Parts washers using mineral spirits and other hydrocarbon solvents are
the oldest and most common means of degreasing parts. Most mineral spirits-based
parts washers continually recirculate the solvent through a filter to extend the
time between solvent change-out. Most of the petroleum solvents used in these
washers are considered hazardous wastes due to their low flash point and
resulting ease of ignition. The variety of metal particles, dissolved
lubricants, and other debris suspended in the dirty solvent further contribute
to the hazardous nature of the solvent. The tendency of shop personnel to use
aerosol cans of brake cleaner and other chlorinated solvents over the open parts
washer also adds to the hazardous nature of used parts washer solvent.
Solvents-principally from parts washers-are typically the largest source of hazardous waste generated by vehicle repair shops. Solvent use and waste can be reduced by reducing solvent cleaning requirements (if possible); extending solvent life and recycling used solvent on-site. Recycling can be done via lease/purchase of a parts washer that filters and recycles the solvent. If 750 gallons or more per year of solvents are being disposed of as a hazardous waste, buying or leasing such a unit may make good business sense.
The need to have mineral spirits-based parts washers periodically serviced by a licensed vendor results in a substantial expense for many auto repair shops. Mineral spirits-based parts washers can use many of newer, alternative solvents that are not hazardous if used alone. Switching to one of these may very well reduce the overall expense of parts washing. Depending upon the volume of parts washing, it may be economically feasible to purchase or lease a spray cabinet-type parts washer that uses an aqueous detergent solution instead of solvents.
Aqueous (water-based) parts washers have proven to be a cost effective and environmentally friendly alternative way to clean parts for most medium- to large-sized vehicle repair facilities. Any shop using several solvent-based parts washers should investigate switching to an aqueous parts washer with a recyclable waste water system. A recyclable system minimizes or eliminates potential wastewater disposal problems. Despite their environmental benefits, certain precautions need to be taken regarding byproducts of aqueous parts washer operations. It is important to remember that the sludge that gathers at the bottom of an aqueous parts washer can be a hazardous waste due to the presence of metal particles and/or certain solvents.
DO
DO NOT
Brake and carburetor cleaners traditionally have consisted of chlorinated
hydrocarbons-such as methylene chloride-dispensed from aerosol spray cans.
Recently there has been a move toward the use of alternative solvents, primarily
in reaction to the numerous health hazards posed by chlorinated hydrocarbons and
increasing government regulation of such solvents. Chlorinated solvents are also
a problem in the auto repair shop environment due to the risk of contaminating
other waste fluids (antifreeze, motor oil, etc.) with overspray or run-off.
Careless use of chlorinated solvents can easily lead to contamination of other
fluids that would otherwise be considered non-hazardous. An aerosol can that
will not function properly but is still full may be a hazardous waste.
Hexane is a solvent. It's used mainly in vegetable oil extraction and in cleaners, degreasers, glues, and spray paints. n-Hexane is one kind of hexane. Commercial hexane usually contains 200/0 to 800/0 n-hexane, so you should treat all hexane as if it's n-hexane. Pure n-hexane is a colorless, very fast- evaporating liquid with a faint disagreeable odor.
q
Amrep Brake Parts Cleaner
q
Berryman B-12 Chemtool Carb
and Choke Cleaner
q
Berryman Chemtool
Air-Intake Cleaner
q
Berryman Non-Chlorinated
Brake Cleaner
q
Certified Labs Dylek PS
Aerosol
q
Continental Research Brake
Master
q
Drummond American Corp.
