Pollution Prevention for Auto Maintenance and Repair …infohouse.p2ric.org/ref/50/49049.pdf ·...

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Pollution Prevention for Auto Maintenance and Repair Shops Kansas State University Pollution Prevention Institute

Transcript of Pollution Prevention for Auto Maintenance and Repair …infohouse.p2ric.org/ref/50/49049.pdf ·...

Pollution Prevention

for Auto Maintenance andRepair Shops

Kansas State University Pollution Prevention Institute

Automotive repairs and maintenance work can generate prob-lem wastes and regulatory headaches for shop owners.Mechanical repairs usually require cleaning and dismantling ofthe engine and other heavily soiled components. Maintenancework performed by repair shops consists of fluid changes,repair and rework of fixable components, and replacement ofnonfunctional nonrepairable parts. These processes leave shopowners with fluids such as used antifreeze, engine oil, trans-mission fluids, and cleaning solvents to dispose of, as well asnonrepairable vehicle parts.

This fact sheet provides regulatory guidance and recommendedpollution prevention (P2) opportunities to help shop ownershandle their wastes in cost-effective and environmentally soundways.

Dealerships and aftermarket repair shops must realize it is theirresponsibility to make hazardous waste determinations on allwaste streams from their operations. Shops can use a MSDS,process knowledge, or lab testing (by KDHE-certified labs) tomake a hazardous waste determination on these wastes. It is agood practice to document those determinations and keep thepaperwork in a folder dedicated to environmental compliance.Repair operations often involve the Resource Conservation andRecovery Act (RCRA) hazardous and solid waste regulations,Clean Water Act (CWA) water discharges and oil pollution regu-lations, and possibly the Clean Air Act (CAA) air regulations forpainting or other regulated solvent emissions.

It is a business’s responsibility to be in compliance with allenvironmental regulations that apply to it. Sometimes this canbe a daunting task. The Kansas Small Business EnvironmentalAssistance Program at K-State provides free, confidential assis-tance to Kansas businesses to help them understand their regu-latory obligations and to reduce their regulatory responsibilitiesthrough pollution prevention practices and technologies.

P2 reduces the amounts of pollution generated, reducing haz-ards to workers, the public, and the environment. P2 mayinvolve the following approaches:

n substitution of a less hazardous material to do the jobn improvements in work practices and housekeeping meth-

ods that will reduce spills and wastes and conserve naturalresources

n utilization of a new technology or equipment that elimi-nates use of a hazardous material or an unnecessaryprocess

Adopting P2 in auto repair and maintenance shops can reduceraw material purchases, waste-related costs, paperwork, andmany of the liabilities associated with hazardous materials’ useand disposal. Management commitment and employee partici-pation are essential to the success of a pollution preventionprogram.

Major waste streams from auto repair that provide P2 opportu-nities include the following:

n vehicle fluids such as motor oil, antifreeze engine coolant,transmission fluid, battery fluid, and brake fluid

n refrigerants n non-repairable partsn parts-washers solventsn shop cleanup materials from spills and leaks

Proper management of these waste streams should include goodhousekeeping practices to minimize raw material’s use andspillage, waste segregation, recycling of materials where possi-ble, and employee and consumer education to reduce unneces-sary fluid changes and excessive equipment wear. Pollutionprevention methods that reduce waste at the source of genera-tion are mandated by the Pollution Prevention Act of 1990 asthe preferred method of waste control. By choosing methods ofoperation that don’t create or use a hazardous material, autorepair shop owners will play a significant role in improving thehealth and environment of the communities they live in.

What is pollution prevention (P2)? P2 is a more efficientuse of materials and resources that eliminates pollution atthe source of generation, in order to reduce wastes, airemissions, and contaminants going into the environment.Shop owners may refer to these techniques simply as“good business practices” or “standard operating proce-dures.” P2 is preferred over traditional end-of-pipe controlsthat deal with pollution after it’s been generated, usually atan extra cost to the business.

