.6.4-4. EMISSION FACTORS FOR HARDBOARD PRESSES--PARTICULATE MATTERa

Sourcec

Emission

Control

Device

Filterableb

Condensibled

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Hardboard hot

press, PF resin

(SCC 3-07-014-40)

Uncontrolled 0.14 E 0.086 E 0.12 E

a Emission factor units are pounds of pollutant per thousand square feet of 1/8-inch thick panel

(lb/MSF 1/8). One lb/MSF 1/8 = 1.54 kg/m3. Factors represent uncontrolled emissions. SCC =

Source Classification Code. Reference 4. Note: emission factors in table represent averages of

data sets. The data spreadsheets, which may be more useful for specific applications, are

available on EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c PF = phenol formaldehyde.

d Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

Table 10.6.4-5. EMISSION FACTORS FOR HARDBOARD PRESSES--NOx, CO, AND CO2

a

Sourceb

Emission

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hardboard hot press,

PF resin

(SCC 3-07-014-40)

Uncontrolled ND ND ND

a Emission factor units are pounds of pollutant per thousand square feet of 1/8-inch thick panel

(lb/MSF 1/8). One lb/MSF 1/8 = 1.54 kg/m3. Factors represent uncontrolled emissions. SCC =

Source Classification Code. ND = no data available. Note: emission factors in table represent

averages of data sets. The data spreadsheets, which may be more useful for specific applications,

are available on EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b PF = phenol formaldehyde.
9/2002 Wood Products Industry 10.6.4-25

Table 10.6.4-6. EMISSION FACTORS FOR HARDBOARD PRESSES--ORGANICSa

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

Hardboard hot press,

PF resin

(SCC 3-07-014-40)

Uncontrolled THC as carbone 0.42 D

VOC as propanef 0.52 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

2,4-Dimethylbenzaldehyde BDL

3-Carene BDL

75-07-0 Acetaldehyde * 0.016 D

67-64-1 Acetone 0.0055g D

Acrolein * BDL

Alpha-pinene BDL

Benzaldehyde BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Butyraldehyde BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Crotonaldehyde BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.014 D

Hexaldehyde BDL

Isovaleraldehyde BDL

Limonene BDL

67-56-1 Methanol * 0.24g D

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

1330-20-7 m,p-Xylene * 0.0053 D

o-,m-,p-Tolualdehyde BDL

95-47-6 o-Xylene * 0.0036 D

p-Cymene BDL

p-Mentha-1,5-diene BDL

108-95-2 Phenol * 0.010 D

Propionaldehyde * BDL

Styrene * BDL

108-88-3 Toluene * 0.0011 D

Valeraldehyde BDL
Table 10.6.4-6 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

10.6.4-26 EMISSION FACTORS 9/2002

Hardboard hot press,

PF resin

(SCC 3-07-014-40)

Scrubber THC as carbone 0.043 E

VOC as propanef 0.052 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

75-07-0 Acetaldehyde * 0.0033 E

67-64-1 Acetone 0.0039 E

Acrolein * BDL

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-00 Formaldehyde * 0.0034 E

Limonene BDL

67-56-1 Methanol * 0.15 E

Methyl ethyl ketone * BDL

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

Phenol * BDL

Propionaldehyde * BDL

Styrene * BDL

Toluene * BDL
Table 10.6.4-6 (cont.).

Sourceb

Emission

Control

Devicec CASRNd Pollutant

Emission

Factor

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-27

Hardboard hot press,

linseed oil binder

(SCC 3-07-014-42)

Uncontrolled THC as carbone 0.58 E

VOC as propanef 0.71 E

1,2-Dichloroethane * BDL

1,2,4-Trichlorobenzene * BDL

3-Carene BDL

75-070 Acetaldehyde * 0.036 E

67-64-1 Acetone 0.015 E

107-02-8 Acrolein * 0.0057 E

Alpha-pinene BDL

Benzene * BDL

Beta-pinene BDL

Bromomethane * BDL

Camphene BDL

Chloroethane * BDL

Chloroethene * BDL

Cis-1,2-dichloroethylene BDL

Cumene * BDL

50-00-0 Formaldehyde * 0.018 E

Limonene BDL

67-56-1 Methanol * 0.093 E

78-93-3 Methyl ethyl ketone * 0.0045 E

Methyl isobutyl ketone * BDL

Methylene chloride * BDL

m,p-Xylene * BDL

o-Xylene * BDL

p-Cymene BDL

p-Mentha-1,5-diene BDL

108-95-2 Phenol * 0.0039 E

123-38-6 Propionaldehyde * 0.031 E

Styrene * BDL

Toluene * BDL

a Emission factor units are pounds of pollutant per thousand square feet of 1/8-inch thick panel

