United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-00/043 August 2000
Amy M. Marshall and Jennifer L. Fields
The report gives results of a study in
which wood furniture manufacturing fa-
cilities were identified that had con-
verted at least one of their primary
coating steps to low-volatile organic
compound (VOC)/hazardous air pollut-
ant (HAP) wood furniture coatings [high-
solids, waterborne, ultraviolet
(UV)-curable, or powder coatings].
Twenty-five case studies were devel-
oped, based on visits to the facilities
and discussions with plant personnel.
The case studies identify:
• Products manufactured,
• Types of low-VOC/HAP coatings
implemented,
• Equipment and process changes
required,
• Problems encountered during the
conversions,
• Advantages/disadvantages of the
low-VOC/HAP coatings,
• Customer feedback,
• Costs associated with conversions,
and
• Emissions and waste reductions.
General information about the wood
furniture manufacturing industry's typi-
cal emissions and applicable regula-
tions also is provided in the report. Each
coating technology is discussed indi-
vidually and facilities' experiences with
the low-VOC/HAP coatings studied are
summarized. The main goals of the
study were to demonstrate that low-
VOC/HAP coatings can be used suc-
cessfully by some wood furniture
manufacturers and to provide a re-
source to assist other manufacturers
in converting to low-VOC/HAP coatings.
This Project Summary was developed
by the National Risk Management Re-
search Laboratory's Air Pollution Pre-
vention and Control Division, Research
Triangle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
Many wood furniture manufacturing fa-
cilities are subject to surface coating regu-
lations that require them to use finishes
with low-volatile organic compound (VOC)
or hazardous air pollutant (HAP) contents.
However, moving away from the conven-
tional, solvent-borne, nitrocellulose-based
finishes that have been used for many
years concerns some wood furniture
manufacturers. Each alternative to tradi-
tional solvent-borne coating systems
raises different concerns (e.g., quality and
appearance of final product, changes to
plant operations, and cost). To address
these concerns, the U. S. Environmental
Protection Agency (EPA) initiated a coop-
erative agreement with Midwest Research
Institute (MR!) to find facilities that were
using low-emitting coatings successfully
and to provide information on their expe-
riences to the industry. The low-VOC/HAP
coatings studied were waterborne, ultra-
violet (UV)-cured, high-solids, and pow-
der coatings. Table 1 summarizes the
potential advantages and disadvantages
associated with each of the four types of
low-VOC/HAP wood coating technologies
studied.
The primary goals of the study were to
demonstrate that low-VOC/HAP coatings
can be used successfully by wood furni-
ture manufacturing facilities and to pro-
vide a resource to assist other wood
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Table 1. Advantages and Disadvantages of Low-VOC/HAP Coatings
Advantages
Disadvantages
High-Solids Coatings
High solids, better coverage
Lower VOC/HAP content than
traditional coatings
Low capital cost to change
Little or no equipment changes
necessary
Easy operator transition
Still use organic solvent
May have to heat lines to reduce viscosity
Flammability issues
Waterborne Coatings
High solids, better coverage
Low VOC/HAP content
Lower fire risks, no in-house storage
requirements
Hard finish
Low capital cost to change
Can clean equipment with water
Less toxic coatings, no smell
May have longer dry time or require ovens
May not produce desired appearance
Need to replace application equipment with stainless
steel or plastic
Do not re-wet after they have dried like nitrocellulose
coatings do
UV-Cured Coatings
Very high solids, little or no solvent
Low or no VOC/HAP content
Very durable finish
Cures in seconds, no dry time
Automated line (labor saver)
High capital cost to convert
Difficult to apply to three-dimensional pieces
Rework difficult
Safety considerations with coatings and UV light
Powder Coatings
100% solids, no solvent
No VOC/HAP content
Recycle overspray
Very durable finish, only one coat
necessary
Automated line
Short cure time
Easy to clean equipment
Limited application in wood finishing
Best for engineered wood substrates
High capital cost to convert
furniture manufacturing facilities in con-
verting to low-VOC/HAP coatings. Facili-
ties were identified that had converted
one or more of their primary coating steps
to low-VOC/HAP coatings and wanted to
participate in this study. Information was
gathered using Internet searches, trade
publications, trade associations, state
agency personnel, technical assistance
providers, and coating suppliers. Facility
personnel were contacted by phone and,
in most cases, a site visit was conducted.