Strafe
q
Loctite Disc Brake Quiet
q
Loctite Flam Brake Clean
q
Loctite ODC-Free Cleaner
and Degreaser
q
Loctite Pro Strength
Degreaser
q
Malco Brake and Parts Wash
q
Malco Carb, Choke and
Injection Cleaner
q
Mantek DJC PS Aerosol
q
Penray Non-Chlorinated
Brake Gard
q
Seymour of Sycamore
Non-Chlorinated Brake Cleaner
q
Sherwin Williams Automotive
Cleaners
q
Sherwin Williams Brake
Parts Wash
q
Sherwin Williams
Cleaner/Degreaser
q
Sherwin Williams
Non-Chlorinated Brake Cleaner
q
Sherwin Williams Parts Wash
q
Taylor Made Non-Chlorinated
Brake Cleaner
q
Technical Chemical
Non-Chlorinated Brake Cleaner
q
Winzer Brake Cleaner,
Non-Chlorinated
q
Wurth Brake and Parts
Cleaner (liquid and aerosol)
q
Zep Aerosol Brake Parts
Cleaner
q
Zep Brake Wash (liquid)
q
Zep Parts Cleaner (aerosol)
(These are some products reported to contain hexane in a recent survey.
However, products like these can change their ingredients quite often. Be sure
to check the MSDS for whatever products you're using.)
Mineral spirits contains volatile organic compounds (VOC) that contribute
to smog formation and may be toxic when inhaled.
Dependent upon use, solvents can also contain chlorinated hydrocarbons. Although
it is effective for cleaning, mineral spirits raises significant environmental
and human health concerns.
Using solvents creates unnecessary
environmental, worker health, and fire liabilities for the shop.
Mineral spirits evaporates quickly, making worker exposure difficult to
control.
The substances and the contaminants picked up in use make spent solvents
hazardous waste
s because they are ignitable and/or
toxic.
Solvents are highly volatile and flammable you should review the MSDS
for
the product prior to its use to make sure you understand the hazards it poses.
Wear appropriate skin and eye protection.
Work in a ventilated area and/or use proper respiratory protection.
Check the MSDS to determine which respirator is suggested for a specific
solvent. Most solvents contain
volatile organic compounds; make sure that solvent containers are tightly
covered so vapors are not released.
Long-term overexposure to n-hexane can damage the nerves in the feet, legs,
hands, and arms. The damage can last a long time and may become permanent. The
symptoms include numbness, tingling, weakness (sometimes even paralysis), and
reduced ability to feel touch, pain, vibration, and temperature. Short-term
overexposure can cause headache, dizziness, loss of appetite, giddiness, and
drowsiness. Health effects have only been reported when exposure levels were
above California's workplace Permissible Exposure Limit - but people working
with n-hexane can easily be exposed to levels that high. This Health Hazard
Advisory was prompted by cases of nerve cases of nerve damage identified among
auto mechanics using spray brake cleaner that contains n-hexane.
See Appendix K for more information on n-Hexane
If you may be exposed to hexane at work, ask to see the Material Safety
Data Sheet (MSDS) for each brake and parts cleaning product in your work area.
Your employer must have an MSDS for any work- place product that contains a
hazardous substance, and must make the MSDS available to you on request. If a
product contains n-hexane, the MSDS should identify it in section 2 by the CAS
number 110-54-3.
n-Hexane enters your body when you breathe n-hexane vapors or droplets of
spray in the air. Some can enter your body when hexane touches your skin.
Your risk of health effects depends on the amount of n-hexane that enters
your body. That depends mainly on the amount (the concentration) of hexane in
the air and how long you are exposed.
Repeated overexposure to n-hexane (probably for months) can damage nerves
in the feet, legs, hands, and arms. This is called peripheral neuropathy. The
first symptom is usually numbness or tingling in the feet and legs, and then in
the hands. There may be reduced ability to sense touch, pain, vibration, and
temperature. Muscles may become weak, especially in the hands, legs, and feet.
In severe cases, there may be muscle wasting (shrinking) and, rarely, paralysis.
These effects often slowly improve if exposure is stopped, but they can last for
many months and may be permanent. The symptoms may even continue to get worse
for a few months after exposure stops.