(lb/MSF 1/8). One lb/MSF 1/8 = 1.54 kg/m3. Factors represent uncontrolled emissions unless

otherwise noted. SCC = Source Classification Code. * = hazardous air pollutant. BDL = below test

method detection limit; indicates that this pollutant has not been detected in any test runs on this

source. Reference 3 unless otherwise noted. Note: emission factors in table represent averages of

data sets. The data spreadsheets, which may be more useful for specific applications, are

available on EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b PF = phenol formaldehyde.

c Emission control device: scrubber consists of a water quench, followed by a water tray tower,

followed by a high-energy venturi scrubber with a 49-inch pressure drop, followed by a chevron

demister.
Table 10.6.4-6 (cont.).

10.6.4-28 EMISSION FACTORS 9/2002

d CASRN = Chemical Abstracts Service Registry Number.

e THC as carbon = total hydrocarbon measurements using EPA Method 25A.

f VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value

of zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

g References 3 and 4.
9/2002 Wood Products Industry 10.6.4-29

Table 10.6.4-7. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD MISCELLANEOUS

SOURCES–PARTICULATE MATTERa

Source

Emission

Control

Device

Filterableb

Condensiblec

EMISSION

FACTOR

PM RATING

EMISSION

FACTOR

RATING PM-10

EMISSION

FACTOR

RATING

Hardboard sander

(SCC 3-07-014-80)

Fabric filter 0.030 E ND ND

Log storage

(SCC 3-07-008-95)

Uncontrolled ND ND ND

Debarking

(SCC 3-07-008-01)

Uncontrolled ND ND ND

Log cutting

(SCC 3-07-008-02)

Uncontrolled ND ND ND

Log chipping

(SCC 3-07-014-82)

Uncontrolled ND ND ND

Chip storage

(SCC 3-07-008-21)

Uncontrolled ND ND ND

a Emission factor units are pounds of pollutant per thousand square feet of 1/8-inch thick panel

(lb/MSF 1/8). One lb/MSF 1/8 = 1.54 kg/m3. SCC = Source Classification Code. ND = no data

available. Reference 4.

b Filterable PM is that PM collected on or prior to the filter of an EPA Method 5 (or equivalent)

sampling train. Filterable PM-10 is that PM collected on the filter, or in the sample line between the

cyclone and filter of an EPA Method 201 or 201A sampling train.

c Condensible PM is that PM collected in the impinger portion of a PM sampling train (EPA Method

202).

Table 10.6.4-8. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD MISCELLANEOUS

SOURCES--NOx, CO, AND CO2

a

Source

Emission

Control

Device NOx

EMISSION

FACTOR

RATING CO

EMISSION

FACTOR

RATING CO2

EMISSION

FACTOR

RATING

Hardboard

humidification kiln,

indirect heated

(SCC 3-07-014-30)

Uncontrolled 0.0028 E 0.16 E ND

a Emission factor units are pounds of pollutant per thousand square feet of 1/8-inch thick panel

(lb/MSF 1/8). One lb/MSF 1/8 = 1.54 kg/m3. SCC = Source Classification Code. ND = no data

available. Reference 2.
10.6.4-30 EMISSION FACTORS 9/2002

Table 10.6.4-9. EMISSION FACTORS FOR HARDBOARD AND FIBERBOARD MISCELLANEOUS

SOURCES--ORGANICSa

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

Log storage

(SCC 3-07-008-95)

Uncontrolled THC, VOC ND

Debarking

(SCC 3-07-008-01)

Uncontrolled THC, VOC ND

Log cutting

(SCC 3-07-008-02)

Uncontrolled THC, VOC ND

Chip storage

(SCC 3-07-008-21)

Uncontrolled THC, VOC ND

Hardboard log

chipper, hardwood

(SCC 3-07-014-82)

None

67-56-1

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.0041

0.0050

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0010

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

lb/ODT

lb/ODT

lb/ODT

E

E

E
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-31

Hardboard

pressurized digester/

refiner, hardwood

(SCC 3-07-014-84)