Auto Maintenance and Repair Shops

Reducing Waste and Achieving Compliancein the Auto Repair IndustryHeavy metals from welds, radiators, and other engine com-ponents can become entrained in fluids associated with vehi-cle operation. If these metals are present above certain con-centrations known as “threshold limit levels,” the fluid isconsidered hazardous. The toxicity characteristic leachingprocedure, TCLP, is a testing procedure used to evaluate awaste stream’s toxicity. An entire TCLP test is not necessary(and is very expensive); operators may use “process knowl-edge” to determine which contaminants to test for on thesample they send to the lab. A “totals test” can also be sub-stituted for a TCLP test for regulated metals testing and it’slower in cost than a TCLP. Lead, chromium, and cadmiumare the metals most often associated with contamination ofcleaning solutions and waste antifreeze in the auto repairindustry. For more information on testing options, see ourfact sheet “Regulated Metals: The Rule of 20” athttp://www.sbeap.org/ppi/publications/ruleof20.pdf. For more assistance with questions on what tests should berun on a sample, call an SBEAP specialist at 800-578-8898.

Used Oil

Hazards and Proper Handling: Used oil must be disposed inan environmentally sound manner—never in the environment.It is easily recycled, and improperly disposed oil can destroyplants and animal habitat as well as harm aquatic life. Used oiland other auto fluids should never be used for weed control ormixed with a material that would be a hazardous waste, such asa low-flash solvent or gasoline, as it would make the entiremixture a hazardous waste. New oil containers should bedrained thoroughly before disposal. Bulk waste containersshould be marked “used oil,” and as a best management prac-tice, be kept closed at all times and kept covered with sec-ondary containment to prevent possible storm water contami-nation if stored outside. Large quantities of oil products (cumu-lative amounts more than 1320 gallons stored in containersgreater than 55 gallons) and wastes may require secondary con-tainment and other special handling under the Oil Pollution Act(see the SPCC reference below).

P2 Opportunities: Used oil can be burned on site in a spaceheater, recycled, or used for fuel blending. (When sent off sitefor recycle or fuel blending, the oil should be shipped under atolling agreement with a KDHE-registered used-oil trans-porter.) Used-oil burner capacity must be no more than 0.5 mil-lion BTU per hour and must be exhausted to the outside of thebuilding. As of late 1998, used-oil burners can now take usedoil from other businesses if the used oil is determined throughproper testing to be “on-spec.” This testing is required to pro-tect burners of used oil from receiving an oil/solvent mixturethat could blow up the heater or release toxic air pollutants.The generator of the oil or the person receiving the oil musthave it tested to verify the following:

n a minimum flash point of 100º Fn total halogen content of less than 1000 ppm (parts per mil-

lion)n arsenic content less than 5 ppmn cadmium content less than 2 ppmn chromium content less than 10 ppmn lead content less than 100 ppm

The recipient, or burner, of the used oil should have copies ofthe tests on site for a minimum of three years for each batch ofoil received for burning in the heater.

n Bulk oil is cheaper than quart containers and can signifi-cantly reduce the amount of solid waste leaving your shop.Bulk oil is dispensed more efficiently, reducing spills andcleanup wastes associated with individual bottle use.Limited recycling options exist for one-quart used-oil con-tainers.

n Offer customers high-performance longer-lasting oils:some of these products last up to four times as long as reg-ular oil and have been proven to protect engines better.

n Fleet operations should explore “predictive oil mainte-nance,” which dictates oil changes based on quality para-meters instead of a time schedule, to reduce oil purchasesand used-oil generation.

n Use “pop-up” level indicators or gauge glasses on bulk-oilstorage containers to prevent spills from overfilling.

Disposal and Regulatory Responsibilities: Used oil is easilyrecycled or reused, but while in storage it should be stored inleak-proof containers and shipped to reclaiming/recyclingfacilities; never send used oils or other liquids to a landfill.Used vehicle fluids cannot be poured on the ground, in water-ways, or used as a dust control agent for roads or parking lots.Containers and fill pipes must be marked with the words “usedoil” not “waste oil.” Used oil and bulk oil stored in 55-galloncontainers or larger must be counted toward total on-site stor-age threshold capacity for spill, prevention, control, and coun-termeasure plans (SPCC). If your shop has the storage capacityto store more than 1320 gallons of oil or oil-related materialsabove ground, or if you have more than 42,000 gallons ofunderground storage, your shop must have an SPCC plan. Fora copy of the final SPCC regulation go tohttp://www.epa.gov/oilspill/pdfs/40cfr112.pdf . A sample SPCCplan incorporating changes from the final rule can be found athttp://enviro.nfesc.navy.mil/ps/spillprev/ . For KDHE’s technical guidance documents on used-oil man-agement, go tohttp://www.kdhe.state.ks.us/waste/bwm_tech_guide.html .