Short-term overexposure can temporarily affect the brain, causing
headache, dizziness, loss of appetite, giddiness, and drowsiness. These effects
disappear within hours of stopping exposure.
Nerve damage has occurred among workers exposed to air concentrations of
n-hexane only a little above the workplace Permissible Exposure Limit (50
ppm-see below). If exposure is not controlled, workers can easily be exposed to
levels well above 50 ppm. Exposures high enough to cause short-term effects on
the brain are also high enough to cause peripheral neuropathy if the exposure
happens frequently.
n-Hexane is more likely to damage nerves if you use it together with
acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), or lead
acetate. Don't use hexane in combination with these chemicals.
n-Hexane breaks down in the body to form methyl n-butyl ketone (MnBK) and
2,5-hexanedione (2,5-HD). Those are the chemicals that actually damage the
nerves. Some products may contain MnBK or 2,5-HD. Do not use those products.
n-Hexane is not likely to cause health problems other than those
described above. Exposure to very high levels (20 or more times the legal
exposure limit) damaged the sperm-forming cells and the lungs of test animals.
However, these effects have never been reported in humans. Hexane does not
appear to be a special hazard to pregnancy. Hexane does not cause genetic
mutations. We do not know whether hexane can cause cancer; when it was tested in
animals, the results were unclear.
A neurologist or a doctor who specializes in occupational medicine can
test whether your nerves are damaged. The simplest way is to test nerve
conduction velocity (how fast a nerve carries a message). Nerve damage from
hexane exposure usually occurs on both the left and the right sides of the body
equally. Symptoms on just one side are likely to have some other cause, such as
diabetes, carpal tunnel syndrome, medications, or alcohol.
A urine test for the toxic breakdown product, 2,5-hex-anedione, can be
used to estimate exposure within the last week or so. The best time for such a
urine sample is at the end of the last shift of a workweek. n-Hexane and its
breakdown products are not stored in the body very long. They are eliminated
fairly quickly in the breath and urine, although the amount in your body can
increase over a workweek if you're exposed every day.
Workers who will be regularly exposed to hazardous substances should be
given a complete physical examination at the beginning of their employment. The
exam should include medical and work histories. They should also have periodic
follow-up examinations.
Your employer must protect you from being exposed to chemicals at levels
above the legal exposure limits. Call OSHA and the Cal/OSHA Consultation Service
can help you and your employer-see the "Resources" section below.
Spent mineral spirits is a hazardous waste and the shop owner is responsible for proper disposal of all hazardous wastes. Some areas of the country have already restricted use of solvents in parts cleaning operations.
Always check the product’s Material Safety Data Sheet (MSDS) to
determine safe shop practices and proper disposal method.
Parts washing produced waste solutions are subject to RCRA reporting,
waste minimization, and disposal requirements.
Parts cleaner solutions are usually contaminated with metals, oils and
dirt picked up during the cleaning process.
Most solvent-based wastes are considered hazardous because they are
flammable and/or toxic. Characterized
solvent wastes are judged toxic either because of their original chemical
composition or because they have been contaminated with heavy metals in use. Many petroleum distillates, mineral spirits, and naphtha have
flashpoints less than 140° F. These
wastes are ignition hazards.
Spent solvent waste is considered hazardous due to its ignitability,
toxicity characteristics, or because it contains listed chemicals.
No substance classified as a hazardous waste can be released into the
sanitary sewer or storm drains! A facility must determine that its discharges
are non-hazardous as described in 40 CFR 403 subsection 2.7.
Sent solvents should never be placed in a trash dumpster.
Spent parts cleaner solutions must be controlled in the shop to prevent
them from contaminating any storm water drain or sewer system.
Call your local sewer system for answers to your questions concerning
storm water runoff or discharging to the sewer.
The Cal/OSHA Standards Board sets Permissible Exposure Limits (PELs) for
the amounts of certain chemicals in workplace air. The PELs are intended to
protect the health of most people who are exposed every day over a working
lifetime.