None

75-07-0

67-64-1

107-02-8

80-56-8

127-91-3

50-00-0

138-86-3

67-56-1

78-93-3

108-10-1

108-95-2

123-38-6

100-42-5

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.40

0.49

BDL

BDL

BDL

0.030

0.0042

0.0024

0.0039

BDL

0.0063

BDL

BDL

BDL

BDL

BDL

BDL

0.0045

0.0026

0.35

0.00025

0.00024

BDL

BDL

BDL

BDL

BDL

0.0012

0.00091

0.00016

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

E

E

E

E

E

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

10.6.4-32 EMISSION FACTORS 9/2002

Hardboard former

vacuum system, wet,

PF resin

(SCC 3-07-014-86)

None

75-07-0

67-64-1

50-00-0

67-56-1

78-93-3

108-10-1

108-95-2

123-38-6

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

BDL

BDL

BDL

0.0058

0.0032

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.00026

BDL

0.054

0.00030

0.00023

BDL

BDL

BDL

0.00071

0.00021

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

D

D

D

D

D

D

D

D
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-33

Fiberboard

atmospheric refiner

and dump chest,

softwood

(SCC 3-07-015-30)

None

75-07-0

67-64-1

107-02-8

80-56-8

127-91-3

98-82-8

50-00-0

138-86-3

67-56-1

78-93-3

123-38-6

108-88-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.79

0.96

BDL

BDL

BDL

0.0027

0.0039

0.00030

0.72

BDL

0.099

BDL

BDL

BDL

BDL

BDL

0.0034

0.00061

0.017

0.0084

0.00021

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.00026

BDL

0.00029

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

E

E

E

E

E

E

E

E

E

E

E

E

E

E
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

10.6.4-34 EMISSION FACTORS 9/2002

Fiberboard washer,

softwood

(SCC 3-07-015-40)

None

75-07-0

67-64-1

50-00-0

67-56-1

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.19

0.23

BDL

BDL

BDL

0.015

0.0047

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0026

BDL

0.13

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

lb/ODT

E

E

E

E

E

E
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

9/2002 Wood Products Industry 10.6.4-35

Fiberboard former

vacuum system, wet,

6-12% asphalt

(SCC 3-07-015-50)

None

75-07-0

67-64-1

50-00-0

67-56-1

108-88-3

THC as carbone

VOC as propanef

1,2-Dichloroethane *

1,2,4-Trichlorobenzene *

3-Carene

Acetaldehyde *

Acetone

Acrolein *

Alpha-pinene

Benzene *

Beta-pinene

Bromomethane *

Camphene

Chloroethane *

Chloroethene *

Cis-1,2-dichloroethylene

Cumene *

Formaldehyde *

Limonene

Methanol *

Methyl ethyl ketone *

Methyl isobutyl ketone *

Methylene chloride *

m,p-Xylene *

o-Xylene *

p-Cymene

p-Mentha-1,5-diene

Phenol *

Propionaldehyde *

Styrene *

Toluene *

0.15

0.17

BDL

BDL

BDL

0.0075

0.014

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0036

BDL

0.014

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

BDL

0.0023

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

lb/MSF 1/2

E

E

E

E

E

E

E
Table 10.6.4-9 (cont.).

Source

Emission

Control

Deviceb CASRNc Pollutant

Emission

Factor

Emission

Factor

Unitsd

EMISSION

FACTOR

RATING

10.6.4-36 EMISSION FACTORS 9/2002

Hardboard

humidification kiln,

indirect heated

(SCC 3-07-014-30)

None

75-07-0

67-64-1

107-02-8

71-43-2

75-00-3

74-87-3

100-41-4

50-00-0

66-25-1

78-93-3

1319-77-3

95-48-7

108-95-2

123-38-6

108-88-3

1330-20-7

THC as carbone

VOC as propanef

2,4-Dimethylbenzaldehyde

Acetaldehyde *

Acetone

Acrolein *

Benzaldehyde

Benzene *

Benzo(a)pyrene

Bromomethane *

Butyraldehyde

Chloroethane *

Chloromethane *

Crotonaldehyde

Ethanol

Ethylbenzene *

Formaldehyde * 

Hexaldehyde

Isobutanol

Isovaleraldehyde

Methanol *

Methyl ethyl ketone *

Methyl propyl ketone *

Methylene chloride *

m,p-Cresol *

Naphthalene *

o-Cresol *

o-,m-,p-Tolualdehyde

Phenol *

Propanol

Propionaldehyde *

Pyridine

Styrene *

Toluene *

Trichlorofluoromethane

Valeraldehyde

Xylenes *

0.62g

0.76

BDL

0.0018g

0.0038g

0.0087g,h

BDL

6.2E-06g

BDL

BDL

BDL

0.000014g

0.00012g

BDL

BDL

0.000032g

0.0010g,h

0.011g,h

BDL

BDL

BDL

0.0014g

BDL

BDL

0.00033g

BDL

0.00021g

BDL

0.00057g

BDL

0.0077g

BDL

BDL

0.000034g

BDL

BDL

0.000042g

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

lb/MSF 1/8

E

E

E

D

E

E

E

E

E

E

E

E

E

E

E

E

E

E

a Factors represent uncontrolled emissions unless otherwise noted. SCC = Source Classification Code. * =

