Automotive Fluids
Auto Body Shops
Pollution Prevention Guide
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Solvents
| Antifreeze | Aerosols
Automotive fluids, such as antifreeze and cleaning solvents, can be one of
the largest waste streams generated in an auto body shop. This section will
discuss pollution prevention options for cleaning solvents, antifreeze, and
aerosol sprays.
Cleaning
Solvents
Cleaning solvents are often the largest automotive fluid waste generated in
an auto body shop. Automotive cleaning solvents typically contain chemicals
such as methylene chloride, toluene, and xylene. Over-exposure to such solvents
and their vapors can lead to cancer, nervous system damage, or skin disorders.
Waste solvents are most often regulated as hazardous wastes because they may
be listed specifically in the regulations, ignitable, or corrosive. The main
methods of preventing pollution in parts washing include:
- Selecting less hazardous cleaning methods
- Substituting less hazardous solvents
- Extending the life of the solvent used
Less Hazardous Cleaning Methods
There are a number of cleaning methods that can be selected to
help reduce your exposure to chemicals, maximize solvent life, and reduce the
amount of solvents used. Three such alternatives are discussed below.
Mechanical Cleaning - Mechanically cleaning parts can be
as simple as cleaning dirt and grit off parts with a wire brush before placing
them in the solvent sink or parts washer. More elaborate approaches include
abrasive material, such as sand or plastic pellets, to "blast" away dirt and
grime.
Advantages: Very effective way to remove heavy
scale, paint, and grime; can reduce the amount of solvent used to clean parts;
abrasive materials may be reused.
Disadvantages: Not suited for the removal of fluid
residues; particulates in air may pose a hazard to unprotected operators;
waste generated -- a mixture of abrasive media and the material removed (paint,
soil, etc.) -- may be considered hazardous.
Modifying Existing Solvent Sinks - Significantly reduced
air emissions, worker exposure to hazardous chemicals, and solvent loss due
to evaporation can be accomplished through modifying existing solvent sink equipment.
Modifications include:
- Adding easy-to-open lids and covers
- Increasing freeboard height (height of tank above the
surface of solvent)
- Installing baskets over sink to allow parts to drip-dry
- Reducing room drafts
Advantages: Modifications can be retrofitted
onto existing sinks; simple add-ons such as a cover can reduce air emissions
significantly; reduced air emissions mean reduced solvent consumption and
hence reduced operating costs; add-on controls are relatively inexpensive;
they are easy to install and operate; using add-on controls requires no
additional labor or skills.
Disadvantages: Performance of modifications
is dependent on the design features on the solvent sink; air emissions can
be reduced but not eliminated; product loss can be reduced but not eliminated
because some residual solvent will escape from the parts to the ambient
air.
Enclosed Parts Washers - Enclosed parts washers usually combine
washing, rinsing, and drying cycles within one cabinet. Ultrasonic, high- and/or
low-pressure sprays, and immersion cleaning parts washers are available.
Advantages: Effective way to clean parts; less-hazardous
cleaning solvents, such as water and aqueous-based solutions, can be used;
reduces employee exposure to hazardous solvents; less employee time spent
washing parts; potentially cheaper cleaning materials; potentially less waste
(hazardous and non-hazardous) to dispose of.
Disadvantages: There is a risk of parts
rusting, and the resultant wastewater and sludge may be hazardous.
Alternative Solvents
Most parts cleaners use petroleum-based, low flash point solvents
(less than 140°F), such as mineral spirits. When used, these solvents may have
to be managed as hazardous waste. Fortunately, solvents with higher flash points
(greater than 140°F) and aqueous cleaning solutions (detergents) have become
available for small parts washers. As long as these alternative solvents don't
become contaminated to the extent they meet the definition of a hazardous waste,
they can be managed as a non-hazardous waste. Switching to alternative solvents
could lower your hazardous waste disposal costs.
If possible, avoid solvents:
- Containing chlorinated and halogenated compounds, such as methylene chloride
or perchloroethylene
- Containing xylene or toluene
- Having a flash point under 140°F (flammable)
There are a number of alternative cleaning solvents on the market today; two
alternatives are discussed below.
Aqueous Cleaners - Aqueous cleaners are water-based parts
cleaning agents composed of detergents, chemical additives, and/or microbes.
Uses: Acidic cleaners work well for removing
scale, rust, and oxides. Alkaline cleaners work well for removing cutting
oils and coolants, grease, and shop dirt. Neutral solutions are excellent
for removing salts, soil, and particulates.
Cost: A typical batch of solution for a 30-gallon
unit requires approximately 4 pounds of powdered cleaner and can cost between
$25 and $50. Solution life ranges from three weeks (heavy use) to 4 months
(light use).
