Breathing Easy... Ensuring Proper Ventilation of Paint Mixing Rooms In ...
Make-up air vents are located about 2 feet ... the room through the make-up air vents passes over the work bench and mixes with ...
Breathing Easy...
Ensuring Proper Ventilation of Paint
Mixing Rooms In Auto Refinish Shops
This fact sheet describes ways shop own-
The Auto Refinish Project
A
ers can improve ventilation in paint mixing
uto refinishers use many potentially
and cleanup rooms and discusses other steps
harmful chemicals when painting
to better protect workers during paint mixing
vehicles and auto parts. In particular,
operations.
shops use solvents, isocyanates, pigments,
and other additives in paints and coatings
that can present serious risks to human
health and the environment. Isocyanates, for
Ventilation Systems—
example, are the leading cause of occupa- The Basics
W
tional asthma in the United States. ithout proper ventilation, paint
To help protect auto refinish workers and mixing and cleanup rooms can be
www.epa.gov/dfe/projects/auto unhealthy. Paints, solvents, and
neighborhoods from these hazardous chemi-
cals, the U.S. Environmental Protection reducers all generate hazardous vapors that
Agency (EPA) launched the Auto Refinish can build up and remain in a room.
Project, part of EPA‘s Design for the Ventilation systems are needed to remove
Design for the
Environment (DfE) Program. Through this these vapors and provide a healthy working
Environment
environment.
project, EPA has formed partnerships with
Auto Refinish Project
Philadelphia-area auto refinish shops to deter- There are two basic types of ventila-
In its Auto Refinish Project,
U.S. EPA’s Design for the mine which tasks pose the greatest health tion–general exhaust ventilation and local
Environment (DfE) Program threats and which procedures and equipment exhaust ventilation.
works with auto refinishers to protect workers best. In many cases, these General exhaust ventilation systems
identify and encourage safer, typically consist of an exhaust fan, mounted
cleaner, and more efficient procedures and equipment also increase shop
practices and technologies. efficiency and help save money on shop in the ceiling or wall, that pulls air out of the
EPA’s project team has uncov materials and waste disposal fees. workroom and discharges it outdoors.
ered many examples of health Replacement air is brought into the work
and safety improvements that area by either natural means, such as win-
increase efficiency and can
help shops save money. Reducing Risks During dows and vents, or by a more sophisticated
setup that includes a separate make-up air
If you’re interested in partici
pating or would like to learn Paint Mixing and fan, duct work, and air registers that provide
more about this project,
Cleanup clean air to the work space. General exhaust
S
please write Mary Cushmac
at [email protected] or pray painting operations may present ventilation is also known as "dilution venti-
David Di Fiore at difiore.david the greatest potential risks to auto lation" because it dilutes vapors by mixing
@epa.gov, or visit the DfE refinishers. Many shops have them with cleaner room air.
Web site at . addressed this risk through the use of venti- Since they do not immediately remove
For a virtual auto body lated spray booths, respirators, gloves, and the vapors from the work space, general
shop experience, filled with coveralls when spray painting. exhaust systems are not recommended as the
helpful health, safety, and effi Two operations–paint mixing and sole source of ventilation when hazardous
ciency information, visit
. The virtual auto are considering safety measures. Many work- provide a path for make-up air to enter the
body shop is a joint product ers perform paint mixing and cleanup in workroom; however, fire codes typically
of DfE and the Coordinating small, enclosed rooms with little or no venti- require that mixing room doors that open
Committee for Auto Repair
(CCAR). lation or with ventilation that works improp- into other areas of the shop remain closed
erly, often increasing worker exposure. when not in use.)
Common Paint Mixing Room Ventilation Mistakes
Does your ventilation system provide workers with enough pro
tection? Consider the following situations, which describe venti
lation scenarios found in many auto refinish shops: Paint/solvent vapors
Scenario: An exhaust fan is installed in the ceiling of a small drawn through worker's
Make-up breathing zone
paint mixing room, directly above the paint mixing air inlet
bench.
Issue: The fan is installed too far from the mixing opera
tions to capture the vapors and, thus, is allowing
them to mix with general room air before being Exhaust vent
exhausted. In addition, many of the hazardous
vapors emitted in the paint mixing room are Mixing
Bench
heavier than air and tend to collect at floor level.
Exhaust fans at the ceiling level do little to capture
and remove these low-lying vapors.
Scenario: An exhaust fan is installed in a paint mixing room at Figure 1. Poor Ventilation Design
floor level on the wall just opposite from the work
bench. Make-up air vents are located about 2 feet
above the surface of the work bench, directly in front of the workers’ faces. (See Figure 1.)
Issue: While this system provides for the removal of low-lying vapors, it creates a new problem. The air supplied to
the room through the make-up air vents passes over the work bench and mixes with solvent vapors emitted
during the mixing process. Because the exhaust fan is on the opposite wall, behind the workers, the con
taminated air travels past the workers’ faces before being exhausted from the room.
Local exhaust ventilation systems remove chemicals and With a combined system, it is only necessary to turn on the
other contaminants at their source. These systems are recom- local exhaust ventilation during actual mixing or cleaning
mended for controlling hazardous vapors because, if designed operations. The general exhaust ventilation, however, should
properly, they remove the vapors before workers are exposed remain on throughout the workday to maintain constant air
to them. Local exhaust ventilation systems always consists of circulation in the room. A combined system actually can help
three basic components: reduce energy costs because the local exhaust ventilation sys-
• A hood (exhaust vent or special duct end) installed as close tem, which operates for only a small portion of the work day,
as possible to where work is performed, to capture the can remove the majority of the vapors from the room while
vapors; only exhausting a small amount of air. This lowers the concen-
• Ductwork to transport the vapors from the hood to outside tration of vapors in the room and allows you to operate the
the building; and general ventilation system at a lower flow rate, thus reducing
• A fan located downstream of the hood to draw air away the amount of heated (or air-conditioned) air exhausted from
from the work area, through the hood and ductwork, and the building throughout the day.
discharge it from the building.