Oil Filters

Hazards and Proper Handling: Used-oil filters should behot-drained and crushed where possible for complete removalof oil and volume reduction before disposal.

P2 Opportunities: Oil filters do have recycle value and shouldbe recycled whenever possible.

Disposal and Regulatory Responsibilities: Oil filters can usu-ally be disposed in landfills after they are thoroughly drainedand do not contain any free liquid. However, some landfillsmay prohibit oil filter disposal; check with your receiving land-fill to be sure. Oil filters can retain as much as one cup of oilafter draining; crushing oil filters will effectively remove allliquid present and reduce the volume going to the landfill.Some household hazardous waste (HHW) facilities will takeoil filters for recycle; check with your local HHW before dis-posal.

Transmission Fluid

Hazards and Proper Handling: These fluids consist of blend-ed oils. Use drip-proof catch pans to catch fluids and store inbulk containers equipped with secondary containment and levelindicators. Used-oil haulers usually allow this fluid to be mixedwith used oil.

P2 Opportunities: Transmission fluids and other hydraulicfluids should be captured for re-refining or fuel-blending pro-grams. Many fuel-blending facilities will allow these fluids tobe mixed with used oil. Always ask your waste hauler if he orshe can accept these fluids before mixing.

Disposal and Regulatory Responsibilities: Never dispose ofin the environment or in landfills.

not recycled, a hazardous waste determination must be madeby testing to determine regulated metals content; if hazardous,it must be labeled “hazardous waste.” In some cities, the publicowned treatment works (POTW or wastwater treatment plant)may allow this material to go to the sanitary sewer; however,more and more POTWs are discouraging this practice. Callyour local wastewater treatment operator for information onaccepted practices in your locality; if discharge of antifreeze isallowed, obtain a letter from them as documentation for yourenvironmental records. Never pour antifreeze on the ground orin waterways.

Nonrepairable Automotive Parts

Failure of nonrepairable parts generates a large waste streamthat is costly as a solid waste. Shops that store enough body orvehicle components to equal 10 vehicles may be considered asalvage yard operation with additional regulatory requirements.

Hazards and Proper Handling: Discarded parts should bekept undercover if possible when stored outdoors. These partsmay be coated with oil or grease, or as in the case of radiators,may contain lead residues that create harmful storm waterrunoff endangering fish, wildlife, and public drinking watersupplies.

P2 Opportunities: When parts do fail due to routine wear,accidental damages, or neglect, they should be recycled to partsre-manufacturers or metal recyclers if feasible. Parts such asasbestos-containing brake shoes and pads may need to be han-dled as a “special waste.”

Disposal and Regulatory Responsibilities: Many parts can belandfilled if all free liquids are removed from them; however,recycling is preferred to save landfill space. Asbestos brakepads and dusts from brake cleaning and turning are considereda “special waste” in Kansas and require a special waste autho-rization from KDHE for landfill disposal. For questions on spe-cial waste disposal, call solid waste specialist, RichardBronaugh, KDHE, at 785-296-1120; or for a special waste dis-posal application go tohttp://www.kdhe.state.ks.us/waste/download/spec_wd_req_FORM.pdf.

Refrigerants

Refrigerants in older motor vehicle air conditioners (MVAC)may be chlorofluorocarbon-12, better known as CFC-12, R-12,or Freon, which is associated with the breakdown of the ozonelayer around the earth. The ozone layer is an important layer ofthe earth’s atmosphere that blocks carcinogenic radiation fromthe earth’s surface. All ozone-depleting materials from automo-bile air-conditioning systems must be captured and reusedwithout being released to the atmosphere. Most air conditionersin vehicles made after 1994 use hydrofluorocarbon-134a, alsoknown as HFC-134a or R-134a.

Brake Fluid

Hazards and Proper Handling: Brake fluids can usually beadded to used oil for recycle. However, brake fluids can alsobecome contaminated with regulated solvents used to cleanbrake lines and pads. Nonhazardous brake fluids should behandled as an oil with tightly fitting, leak-proof seals and pro-tected from spills or leaks to the environment.