They were then given the opportunity to
review and comment on the case study
writeup for their facility before it was final-
ized.
Emissions in the Wood
Furniture Industry
There are many sources of VOC/HAP
emissions in the wood furniture industry.
The primary emission sources include:
• Finishing (spray booths, flashoff ar-
eas, ovens),
• Cleaning,
• Mixing,
• Touch-up and repair, and
• Gluing.
Finishing
Finishing operations typically account
for the largest portion of the facility-wide
VOC/HAP emissions. Wood furniture fin-
ishing consists of the application of a se-
ries of color coats and/or clear coats. The
furniture may be sanded, rubbed, or pol-
ished between coats, and may pass
through drying ovens or flashoff areas.
Typical pollutants emitted include
alcohols, methyl ethyl ketone (MEK), me-
thyl isobutyl ketone (MIBK), toluene, and
xylene. Acetone, although not considered
a VOC or HAP, also is emitted by the
industry in large quantities. It is assumed
that all solvent in the applied finish evapo-
rates during the finishing process, either
as the coating is applied or as it dries or
cures.
Cleaning
Emissions of VOCs/HAPs are gener-
ated from cleaning operations if an or-
ganic solvent is used to clean application
equipment, spray booths, or other equip-
ment. Organic solvent is necessary to
clean equipment that has been used to
apply solvent-borne and UV-cured coat-
ings, while hot water can be used to clean
equipment that has been used to apply
waterborne coatings. Roll coaters are
cleaned by soaking the roll in either wa-
ter or solvent, depending on the type of
coating being used. A spray gun usually
is cleaned by soaking it in solvent or
sending solvent or water through it and
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atomizing the liquid into the booth venti-
lation system. This practice is common
unless a dedicated coating supply line
and spray gun are used for each color or
type of coating. Using dedicated lines pro-
duces a significant reduction in cleaning
emissions. If a facility is using powder
coatings, there are little or no emissions
of VOC from cleaning, since the equip-
ment can be wiped down with a cloth or
blown out with air.
Mixing and Touch-up/Repair
Some VOC emissions may occur dur-
ing mixing operations if volatile materials,
such as thinning solvent, are used or if
material leaks or is spilled. However, most
facilities purchase their finishing materi-
als ready to use (no thinning is required).
Touch-up and repair operations are a
source of VOC emissions if solvent is
used to strip a piece of furniture or per-
form spot rework.
Gluing
Gluing operations can potentially be
as large a source of emissions as finish-
ing operations, depending on the type of
glue used. In the past, glues containing
methylene chloride were widely used and
could account for a significant portion of
a facility's HAP emissions. In recent years,
wood furniture plants have transitioned to
waterborne, hot melt, or low-VOC/HAP
adhesives as alternatives.
Wood Furniture Industry
Regulatory Requirements
In 1995, the EPA promulgated National
Emission Standards for Hazardous Air
Pollutants (NESHAPs) for the wood furni-
ture manufacturing industry. With some
exceptions, the NESHAPs apply to wood
furniture manufacturing facilities that emit
10 tons or more per year of one HAP or
25 tons or more per year of any combina-
tion of HAPs. The NESHAPs require fa-
cilities to implement work practice
standards and provide pollution preven-
tion alternatives as compliance options.
Facilities can implement low-HAP coat-
ing and gluing technologies rather than
installing an air pollution control device.
For wood furniture manufacturing facili-
ties, implementing low-VOC/HAP coatings
often is the most cost-effective option.
However, many facilities subject to
NESHAPs simply reformulated their sol-
vent-borne coatings to include solvents
that are considered VOCs but not HAPs.
In 1996, the EPA issued a Control
Techniques Guideline (CTG) Document,
which outlined methods of reducing VOC
emissions from wood furniture finishing
operations. The CTG recommended the
use of waterborne topcoats or high-solids
sealers and topcoats as reasonably avail-
able control technology (RACT) for finish-
ing operations. States must implement
rules that require wood furniture manu-
facturing facilities in ozone nonattainment
areas to control VOC emissions to levels
at least as stringent as those recom-
mended in the CTG.