Cal/OSHA's PEL for n-hexane is 50 parts of n-hexane per million parts of
air (50 parts per million, or 50 ppm). You may also see this stated as 180
milligrams of hexane per cubic meter of air (180 mg/m3). Legally, your exposure
may be above the PEL at times, but only if it is below the PEL at other times,
so that your average expo- sure for any 8-hour work shift is no more than 50
ppm.
If you work with n-hexane and think you might be overexposed, talk to
your supervisor or your union. If any worker might be exposed to a sub- stance
at more than the legal limit, the employer must measure the amount of the
substance in the air in the work area (Title 8, Section 5155(e)). You have the
legal right to see and copy the monitoring results (Title 8, Section 3204).
You cannot rely on your sense of smell to warn you that you are being
overexposed to n-hexane. n-Hexane has only a very faint smell, and it's not very
irritating to the eyes, nose, or throat. You can easily be overexposed without
knowing it. Measuring the amount in the air is the only reliable way to know the
exposure level.
Under California's Hazard Communication Standard (California
Administrative Code, Title 8, Section 5194), your employer must tell you if you
are working with any hazardous substances, must train you to use them safely,
and must make Material Safety Data Sheets available.
Every employer must have an effective, written Injury and Illness Prevention Program (IIPP) that identifies a person with the authority and responsibility to run the program (Title 8, Section 3203). The IIPP must include methods for identifying workplace hazards, methods for correcting hazards quickly, health- and safety training at specified times, a system for communicating clearly with all employees about health and safety matters (including safe ways for employees to tell the employer about hazards), and record-keeping to document the steps taken to comply with the IIPP.
You also have the right to see and copy your own medical records, and any
records of your exposure to toxic substances. These records are important in
deter- mining whether your health has been affected by your work. Employers who
have such records must keep them and make them available to you for at least 30
years after the end of your employment.
Keep soak tank containers closed when not in use to avoid evaporation. Solvent should never be used for the general cleaning of shop floors. When not in use, all solvent cleaning tanks must be covered and/or drain plugs closed. Solvent losses due to inappropriate usage, equipment leaks or spills, and evaporation can range from 25 to 40 percent of total solvent usage. Cans of spray cleaner should only be used when parts cannot be removed from the car and cleaned in a solvent sink.
To reduce your solvent losses use a solvent sink
with
a recirculating base tank. Place
your solvent sinks close to where cleaning will be done. Remove parts slowly after immersion to reduce drippage,
install drip trays or racks to drain cleaned parts, allowing more drainage time
over the sink after withdrawal, and turn off the solvent stream, covering or
plugging sink when not in use. Many
solvent service companies will lease you a sink (and for a small fee), pick up
dirty solvent, clean and maintain the solvent sink, and refill the sink with
clean recycled solvent. The cost
for contracting with a service provider is often less than the combined cost of
solvent purchase, sink maintenance, and waste disposal.
· Consider using less hazardous solvents or switching to a spray cabinet parts washer that does not use solvent.
·
Install a filter on your
solvent sink to greatly increase the life of the solvent.
·
Consider purchasing your
own solvent still and recycling solvent on-site
·
Sludges, filters, and
still bottoms generated from on-site solvent recovery systems are hazardous.
·
Keep spent solvent wastes
in separate, labeled, closed containers.
·
Don't mix solvents with
any other wastes, especially used oil!
Many shops have completely abandoned the use of brake cleaners and carburetor cleaners packaged in aerosol cans in favor of non-hazardous solvents dispensed from reusable spray cans. The new solvents are purchased in bulk, and used to refill the reusable spray can. The can is then pressurized with compressed air from the shop system, via a fitting on the top of the can. Not only are the new solvents more environmentally friendly, they are in many cases more effective cleaners than the solvents they replace. In addition, the compressed air-driven spray cans deliver a more concentrated stream of cleaner to the part in comparison to aerosol spray cans.