P2 Opportunities: Used brake fluids may be recyclable withused oil if not considered a hazardous waste.

Disposal and Regulatory Responsibilities: A waste determi-nation should be made on brake fluid to determine if hazardousingredients, such as a chlorinated cleaner or other regulatedcontaminants, are present. KDHE will allow up to 1000 ppm ofa halogenated material as a contaminant in used oil before it isclassified as a hazardous waste. So brake fluids contaminatedwith chlorinated cleaning solvents below this level may berecycled with used oil. Brake fluid should never be poureddown drains, into sewers, or on the ground.

Engine Coolant

Hazards and Proper Handling: Antifreeze mixtures forengine coolant usually contain ethylene glycol, a poisonouscompound that should be handled carefully to avoid possibleingestion by animals or humans. Engine coolant can also becontaminated with lead, chromium, or cadmium regulated met-als that may make it a hazardous waste; it should never bepoured on the ground, in storm sewers, or in waterways.

P2 Opportunities: Engine coolants can be economically recy-cled on site or off site and reused in vehicles. This reduces theamount of waste leaving your shop and can drastically reduceraw material purchases to increase your bottom line profits.Recycling efforts such as this enhance your public image as anenvironmentally conscious shop owner. Filters from coolantrecycling machines should be dry and tested for heavy metalcontamination before disposal. Testing for heavy metal conta-mination may be done as a composite sample (piece of each fil-ter) collected over a period of time. This approach offers themost economical way to be sure your filters are safe for landfilldisposal. If your filters contain heavy metals above thresholdlimits, the filters must be disposed of as a hazardous waste. ATCLP or total metals test is acceptable.

Antifreeze recyclers start at $2,000 and can be purchased as anon-car filtration unit or as a batch unit that filters or distillspure antifreeze. Some shops may choose to have a recyclingservice come to their facility; prices vary but may be as high as$1.75 per gallon of antifreeze.

Disposal and Regulatory Responsibilities: Antifreeze that isrecycled on site or off site does not have to be tested or countedtowards monthly hazardous waste generation rates in Kansasand should be labeled “antifreeze for recycle.” If antifreeze is

ators (they generate more than 55 pounds of hazardous wasteper calendar month).

P2 Opportunities: Minimize the amount of aerosol productsused at your facility. Many shops have switched to refillablepressurized containers. This technology allows all the productto be used, whereas aerosol can dispensers may leave as muchas 15–25% of the product in the can. Refillable containers alsopromote the purchase of product in bulk, offering savings inmaterials purchases, wasted product, and waste cans.

Disposal and Regulatory Responsibilities: Like all materialsthat become waste, each shop is responsible for determining ifthe material is a hazardous waste at the time when the materialwill be disposed. Empty nonhazardous aerosol cans may berecycled as scrap metal, disposed of in the trash, or disposed asa hazardous waste. Empty cans that previously contained haz-ardous products or propellants are conditionally exempt fromhazardous waste regulations, if they are recycled as a scrapmetal or meet the definition of RCRA empty. Intact, discardedaerosol cans are hazardous waste if the cans still contain aproduct or propellant that is considered hazardous. For detailedguidance on disposal of aerosol cans, see KDHE’s technicalguidance document HW02-02, “Recycling and Disposal ofAerosol Cans,” athttp://www.kdhe.state.ks.us/waste/guidance/hw02-02.pdf.

Parts Washing

Most vehicle repair shops use some type of parts washer toclean parts removed from the car prior to repair work. Parts-washing processes and waste paint thinner or gun-cleaning sol-vents are generally the most problematic waste streams and areresponsible for most of the hazardous waste generated at repairshops. Soils from parts washing include dirt and sludge, oilresidues, and regulated metals. The regulated metal concentra-tions can build up in parts washers to make them a hazardouswaste. Even parts-cleaning solutions that are nonhazardousbefore use, such as aqueous, detergent-based cleaners and high-flash-point solvents (f.p. > 141º F) contaminated with thesesoils, can become a hazardous waste due to metals buildup.Paint-gun cleaners and low-flash solvents used for parts wash-ing are usually hazardous due to their low flash points andbecause of ingredients regulated as “listed” wastes such astoluene, xylene, and acetone for example. Although there areseveral workable P2 options for these two wastes, shop ownersmust remember that many times it’s the soils cleaned off theparts, not the cleaner itself, that can make the cleaner a haz-ardous waste.