Advantages: Most are non-hazardous; can reduce
the risk of fires; waste can be considered non-hazardous as long as it has
not been contaminated (and thus becomes hazardous).
Disadvantages: Inadequate cleaning power for some
uses; there is a risk of pitting or corrosion; rinsing with water may be required;
"fresh" solvent can more expensive than petroleum-based solvents; contaminated
waste solvent and sludges may have to be managed as hazardous waste.
Terpenes - Terpene solvents are derived from natural sources
such as pine or citrus oils. A common terpene is d-limonene, which is derived
from the oils of orange or lemon peels.
Uses: Terpenes work well in removing
heavy petroleum greases and residues.
Costs: Costs are closely tied to bath concentrations
and recyclability.
Advantages: They are non-corrosive, non-toxic,
biodegradable, and not considered an ozone depleter.
Disadvantages: Can have a very strong
odor; may be toxic to aquatic life; are highly flammable when sprayed; resultant
wastewater and sludge may be hazardous.
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Extending Solvent Life
One of the easiest, and possibly cheapest, ways to reduce
waste and prevent pollution is to extend the life of the solvents used
in an auto body shop:
- Look at your cleaning needs and avoid cleaning parts if possible.
- Because solvents are expensive, use them only for their intended
purposes. Don't waste parts cleaning solvent on floors or use
them to clean your hands.
- Minimize the amount of spilled and wasted solvent
by placing cleaning equipment near the service bays or by allowing parts
to drip-dry over pan or sink.
- Use a wire brush to pre-clean dirty parts.
- Pre-wash with old solvents for especially dirty
parts.
- Use solvent sinks with lids or enclosed
parts washers.
- Use a filtration system that filters solvent before
pumping it back into the sink for reuse (costs between $60 to $150).
- Distill or recycle used solvent on-site or off-site
(costs range from $2,000 to over $5,000).
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Regulations
for Users of
Halogenated Solvent Cleaning Machines
Federal regulations were passed that affect businesses using chlorinated
solvents. Briefly:
Who is affected:
Each individual solvent cleaning machine or parts washer that uses
any solvent containing methylene chloride, perchlorethylene,
trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride,
or chloroform, or any combination of these solvents in a
total concentration greater than 5% by weight.
The requirements
include:
**Cold Cleaning Machines
- Cover must be installed and closed when not in use
- Internal drainage facility required if solvent is volatile
- Solvent spray must be a solid fluid stream
- Specific control measures must be followed
- Specific operating requirements must be followed
**Vapor Degreasing Machines
- Lids must be used during idling and downtime
- Safety switches and thermostat must be operational
- If a carbon adsorber is used, odors should not be detectable
on the roof downwind from the stack
- Specific operation requirements must be followed (See: Federal
Regulations for Halogenated Solvent Cleaning Machines, 1997)
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Antifreeze
Antifreeze or engine coolant is typically comprised of ethylene glycol and
corrosion inhibitors. It is found in liquid-cooled engines and is designed to
transfer heat from a vehicle's engine to its radiator. Over time, antifreeze
can become contaminated with traces of fuel, metals, and grit, and can break
down to form acids that corrode the cooling system.
Because used antifreeze can be toxic to animals, birds, fish, and humans,
it should never be:
- Poured down a sanitary sewer unless it is non-hazardous and the local wastewater
treatment plant authority has approved such action.
- Poured down a septic system. The used antifreeze could contaminate or destroy
the system, endangering human health and the environment.
- Poured down a storm sewer opening or on the ground. Storm drains may drain
directly into local streams or lakes.
The main pollution prevention options for antifreeze include:
- Purchase recycled antifreeze
- Selecting less hazardous coolants
- Practicing safe handling procedures
- Extending the life of the coolant
Recycled Antifreeze
Recycled antifreeze is an option as long as it
meets ASTM Standards and will not invalidate a vehicle manufacturer's warranty.
You can purchase equipment to recycle your used antifreeze on-site, or you can
purchase recycled antifreeze from a supplier (costs about $1.50 per gallon).
Less Hazardous Coolants
Propylene glycol is another alternative to ethylene glycol
antifreeze. Propylene glycol is reported to be less toxic than ethylene glycol;
however, spent propylene glycol can become just as contaminated by the engine's
cooling system as ethylene glycol.
Safe Handling Procedures
The most effective ways to prevent used antifreeze from creating health and
environmental hazards are to:
- Stop leaks or spills from occurring.
- Fix leaky radiators immediately.
- Do not accumulate more antifreeze than you need (this
prevents it from becoming out-dated before you can use it).