Make sure that there is good ventilation. "Local exhaust
ventilation" is most effective; it captures contaminated air at the source,
before the hexane can spread into your breathing zone. Next best is general
ventilation, which uses a fan-powered system to bring fresh air into the work
area. Open doors and windows usually provide very little ventilation. An indoor
fan that just blows contaminated air around without removing it from your work
area is not effective.
Hexane has very poor "warning properties" (that is, it has
little odor and isn't very irritating). Only supplied-air respirators are
approved for protection against hexane. Filter respirators are not approved,
because when the cartridge "wears out," there is no warning to alert
you that the respirator no longer provides protection.
It may be hard to avoid getting parts cleaning products on your hands. If
you can use a water-based cleaner and make sure that it's pH neutral (to prevent
irritation and burns), you probably won't need protective gloves. If you must
use hexane products and it is likely that you'll have a lot of skin contact,
wear protective gloves and replace them often. Viton and polyvinyl alcohol are
recommended, and Silvershield and chlorinated polyethylene are also good. Other
glove materials, such as latex rubber, provide very poor protection against
hexane. California law requires an employer to supply gloves or any other
necessary safety equipment at no cost to the employee.
The surest way to protect yourself is to switch to products that don't
contain hexane. Avoid using products for which you do not have an MSDS.
Especially avoid using products that combine hexane with acetone, MEK,
MIBK, or lead acetate.
Switch to water-based (aqueous) cleaners for cleaning of brakes and other
vehicle parts. Some aqueous cleaners work as well as solvent cleaners, and they
don't pollute the air in the workplace or the environment. Unlike solvent
cleaners, aqueous cleaners are usually non-flammable. An aqueous cleaning system
will probably even save the shop money, because an automated aqueous spray
cabinet for cleaning parts can greatly reduce labor time. Aqueous cleaner also
lasts longer, so you won't need to buy as much of it. Environmental compliance
may also be easier, and you can reduce your hazardous waste disposal costs.
Experience shows that switching to an aqueous cleaning system can pay for itself
within as little as three months to a year. Many vendors will offer their
aqueous systems free of charge for a testing period of a week to a month to help
you select the best system for your shop. If you can't switch to hexane- free
products, take other steps to limit your exposure.
If you must use hexane products, use as little as possible. Keep
containers closed between uses. Hexane can evaporate quickly from a
hexane-soaked rag, so make sure that used rags are kept in a well- ventilated
area.
DO
DO NOT
Because of the special requirements for cleaning automotive brakes, this
subject requires additional coverage. Asbestos
and other particles can cause worker safety issues as well as environmental
impact. Aerosol spray cans have
become the standard and with them some very serious problems.
These will be covered in more detail in a following section.
To avoid some of these problems, the best alternatives are aqueous brake
washers. Aqueous brake washers perform as effectively as
traditional solvent washers, they are better for the environment, and they
reduce hazardous waste management costs and liability.
Washing brakes before inspection and repair helps create a
clean work area. It also removes dust and debris that prevent the brakes from
functioning properly and cause squeaking and grinding. Brake washing can be performed using
three devices:
The best environmental practice is to use aqueous brake washing units. Aqueous brake washing units use water-based cleaning solutions. These solutions are nonflammable and generally less toxic than petroleum-based solvents. Furthermore, aqueous cleaners contain little or no volatile organic compounds (VOCs) that can harm the environment and shop employees. Aqueous brake washing units are widely available and perform as well as solvent-based equipment; however, aqueous brake washers have the following advantages:
·
Little or no solvent vapors or aerosol mists that can be harmful to your
workers’ health.
·
Nonflammable
·
Do not contribute to smog formation, climate change, or ozone depletion.
·
No empty aerosol cans discarded as bulky, non-biodegradable trash.
·
Reduces overall environmental and safety liabilities for the shop.