Approaches to reducing pollution from the parts-cleaning processes include the following:

n Use a less hazardous cleaning system.n Use a less hazardous solvent.n Recycle used solvent cleaners.n Maximize solvent or cleaner life.

Hazards and Proper Handling: All shops must have Section609 certified operators and recycle equipment that can recoverthe refrigerant and reprocess it through an oil separator, filter,and dryer for reuse. Intentional venting of ozone-depletingrefrigerants to the atmosphere is prohibited by law, with finesup to $27,500 per day.

P2 Opportunities: Reuse refrigerants in other vehicles or shipoff site for recycling.

Disposal and Regulatory Responsibilities: Refrigerants arevery stable compounds with no economically feasible way todestroy them; all refrigerants should be captured for reuse /recycle / resale. Your operators must be certified technicians ifyou intend to reuse recycled refrigerant from MVACs, or if youpurchase refrigerant recovered from MVACs and will recycle itbefore recharging into an MVAC. Certified technicians mustuse EPA-approved recovery/recycling or recovery equipmentwhen working on an air-conditioning unit. For detailed infor-mation on specific record keeping and reporting requirements,check out the fact sheet “Refrigerants: Common Problem forSalvage Yards,” athttp://www.sbeap.org/ppi/publications/refrigerants.pdf.

Batteries

Hazards and Proper Handling: Used lead-acid batteries arenot considered hazardous waste as long as they are intact andrecycled. Split or broken batteries must be handled as a haz-ardous waste, due to sulfuric acid and lead contents. Materialsused to clean up spills and leaks become hazardous waste andrequire disposal as such.

P2 Opportunities: It is important to store used batteries in aplace protected from the weather where they won’t freeze.Recycle batteries; use thick cardboard to separate layers if bat-teries must be stacked to prevent breakage and don’t store morethan four high; handle properly to avoid unnecessary wastegeneration. Secondary containment should be used to preventhazardous material leaks, and baking soda should be kept onhand to neutralize spilled battery acid. Spill cleanup from bro-ken batteries may be a hazardous waste and should be collectedand tested for lead and corrosivity.

Disposal and Regulatory Responsibilities: If not recycled,lead-acid batteries must be disposed of as hazardous waste.

Aerosol Can Products

Hazards and Proper Handling: Almost all businesses andindustries use chemical products purchased in aerosol cans.These products may range from a nonhazardous window clean-er to a highly toxic pesticide or solvent. Generally, most emptyaerosol cans may be recycled as scrap metal or disposed in thetrash. However, problems arise when defective, unused, orunwanted cans of product or expired product need to be dis-carded by businesses that are regulated hazardous waste gener-

Disposal and Regulatory Responsibilities: A hazardous wastedetermination must be made on solutions before they are dis-posed. If regulated metals are below hazardous waste levels,the aqueous solutions may be allowed to go to the sanitarysewers, if acceptable to the local wastewater treatment plant orPOTW. Hot tanks are usually a hazardous waste due to pH andheavy metal contamination. Oils should be removed by a skim-mer or other method before disposal. Hot soap washer fluid canNOT be discharged to septic systems or storm sewers becauseit may cause environmental damage to groundwater suppliesand storm water discharge areas, respectively. If connection toa city sewer is not possible, the water may need to be collectedin a tank and hauled to the local wastewater treatment facility,or an evaporator system may be installed to eliminate thewastewater stream, as long as the wastewater is not considereda hazardous waste. Sludge from these washers should be testedfor hazardous constituents before disposal. Units equipped withevaporator units can only be used to evaporate the solution if itis not a hazardous waste or if the evaporator system is totallyenclosed with a condenser to recapture the steam from theprocess. KDHE prefers to pre-approve evaporation units priorto purchase and use.

Cost: Small hot soap washers start at $2,500; medium-sizedunits that will accommodate transmissions and engine blocksstart at $5,500. They are available with recirculating systemsfor maximum water and detergent use, or with evaporator sys-tems to eliminate wastewater from the machine, leaving only asludge residual. Models with evaporators are usually moreexpensive and are usually not a totally enclosed system with acondenser.