- Store leftover antifreeze in its original labeled container
and make sure the lid is secure.
- Clean up spills or leaks immediately.
- Do not mix used antifreeze with other wastes. Mixing wastes
may limit your options for reusing, recycling, or disposing of the mixture.
Extending Coolant Life
Replace antifreeze only when needed. Visually
check antifreeze for particulates and test for freeze point and pH. Fresh antifreeze
or corrosion inhibitors could be added to adjust these parameters for reuse.
When usable antifreeze must be removed for repairs only, save it in
a clean, labeled container. Refill the system with this antifreeze
when repairs are done.
Recycle used antifreeze on-site or off-site (refer to the
Appendix section for lists of antifreeze recyclers and recycling equipment
suppliers).
Aerosols
Aerosol containers are common in most auto body shops. Unfortunately, they
are not very economical when you have to pay for the potentially hazardous propellant,
the packaging the product comes in (aerosol can), and disposing of the paint
left in the can.
Pollution prevention options for aerosol containers include:
- Manage waste aerosol containers properly
- Eliminate the use of aerosol containers
Managing Waste Aerosol Containers
- Try to use all the material in the can before considering it a
waste.
- Recycle empty cans if possible.
- If recycling is not an option, empty cans should be disposed of
in a licensed solid waste management facility.
- Defective cans should be returned to the supplier or manufacturer.
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Pollution
Prevention In Action
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| Helena Chrysler-Nissan in Montana phased out the use
of chlorinated solvents and aerosol sprays, and has set up a program to
recycle their used antifreeze, oil, aluminum cans, and cardboard. Last year
they saved over $10,000 by purchasing solvents in bulk form and avoided
disposing of 5,000 aerosol cans. Their recycling efforts have also enabled
them to switch to a smaller sized dumpster and reduce their monthly waste
disposal costs. |
The following series of questions can help you develop ways
of preventing pollution in automotive fluid management.
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Automotive Fluids
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YES
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NO
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| 1) Have you identified all sources of automotive fluid wastes
produced in your shop? Before you start minimizing waste in
your shop, you have to first identify your fluid waste sources. Then you
can determine which ones can be reused, recycled, or eliminated. |
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| 2) Do you use less hazardous products? Practice the
Laws of Substitution in your shop: substitute water-based or less
hazardous solvents for hazardous solvents and substitute refillable, rechargeable
dispensers for commercial aerosol spray cans. Keep in mind that
not all substitutes are less hazardous, generate less waste, or are easier
to dispose of. |
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| 3) Do you buy fluids in bulk? Buying fluids in bulk
can be cost effective and produce less packaging waste. Please note that
if you buy in bulk, keep track of the shelf-life of the product and any
storage requirements and safety issues that might be pertinent. |
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| 4) Do you use chlorinated solvents in your shop?
Some commonly used solvents and cleaners contain chlorinated or halogenated
compounds. Check a product's Material Safety Data Sheet for the words "chlor"
or "chloro" in them, like trichloroethane and methylene chloride. These
materials have been shown to be hazardous to humans and small amounts of
these materials can contaminate large quantities of groundwater. |
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| 5) Do you use halogenated solvents in your business?
Halogenated Solvents can be heavily regulated. Please research your
local rules and options for proper disposal. Consider alternative solvents
and aqueous parts washers. |
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| 6) Do you have lids on all tanks & parts washers?
Easy-to-open lids and covers help prevent the loss of product due to
evaporation and improves indoor air quality. |
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| 7) Do you use a solvent sink or enclosed parts washer?
Solvent sinks, and especially enclosed parts washers, can significantly
reduce air emissions and clean more effectively than buckets or tanks.
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| 8) Do you use parts cleaning solvent for uses other than cleaning
parts? Solvents are expensive -- treat it like gold! Use them
only for their intended purposes. Do not waste parts cleaning solvent on
floors or use them to clean your hands. |
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| 9) Do you recycle your used solvents and antifreeze?
By recycling used antifreeze and solvents you can conserve resources,
decrease the amount of fresh product that must be purchased, and reduce
the amount of waste you have to dispose of. |
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| 10) Do you use any aerosol cans in your shop? Avoid
purchasing any material sold in aerosol spray cans. Empty aerosol canisters
can be difficult and expensive to dispose of due to the sheer volume and
the danger they may pose to the hauler and the environment. Check with your
distributor for reusable self-pump dispensers and compressed air rechargeable
aerosol dispensers. They may be more expensive up front but they last longer
and save money on disposal costs. |
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Fact sheet 8 of 18
Montana State University Extension Service
Pollution Prevention Program Taylor Hall Bozeman, Montana 59717
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