Case Studies
Twenty-five case studies were prepared
during this study for a variety of facilities,
products, and coating technologies. Fa-
cilities in 13 states were studied. Five
facilities were located in ozone
nonattainment areas. Visits were made to
23 of the 25 facilities. Facilities ranged in
size from 2 to 900 employees, with prod-
ucts ranging from coated panels used as
casegood components to high-end furni-
ture and cabinets.
Table 2 shows the distribution of the
facilities by product and coating type.
Many facilities use more than one type of
low-VOC/HAP coating technology, and
those facilities appear in more than one
category (e.g., one plant was using water-
borne, UV-cured, and powder coatings).
Nine of the facilities studied had con-
verted all of their coating steps to low-
VOC/HAP coatings.
Reasons for Converting
Coatings
The facilities cited several reasons for
switching to low-VOC/HAP coatings and
implementing other pollution prevention
measures:
• A desire to use materials that are
less hazardous,
• A commitment to the environment,
• To avoid being subject to the
NESHAPs for wood furniture manu-
facturing,
• In anticipation of having to comply
with the wood furniture NESHAPs,
• As part of an overall pollution pre-
vention program,
• A desire for a higher-quality finish,
• To lower emissions, and
• To increase production without in-
creasing emissions or exceeding per-
mit limits.
Emissions Reductions
Achieved
The facility-wide VOC emissions reduc-
tions achieved by implementing pollution
prevention measures (such as low-VOC
coatings) ranged from about 12 to 98%.
The costs incurred or saved in converting
to the new coating systems included capi-
tal costs, material costs, labor costs, and
energy costs. Facilities that converted to
high-solids or waterborne coatings typi-
cally experienced the lowest conversion
costs. Costs and cost savings for materi-
als, labor, and energy varied widely
among facilities.
Costs
Cost savings were incurred when fa-
cilities were able to reduce labor costs,
material usage, fire insurance, and per-
mit/waste disposal fees. Often, a cost sav-
ing was experienced even if the cost of
the coating increased, due to lower labor
costs, a more efficient application tech-
nique, or higher coating solids content.
Other Benefits
The facilities studied achieved benefits
in addition to reductions in cost and emis-
sions of VOCs/HAPs when they imple-
mented pollution prevention measures:
• Reduction or elimination of hazard-
ous waste,
• Reduction in wasted materials (e.g.,
coating, solvent, or wood),
• Reduction of fire risk,
• Improved working conditions,
• Enhanced company image,
• Improved coating performance, and
• Increased production capacity.
Table 2. Breakdown of Facilities Studied by Product and Coating Type
Low VOC/HAP
Coating
Technology
High-solids
Waterborne
UV-cured
Powder
Product Type
Residential
Furniture
3
7
2
0
Office/Institutional
Furniture
1
4
4
1
Cabinets or
Components
2
4
4
0
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Conclusion
The main goals of this study were to
demonstrate that low-VOC/HAP coatings
can be used successfully by some wood
furniture manufacturers and to provide a
resource to assist other manufacturers in
converting to low-VOC/HAP coatings. By
presenting pollution prevention case stud-
ies that apply to a variety of wood furni-
ture manufacturers and coating types,
these goals have been accomplished.
Each facility studied experienced numer-
ous benefits from converting to low-VOC/
HAP wood coatings, including emissions,
waste, and cost reductions, and quality
and safety improvements.
A. Marshall and J. Fields are with Midwest Research Institute, Cary, NC 27511.
Julian W. Jones is the EPA Project Officer (see below).
The complete report, entitled "Case Studies: Low-VOC/HAP Wood Furniture
Coatings," (Order No. PB2000-106 999; Cost $36.00, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: (703) 605-6000
(800) 553-6847 (U.S. only)
The EPA Project Officer can be contacted at:
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
CenterforEnvironmental Research Information
Cincinnati, OH 45268
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use
$300
EPA/600/SR-00/043
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