Aqueous Cleaning with Conventional PartsWashers

Hazards and Proper Handling: Aqueous systems used withconventional parts washers are fairly inexpensive, economical,free-standing washers that can use common household deter-gents to effectively remove oily soils. Aqueous cleaning solu-tions may be used in conventional “sink-on-a-drum” partswashers with common household detergents, alkaline cleaners,or microbial cleaners, and may require the addition of a rustinhibitor for corrosion control, if needed.

P2 Opportunities: Units are available as heated systems toincrease cleaning efficiency and can be equipped with a filter-ing mechanism to prolong the life of the solution, making themvery economical to use. Conventional parts washers with aque-ous cleaners pose fewer health risks to employees, eliminatefire hazards, and may be associated with lower operationalcosts if cleaning solutions are changed before becoming a haz-ardous waste.

Disposal and Regulatory Responsibilities: A hazardous wastedetermination must be made on solutions before they are dis-posed.If regulated metals are below hazardous waste levels, theaqueous solutions may be allowed to go to the sanitary sewers

The remainder of this fact sheet covers the previously cited P2opportunities for parts washing in detail and provides regulato-ry information to help shop owners determine the regulatoryresponsibility associated with each option.

Many water-based cleaning formulations are available for partscleaning. These cleaners generally contain surfactants orbuilders with additives like rust inhibitors if needed. Some ofthe cleaners may contain a solvent additive such as a terpene,glycol ether, or alcohol. Water-based cleaners do not requiresolvent additives to be effective. In some of the cleaning sys-tems, workers' hands must contact the cleaner; cleaners used inthese units must be neutral or only slightly alkaline to avoidskin irritation.

Another important aspect of aqueous cleaners is how the clean-er works: does it emulsify the oil and grease or reject it? Withcertain types of enzyme systems, emulsifying cleaners areappropriate. In nonenzyme systems, however, cleaners thatreject oil are more practical. The oil and grease will separateout and float on the surface of the bath where they can beremoved with a skimmer. The cleaning formulation will have amuch longer bath life and be less costly to operate if it isdesigned to reject oil and grease.

Hot Tanks and Hot Soap Cabinet Washers

Hazards and Proper Handling: Hot tanks and hot soapwashers are heated systems that contain a hot aqueous deter-gent or caustic solution to clean the parts. The part is sub-mersed into a tank with air or mechanical agitation, or is jet-sprayed with a high-pressure stream within an enclosed “wash-er” to remove the soils. Hot soak tanks with strong causticsshould be kept covered when not in use, and personal protec-tive equipment must be supplied to employees to prevent con-tact with the chemical. Both of these cleaning systems can usu-ally be used for long periods of time.

P2 Opportunities: These machines reduce employee expo-sures to hazardous solvents, require less “hands-on” labor,decrease fire hazard from flammable solvents, and may beassociated with less hazardous waste for disposal. Aqueouscleaners pose fewer health risks to employees, eliminate firehazards, and may be associated with lower operational costs ifcleaning solutions are changed before becoming a hazardouswaste. However, permission from your publicly owned treat-ment works (POTW) is required for discharge of any waste-waters, even if they are not a RCRA hazardous waste. Keep inmind that your POTW or wastewater treatment plant’s dis-charge limits are different from hazardous waste constituents,so you must work closely with the POTW that you discharge toin order to establish discharge limits for waste aqueous clean-ing solutions.

Less Hazardous Cleaning Systems

with written permission from the wastewater treatment plantoperator. Oils that accumulate should be skimmed off the solu-tion daily and combined with the used-oil stream for recycle.Shop operators must obtain approval from their local waste-water treatment plant operator before discharging aqueouswash waters, and should never discharge these fluids to septicsystems, storm sewers, or on the ground. A hazardous wastedetermination should be made on sludge to determine disposalrequirements.

Cost: Two options exist: the sink-on-a-drum and an immersionunit. The first consists of a sink mounted on a drum that has afluid capacity ranging from about 15 to 40 gallons. It contains aheater, pump, faucet, and brush applicator. Cost of these unitsranges from about $400 to $1,700, depending on constructionmaterials and features. They can contain filters and/or oil skim-mers which extend the bath life of the water-based cleaner. Thedifference between the immersion unit and a sink-on-a-drum isthat the immersion system has a false sink that can be removedand a reservoir accessible for cleaning or soaking. This unitalso contains a heater and a pump and has a liquid capacity of30 to 60 gallons. Again, it can be constructed of metal or plas-tic. Cost of these units is somewhat higher than for the sink-on-a-drum, ranging from about $900 to $1,700. Filters and oilskimmers can also be added to these systems to increase theirefficiency.