·
Can save you hundreds of dollars per year after payback period
Most aqueous brake washing units function much like sink-top parts
cleaners. Aqueous brake washers
feature a portable basin that can be adjusted to fit under the wheel assembly.
Most technicians prefer units with adjustable sink height. Compressed air
pumps the aqueous solution through a hose and a flow-though brush.
A filter is often used to collect debris and keep the solution clean.
Aqueous units range in cost from $500 to $1,200 to purchase, or $45 to
$85 per month to lease (lease cost includes waste management).
Spent soak tank solutions should be recycled or properly disposed of at a
permitted hazardous waste disposal facility.
Many shops have cut down on the amount and toxicity of solvents they are
using by turning to less-toxic alternatives.
There are a number of companies who provide on-site recycling equipment
designed for the filtration or distillation of parts washing solutions.
You should also consider changing to water-based and/or biodegradable
cleaners as substitutes for petroleum based solvents.
Check with your local trade association or your local or state regulatory
agencies for information and phone numbers.
More efficient parts washing procedures can help eliminate waste.
Monitor the effectiveness of the parts washing solvent and do not
change-out the solvent until it no longer will clean parts to the level
expected. Extend the life of your
cleaning solution by using "dirty" solvent for pre-cleaning of dirty
parts, before they are put into the main parts washer.
Minimize the number of parts washing stations in your shop.
Make sure your part washers are turned off and if they have lids, keep
the lids closed when not in use.
Water-based parts cleaning solutions can also be dangerous because of their caustic properties. Carburetor cleaners are corrosive liquids that contain chlorinated compounds. Carburetor cleaner should be segregated from other wastes. Waste carburetor cleaner should be accumulated separately for proper waste management in a suitable container or system. Consider eliminating chlorinated carburetor cleaner and switching to a less hazardous, non-chlorinated cleaner.
Hazardous solvents should always be used only when no other cleaner is
suitable for the job. The major
ways to avoid or reduce the generation of solvent waste include eliminating the
need to use solvent; finding adequate substitutes for solvents; minimizing
losses associated with solvent use; and to segregate, recycle, recover, and
reuse waste solvents.
Terpene based cleaners are increasingly being used in place of Stoddard
solvent. The terpene cleaners are
available commercially as water solutions with surfactants, emulsifiers, rust
inhibitors, and other additives. Terpenes
have tested favorably as substitutes for halogenated solvents for removal of
heavy greases and oily deposits.
Pre-cleaning parts with a wire brush, followed by steam cleaning, high-pressure wash,
or hot bath that recycles an aqueous solution are efficient approaches for
minimizing or eliminating the use of hazardous solvents.
Use halogenated solvents judiciously! Solvent should never be used for
the general cleaning of shop floors, and should only be used in a
well-maintained self-contained cleaning system. When not in use, all solvent cleaning tanks must be covered
and/or drain plugs closed. Solvent
can be wasted through equipment leaks, spills, poor application techniques and
evaporation.
The cost for collection and/or the disposal of part cleaning solutions
can be determined by making contact with service providers who reclaim,
recondition and recycle solvents.
Because parts cleaning solutions are considered a hazardous material you
may be subject to county Waste Generator fee and may need to update your
Business Emergency Response Plan and Hazardous Communications Plan.
The recycling and disposal of part cleaning solutions require record
keeping and reporting. Generators
that ship spent solvents for off-site treatment and disposal are required to
fill out a hazardous waste manifest. If
you have questions, check with your local governing agency.
Minimize the costs and liabilities by switching to aqueous cleaners.
Aqueous cleaners are water-based solutions that, unlike petroleum-based
solvents, are typically nonflammable and contain little or no VOCs.
Instead of dissolving grease and solids, aqueous cleaners rely on heat,
agitation, and soap action to break dirt into smaller particles.
Although they clean differently, aqueous cleaners perform as well as
solvents. For this fact sheet,
aqueous cleaners are defined as water-based cleaners that contain less than 5%
(50 grams per liter) of VOCs. Hundreds
of aqueous cleaner formulations are commercially available.