hazardous air pollutant. BDL = below test method detection limit; indicates that this pollutant has not

been detected in any test runs on this source. Reference 3 unless otherwise noted. Note: emission

factors in table represent averages of data sets. The data spreadsheets, which may be more useful

for specific applications, are available on EPA’s TTN website at: http://www.epa.gov/ttn/chief/.

b Fabric filters (baghouses) are considered no control for organic pollutants. c CASRN = Chemical Abstracts Service Registry Number.
Table 10.6.4-9 (cont.).

9/2002 Wood Products Industry 10.6.4-37

d Emission factor units: pounds of pollutant per oven-dried ton of wood material (lb/ODT); one lb/ODT =

0.5 kg/Mg (oven-dried); pounds of pollutant per thousand square feet of 1/2-inch thick panel

(lb/MSF 1/2); one lb/MSF 1/2 = 0.38 kg/m3; pounds of pollutant per thousand square feet of 1/8-inch

thick panel (lb/MSF 1/8); one lb/MSF 1/8 = 1.54 kg/m3. e THC as carbon = total hydrocarbon measurements using EPA Method 25A.

f VOC as propane = (1.22 × THC) + formaldehyde - (acetone + methane + methylene chloride); a value of

zero is inserted in the equation for the specified compounds where no emission factor is available, or

where the emission factor is reported only as “BDL”.

g Reference 2.

h Based on M0011 data only; suspected to be biased low due to poor collection efficiency or analytical

problems.
10.6.4-38 EMISSION FACTORS 9/2002

Table 10.6.4-10. WOOD SPECIES COMMONLY USED IN 

COMPOSITE WOOD PRODUCTS MANUFACTURING a

Wood product AP-42 section Hardwood species Softwood species

Plywood 10.5 Oak, cherry, poplar, maple,

larch

Firs, pines

Oriented strandboard 10.6-1 Aspen Pines, firs, spruce

Particleboard 10.6-2 Aspen, oak Pines, firs

Medium density

fiberboard

10.6-3 Gum, alder, hickory Pines, firs

Hardboard/fiberboard 10.6-4 Aspen, birch, beech, oak, maple Pines

Engineered wood products 10.9 Aspen, birch, poplar Pines, firs,

hemlock

a Reference 5.

References For Section 10.6.4

1. Background Information Document For Proposed Plywood And Composite Wood Products

NESHAP, prepared for the U. S. Environmental Protection Agency, OAQPS, by Midwest

Research Institute, Cary, NC, September 2000.

2. Results Of The January 17-19, 1995 Source Emission Tests On The Dryer Stack, Dump Stack

And Humidification Kiln Stack At The Georgia Pacific Facility Located In Phillips, Wisconsin,

prepared for CH2M Hill, by PACE, Inc., Project No. 941228.401, March 2, 1995.

3. Volatile Organic Compound Emissions From Wood Products Manufacturing Facilities, Part VI -

Hardboard/Fiberboard, Technical Bulletin No. 773, National Council of the Paper Industry for

Air and Stream Improvement, Inc., Research Triangle Park, NC, 1999.

4. Title V Emissions Test Report, PM10, Particulate Matter, Condensible Particulate Matter,

Aldehydes/Ketones, Phenols, Methanol, Oxygen, Carbon Dioxide, Carbon Monoxide, Nitrogen

Oxides, And Cold Total Hydrocarbons From Process Stacks, Georgia Pacific Hardboard

Manufacturing Plant, North Little Rock, Arkansas, Test Dates September 26-29, 1995, prepared

for CH2M Hill and Georgia Pacific Corporation, by DEECO, Inc., Report No. 95-1200-A,

October 27, 1995.

5. Emission Factor Documentation For AP-42 Chapter 10, Wood Products Industry, prepared for

the U. S. Environmental Protection Agency, OAQPS/EFIG, by Midwest Research Institute, Cary,

NC, July 2003.