Enzyme-Cleaning Systems

Hazards and Proper Handling: Replacement of VOC-con-taining solvents with an enzyme-based parts washer can elimi-nate most of the hazardous wastes from parts washing. A hand-wash brush is initially used to remove dirt or grime, using aflow-through nylon bristle design for manual cleaning. Thecleaning solution uses a neutral mixture of emulsifiers, surfaceactive agents, and microbes that do not contain VOCs, phos-phates, formaldehydes, biocides, or solvents for degreasing anddispersing oil from the small parts.

P2 Opportunities: With the combination of the closed-loopparts cleaner and the microbe-impregnated filter, the cleaningsolution does not require removal and replacement, so no wastesolution is generated.

Disposal and Regulatory Responsibilities: A hazardouswaste determination must be made on filter bags and sludgefrom enzyme parts washers. Characterizing a waste stream bytesting doesn’t have to be done on every filter or every timesludge is removed, as long as the process remains the same.This means if the filter is changed out after the same amount oftime, and the numbers and kinds of parts cleaned remain thesame during that time period, testing may only need to berepeated yearly or every two years.

Cost: Enzyme systems are generally modified sink-on-a-drumunits and are commonly made of plastic. They contain a spe-cially formulated surfactant-based emulsifying neutral enzyme

cleaner. Microbes are added to the system either through animpregnated filter or directly into the cleaning formulation.The cleaner emulsifies the oil and grease; the microbes break itdown to carbon dioxide and water. Like the sink-on-a-drumunit, the enzyme system has a heater and a pump. Units gener-ally have a 15- to 30-gallon liquid capacity. Cost of this type ofunit ranges from about $900 to $1,500.

Bake-Off Ovens

Hazards and Proper Handling: Bake-off ovens provide avery safe alternative to parts cleaning but are limited to partsthat are heat tolerant. The oven heats the part to a very hightemperature which “burns” the soils and oils off the parts.

P2 Opportunities: Bake-off ovens create little solid waste andare associated with fewer air emissions than solvent cleaning.

Disposal and Regulatory Responsibilities: The bake-off ashor residue waste stream should be characterized with a TCLPtest for heavy metals to determine if it is a hazardous waste.

Cost: Costs for bake-off ovens large enough for engine blocksand transmissions start at $7,500. These ovens operate between600ºF and 1000°F, use natural gas or propane, and cost approx-imately $2–4.00 per cycle of operation, depending on local fuelgas costs.

Use a Less Hazardous Solvent

Parts washing has typically used petroleum-based solvents inthe past to remove soils prior to working the part. Many ofthese solvents are considered hazardous because of their lowflash points and may contain compounds considered dangerousto the environment and human health. Compounds that containchlorine and other halogens have been identified as ozonedepleters and are associated with adverse health effects. Usinga less-toxic solvent is an important way to reduce pollution andreduce risks to employees. The following list identifies haz-ardous materials in solvents that should be avoided:

n carbon tetrachloride n tetrachloroethylene (perc)n methylene chloride n methyl ethyl ketonen trichloroethylene n xylenen toluene

If petroleum-based solvents must be used for parts cleaning,always use the least toxic material that will do the job, such asnaphtha, mineral spirits, or stoddard solvent. Always ask ven-dors for a material safety data sheet (MSDS) to inspect beforenew products are ordered or given to your shop for trial pur-poses, and make sure the vendor will take back the unusedproduct. This can reduce the amount of hazardous materialsyou may need to dispose of and keeps your inventory invest-ment to a minimum.

Printed on recycled paper

Maximize Solvent Life

No matter what type of parts-washer system you use, makingthe most of your cleaning solution is an integral step in pre-venting unnecessary material use and waste generation.Longer solution life means less cleaning materials used; themoney goes in your pocket, not down the drain.