The California South Coast Air Quality Management District maintains a
list of aqueous solutions that are certified to contain less than 5% of VOCs;
this list is available on the Internet at www.aqmd.gov/tao/cas/prolist.html.
The cleaning equipment used is critical to successful aqueous cleaning
because it applies two important mechanisms to the cleaning process: mechanical
force and heat. Two types of
aqueous cleaning units that are applicable to most auto repair shops- sink-top
and spray cabinets. Most shops will
likely meet all their cleaning needs by implementing both types of units.
Specialty shops that clean many transmissions and carburetors may also
want to investigate using ultrasonic and immersion type units.
The wastes generated from aqueous cleaning should be managed as described
in the following section.
Aqueous cleaning solutions may qualify as hazardous waste after extended
use because concentrations of metals such as cadmium, copper, lead, and zinc may
exceed state or federal limits. Therefore,
auto repair shops should always use a licensed waste disposal company to manage
waste solution. Many waste disposal
companies will analyze the waste solution for you to determine whether it is
hazardous. The cost of disposal
will vary according to the characteristics of the waste and the volume
generated, but will generally be $2 to $4 for a gallon if it is a hazardous
waste and $1 to $2 for non-hazardous waste.
Unless you obtain permission from your local sewage treatment agency, do
not dump waste solution in the sewer or septic system.
When purchased, aqueous brake washing solutions contain proprietary
compounds that are either non-hazardous or considerably less hazardous than
solvents. With proper filtration
and regular addition of fresh solution to make up for evaporative losses, many
shops can go for years without requiring solution disposal.
Over time however, contaminants build up creating sludge and making the
solution less effective. Waste
solution, sludge and filters may contain metals washed off the brake assembly,
or solvents that mistakenly dripped into the sink and contaminated the solution. Waste solution, sludge and filters should be shipped off-site
as either hazardous or non-hazardous wastes.
Get data, or test the waste stream at least once to make this
determination, and dispose of the waste solution and filters accordingly.
Some unit vendors will dispose of the spent solution for you and include
the cost of this service in the unit’s rental price.
An informal survey of San Francisco Bay area
shops revealed that aqueous solution is changed about once every 3 years, on
average.
Used filters may be recycled along with spent engine oil filters with the
permission of the recycler. Contact
your oil recycler to determine if they will take your filters.
Some recyclers will only accept used filters if they are encased in metal
shells like engine oil filters, and some states prohibit recycling aqueous
filters with engine oil filters. If
they are not recycled with engine oil filters, used filters should be managed as
hazardous waste and disposed of by a licensed waste disposal company.
Contact your state environmental agency to learn if any special rules
apply to used filters.
Oil skimmed from an aqueous cleaning solution can be managed as used oil
and recycled. Most recyclers will
accept skimmed oil with used motor oil as long as it is not contaminated with
solvent.
Little or no sludge will accumulate in aqueous cleaning units with
filtration, but units without filtration may accumulate sludge at the bottom.
This sludge may be disposed of along with waste solution.
Most waste disposal companies will accept a certain percentage of solids
in the waste solution. If the
sludge is separated from the solution, the sludge may not be disposed of as
solid waste unless tested to determine if it is non-hazardous.
If you use aerosol brake cleaners to spot clean or dry brakes after
aqueous brake washing, be aware that many aerosol products contain F-listed
chemicals. An F-listed chemical is
a chemical that makes each waste it contaminates a hazardous waste, no matter
what its concentration in the waste is. Even
one drop of an F-listed aerosol solvent that drips into your brake washing
solution is enough to make it a regulated hazardous waste!
If you must use aerosol products to spot clean, always move the aqueous
brake-washing unit away from the brake area first.
To save time and avoid potential regulatory problems altogether, use
compressed air to dry brakes rather than aerosol brake cleaner.