Gun Paint
Combination Systems: An Washer Waste
Drum
Effective Solution Clean
T
Solvent Exhaust Vent
he most effective way to ventilate your paint mixing Drum
rooms is to use both local and general exhaust ventila-
tion systems in combination. A local exhaust system Make-up
installed at the work bench as close to the mixing operation as Mixing
air inlet
possible will capture most hazardous vapors before they can Bench
escape into the room air and be inhaled by workers. A general
ventilation system for the room with floor level exhaust vents
Door
will remove low-lying vapors that are not captured by the
local exhaust system or are generated from other sources of
vapor in the room, including trash cans containing solvent- Figure 2. Top view of room—
laden rags; gun cleaners or other equipment; and open solvent, Locate exhaust vent near vapor sources
paint, and waste containers.
• Position exhaust vents as close to the source of haz-
ardous vapors as possible to reduce the spread of
Make-up
vapors in the room (see Figure 2).
air inlet • Situate exhaust vents and sources of make-up air so that
Paint/solvent vapors hazardous vapors are not drawn past the worker on the
drawn away from
worker's breathing zone way to the exhaust vent (see Figure 3).
• Ensure continual movement of air within the paint mixing
room to prevent hazardous vapors from accumulating.
• Conserve energy by installing a fan that operates at two
speeds: a higher speed for greater air movement when
Exhaust
workers are in the area, and a lower speed for reduced air
vent flow when workers are not present.
• Place exhaust vents at or near floor level to remove low-
lying vapors.
Figure 3. Draw vapors away • Locate exhaust vents and sources of make-up air on oppo-
from workers breathing zone site sides of the room to ensure that air flows through the
entire room (see Figure 4).
Make Informed Decisions
A
properly designed ventilation system can make the
mixing room and shop operations cleaner, safer, and
Baffles
more efficient. An improperly designed system, how-
ever, will do little to improve current workplace conditions or Exhaust Slots
protect workers. For this reason, it is important to make sure
that the system is designed and installed by properly trained
individuals, such as a qualified ventilation contractor or an
industrial hygienist. As an alternative, prefabricated paint mix-
ing rooms are currently on the market and typically provide
spill protection, explosion-proof electrical installation, and Mixing Bench
general ventilation.
Tips to Consider Figure 5. Local exhaust ventilation
General Ventilation
When considering general exhaust ventilation systems for
your paint mixing room, it is important to: Local Ventilation
Local exhaust systems can be more expensive to install initial-
ly, but they offer greater worker protection. In addition, oper-
ating costs are generally reduced by allowing for a reduced
general exhaust flow rate. The following considerations should
be taken into account when installing a local exhaust system
Exhaust Vent in your paint mixing room:
• The fan must be sized correctly to move the required
amount of air.
Mixing
Bench Make-up • The exhaust hood or vent should be located within 1 to 2
air inlet feet of the mixing operation to effectively capture vapors.
• Air velocity at the exhaust hood or vent must be strong
enough to overcome potential cross drafts.
Door
• A series of slot exhausts located at the rear of the paint
mixing table at about the level that work occurs will most
effectively capture vapors generated during paint mixing
Figure 4. Top view of room—Locate operations (see Figure 5).
make-up air inlet opposite from exhaust vent • The use of baffles or other types of enclosures at the sides of
the mixing table will help reduce cross drafts and improve
the system‘s ability to capture vapors (see Figure 5).
• Use air-purifying respirators and create a respiratory pro-
Special Design Considerations
N
tection program, including fit testing and cartridge
o matter what type of ventilation system you
change-out schedules. This is especially important when
choose, keep in mind that the vapors produced in
ventilation does not adequately reduce harmful vapors.
paint mixing rooms are extremely flammable and
• Always wear chemical-protective gloves during paint
can produce explosive environments. For this reason, all
mixing and gun cleaning activities. Note: latex gloves
electrical equipment that you place or install in this room,
typically do not hold up well against solvents and iso-
including ventilation fans, wiring, and switches, must be
cyanates and can cause allergic reactions. Nitrite gloves
specifically designed and approved for use in explosive
would be a more protective choice. Talk to your paint
atmospheres. Ventilation equipment manufacturers should
distributor or equipment supplier to determine the most
be able to tell you what types of environments their equip-
appropriate types of gloves for your operations.
ment can be used in. In addition, electrical equipment
• Close all containers of solvents, paints, and reducers
approved for use in flammable or explosive environments
immediately after use to minimize vapor emissions. This
should bear appropriate labels. For more information about
not only prevents workers from breathing hazardous
applicable electrical requirements, contact your local Fire
vapors, but also saves money by reducing the amount of
Marshall.
refinishing and cleaning products lost through evaporation.
• Fit all waste drums with funnel lids. Keep the lids closed
Other Safety Considerations when you are not using them. Most safety product dis-
P
roper ventilation systems are a vital part of ensuring a tributors sell funnel lids that allow for easy drum access
safe work environment. Nevertheless, workers should when transferring solvent wastes.
take additional precautions when mixing paint and • Keep tight-fitting lids on all trash containers.
cleaning up. Here are some steps workers can take every • Clean up all spills immediately. Allowing spilled materials
day to further reduce risks to their health when they perform to simply evaporate from the work surface can greatly
these operations: increase the amount of hazardous vapors present in the air.
Draft
744-F-02-008
May 2002