Pollution Prevention Practices for Parts Washing:n Use the least hazardous method for cleaning.n Reduce aerosol can use; consolidate cleaning jobs and

materials used; use refillable, pressurized cleaning systemsfor on-the-vehicle cleaning needs.

n Always use the least toxic material—check material safetydata sheets before products are purchased.

n Establish sound operating practices to extendsolvent/cleaning solution life.

Shop Cleanup

The amount of waste generated in an auto repair shop is depen-dent upon the amount of spills or leaks created when workersdo their jobs. Wastes consist of floor dry compound, dirty rags,and water used to wash down the area. Good housekeeping isthe key to waste reduction. Prevent spills by providing drainpans with pour spouts to catch fluids removed from the vehicle.Bulk waste-fluid receptacles should be equipped with largefunnels and a drain-rack system to allow complete fluidremoval from catch pans. Small squeegees can be used toremove the remainder of fluids from drain pans if needed.Bulk containers should be equipped with a level gauge or pop-up level indicator to prevent overfilling, and secondary con-tainment should be provided to catch such spills should theyoccur. Waste from spills can be drastically reduced by main-taining a sound housekeeping policy with little or no invest-ment of capital.

When spills do occur, the following methods of cleanup shouldbe used to decrease the amount of waste generated:

n Use a large squeegee with an oil-resistant dustpan to get asmuch liquid off the floor as possible. This simple tool canall but eliminate use of floor dry materials, is reusable, andallows the fluid to be captured for recycle. When all fluidhas been removed, biodegradable detergent and water canbe used for final cleaning. Wash waters should not bepoured on the ground or directed to a septic tank and later-al field system, but sent to a municipal sanitary sewer.

n For large spills, “oil mops” are available to use with mopbuckets to recapture spilled liquids.

n Use recyclable rags for cleaning purposes; this will reduceyour solid waste stream.

n Keep all raw materials and fluid recyclables in safe, well-marked storage areas with sealed floors, to avoid acciden-tal spills and soil contamination.

Set up a sound inventory program to reduce excessive purchas-ing, product use, and generation of outdated products.

Vendor information for the services and equipment describedin this fact sheet may be obtained by contacting the SmallBusiness Environmental Assistance Program at 800-578-8898.

Cleaning solutions and solvent life can be extended by fol-lowing these easy work practices:

n Mechanically clean as much soil off the part as possi-ble with a wire brush or reusable rag before putting itinto a parts washer.

n Determine level of cleanliness needed; don’t do exces-sive cleaning—it costs your shop time and money.

n Use cleaning solution until it loses its cleaning power;don’t change out solutions on a scheduled basis.

n Set up a two-stage cleaning system; clean parts in dirti-est solution first, then transfer to a final clean washer.

n Keep parts washers covered when not in use to reduceevaporative losses.

n Drain all parts thoroughly to reduce drag-out losses ofcleaning fluids; install a drainage shelf if necessary.

n Filter solution to remove contaminants and prolong lifeof cleaning solution.

n Remove sludge and free-floating oil from cleaning sys-tems frequently to extend solution life.

n Consider a solvent-recycle system to reduce solventpurchases; solvent stills start at approximately $2,000.Some vendors now lease these units.

Notice of nondiscriminationKansas State University is committed to nondiscrimination on the basis of race, sex, nationalorigin, disability, religion, age, sexual orientation, or other nonmerit reasons, in admissions,educational programs or activities and employment (including employment of disabled veter-ans and veterans of the Vietnam Era), as required by applicable laws and regulations.Responsibility for coordination of compliance efforts and receipt of inquiries concerning Title VIof the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, Section 504 ofthe Rehabilitation Act of 1973, the Age Discrimination Act of 1975, and the Americans WithDisabilities Act of 1990, has been delegated to Clyde Howard, Director of Affirmative Action,Kansas State University, 214 Anderson Hall, Manhattan, KS 66506-0124, (Phone) 785-532-6220; (TTY) 785-532-4807.

This publication was created by Kansas State University’s PollutionPrevention Institute through the Small Business EnvironmentalAssistance Program (SBEAP). SBEAP’s mission is to help Kansassmall businesses comply with environmental regulations and identi-fy pollution prevention opportunities. SBEAP is funded through acontract with the Kansas Department of Health and Environment.SBEAP services are free and confidential. For more information, call800-578-8898, send an e-mail to [email protected], or visit our Website at http://www.sbeap.org. Kansas State University is an EEO/AAprovider.