'e$qn ^ENVIRONMENT
Auto Refinishing Project
Spray Booth Filters:
The Key to Quality Jobs and
Clean Emissions
US. EPA
What Is EPA's Design for the
Environment (DfE) Automotive
Refinishing Partnership?
EPA's DfE Program forms
partnerships to reduce risk to people
and the environment through
pollution prevention. DfE has been working with the
automotive refinishing industry since 1997 to identify
and promote safer, cleaner, and more efficient
practices and technologies. The DfE team conducts
best practices workshops and site visits for collision
repair businesses and schools. A Best Practices
Outreach Kit with checklists, fact sheets, case
studies, health and safety information, and links to
numerous resources can be downloaded from the
DfE web site at http://www.epa.gov/dfe/pubs/
projects/auto.
The Key to Quality Jobs and Clean Emissions
Best practices can reduce emissions of hazardous air
pollutants during spraying of automotive paints.
Painters should be trained in the efficient use of high
volume low pressure (HVLP) or equivalent spray
guns and use paints that do not contain lead or
chromium pigments. All spray painting should be
conducted in a well-ventilated and well-maintained
spray booth. This fact sheet highlights key factors
regarding the need to use and maintain paint booth
filters to achieve a quality job and protect the painter,
others in the shop, and the environment.
Spray Booth Filters Impact the Job Quality
and the Environment
The efficiency of the spray
booth operation, as well as
the resulting quality of the
sprayed finish is affected
by both the intake and
exhaust filters (also known
as paint overspray
arresters). When the
intake and paint arrester
filters are well
maintained, the air flows
evenly through the spray
chamber and around the part or vehicle surface,
picking up the overspray and volatiles and promptly
removing them from the area.
Booth Floor With Dirty Filters
Photo provided courtesy of Air
Flow Technology, Inc.
If the spray booth intake or exhaust filters become
clogged with dust or oversprayed particles, the air
may not flow properly through the chamber. Instead
of sweeping over the coated surface and exiting,
small pockets of dust and overspray may re-circulate
within the booth and
affect the quality of
the finish. In
addition, flammable
or explosive
conditions may be
created if volatile
solvents collect
within the closed
space. Clogged
filters also cause the
booth fans to work
harder, decreasing
their efficiency and
life.
Note: Most filters do not
remove solvent vapors
from shop exhausts!
While the spray booth works to
remove harmful solvent vapors
from inside the shop, most
exhaust filters do NOT remove
these solvent vapors or volatile
organic compounds (VOCs)
from the exhaust emitted into
the air from the shop.
Consider switching to
waterborne paint products to
reduce VOCs!
Exhaust Filters or Paint Overspray Arresters
Booths use exhaust filters or paint overspray
arresters to decrease emissions from the shop by
capturing the oversprayed coating mist and particles
before that air is exhausted from the shop into the
environment. These filters are located at the opposite
end of the intake filters in crossdraft booths, and in or
near the floor of downdraft booths.
Paint overspray arresters come in a variety of shapes
and styles, including bulk and perforated rolls,
blankets, pre-cut pads, cubes and bags, self-
supported panels with internal frames, baffled panels,
and accordion-folded panels. Paint overspray
arresters can be constructed from various materials
including fiberglass, polyester, paper, cardboard,
styrene, or a combination of materials.
Spray Booth Exhaust Filters Pocket Cube Filter
Photos provided courtesy of Air Flow Technology, Inc.
Revised May 2008
www.epa.gov/dfe
EPA 744-F-08-001
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Spray booth exhaust filters are typically capable of
removing between 90% to more than 99% of the
atomized automotive coating mists and particles that
are contained in the spray booth exhaust stream, thus
reducing the shop's emissions of potentially
hazardous paint materials into the air. These
materials may otherwise settle out of the air and fall
into neighboring properties and water sources.
Alert! New EPA Regulation
A new national standard now requires all shops that
spray coatings containing a targeted hazardous air
pollutant (HAP) to conduct spray operations in a booth
outfitted with an exhaust filter with a removal efficiency
of 98% or greater. Work with your spray booth
manufacturer or filter supplier to select the right filter for
your shop's filtration needs.
For specific details of the regulation, visit the EPA
website at http://www.epa.gov/fedrgstr/EPA-
AIR/2008/January/Day-09/a24718.htm
Intake Filters
Spray booths utilize intake filters to clean dirt and
particles from the air entering the chamber. Intake
filters are typically positioned in the doors or in panels
adjacent the doors at one end of a crossdraft booth,
and in the ceiling of downdraft booths. Downdraft
booths may also be outfitted with prefilters that
remove coarse dust upstream of the ceiling diffusion
filters, thus extending their life. These filters can
remove 75% to more than 99% of particles measuring
between 7 and 10 micrometers.
Proper Maintenance of Spray Booth Filters is
the Key!
Well-maintained filters ensure clean air enters the
booth and efficiently remove overspray particles and
mist from exhaust air.
In order to keep filters
in the best working
condition, it is
important to establish
the right change-out
schedule for your shop.
Readings from a
manometer or
magnehelic pressure
gauge should be used
to establish a change
out schedule for intake
and exhaust filters according to the booth
Remember!
Proper maintenance of your
filters not only ensures a
quality finish and efficient
operation of your spray booth,
it is a vital step in ensuring
that your spray painting
operation meets health and
safety standards required by
OSHA and NFPA regulations.
See OSHA 1910.107 and
NFPA 33 for more information
about spray booth safety
requirements.
manufacturer's specifications. If your booth does not
have a pressure gauge, you should establish a strict
maintenance schedule based upon the volume of
spray finishing taking place on a day-to-day basis. It
is typically recommended that ceiling filters be
changed at least twice a year. All other intake filters
should be changed once a month or as needed.
Different styles and brands of paint arresters will
reach their "target" reading and require replacement
at varying rates depending upon the paint type, booth
design, operator technique, fan speed, temperature,
spray equipment, etc.
Your spray booth manufacturer or filter supplier can
help you design an effective change-out schedule for
your shop - striking the right balance between your
filtration needs and cost efficiency in maintaining
optimum spray booth performance.
Worker Safety
When replacing used filters, workers should wear
appropriate personal protection: half-face, air-
purifying respirator with dual organic vapor and
dust/mist cartridges, gloves (e.g., nitrile gloves),
protective coveralls, and sleeve protectors.
Workers should wear a dust mask, gloves, and
coveralls to protect against dry paint and dust
particles that may break loose while handling dry
filters.
Proper Disposal of Waste Filters
Before disposing of waste filters, you must determine
whether the filters would be considered hazardous
waste. Consult with your jobber, filter supplier, and
local authorities for assistance in properly
characterizing and handling your waste filters.
For additional information,
visit the DfE Auto Refinishing
Partnership website at
http://www.epa.gov/dfe/
pubs/projects/auto
and the virtual auto body
shop on the CCAR-Greenlink
website at http://www.ccar-
qreenlink.orq/cshops.
Design for the Environment
Auto Refinish Project
www.epo.gov/dfe/pubs/proiec1s/auto/
Note: The mention or illustration of any product or company does not constitute an endorsement by the U.S.
Environmental Protection Agency.
EPA 744-F-08-001
www.epa.gov/dfe
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