Overview

In the course of routine cleaning, many shops use parts washing systems for engines and other equipment parts. Parts washing systems include standardA characteristic or set of characteristics for an item, generally accepted by the manufacturers and users of the item as a required characteristic for all such items. recirculating parts washers, distillation units, and those with multiple filters. In choosing the right parts cleaning system, shops should evaluate both the equipment and the cleaning solvent it uses.

Start by determining the needs of your shop. The right choice will be a combination of system and cleaner that is safe, effective, and convenient while minimizing unnecessary costs. With parts washing services, seek out an appropriate level or frequency of service; also important are its record-keeping and management services that assure regulatory compliance.

Whether water-based (aqueous) or petroleum-based, cleaning solvents present their own environmental concerns. Along with the waste produced during usage, cleaners often pose exposure risks to employees. In most instances, shops must manage wastes produced during parts cleaning as hazardous.

By investigating regulations first, workplaces can avoid costly testing and compliance problems later. Weigh the pros and cons: a water-based system, for example, may avoid the need for an expensive parts washer service contractA solemn agreement between parties, usually written, with binding legal and moral force, usually exchanging goods or services for money or other consideration., but testing and approval from the agency responsible for wastewater treatment facilities (typically, Metropolitan Council Environmental Services in the metro area) is required prior to disposal down the sanitary sewer. The Minnesota Pollution Control Agency (MPCA) and metro counties have guidelines for evaluating and managing the potentially hazardous solids and filters from parts washers.

Laws & Guidelines

The laws and regulations that apply to parts cleaning wastes include Minnesota Hazardous Waste Rules, Minnesota Statutes, and federal regulations.

Before deciding on a parts washing system, know the regulatory advantages and disadvantages of each type. Whether aqueous- or petroleum-based, waste parts washer solvent must be managed as hazardous waste - unless an evaluation determines that the waste is non-hazardous. Waste evaluations may consist of knowledge regarding the chemical ingredients in the cleaner and the contaminants introduced to the cleaning solutions during cleaning; sometimes, additional testing may be necessary. If your parts cleaner service or supplier does not address regulatory concerns that apply to your parts washer, consult with your hazardous waste regulatory program for assistance.

Each of the metro counties has a hazardous waste program. In Greater Minnesota, the Minnesota Pollution Control Agency has staff available for assistance. Failure to gain the necessary approvals prior to disposal of parts cleaning wastes can result in enforcement action and other liabilities.

Performance

There are several different parts washing systems. Determine which system is best for your shop based on the type of parts that are routinely cleaned, as well as the type and amount of grime on the parts.

First, decide whether you need a parts washer. Some small engine repair shops have eliminated the need for their parts washers: instead, they directly apply small amounts of cleaners to small engine and other parts, and then wipe them clean with rags. The rags are later laundered and reused.

If you need a parts washer, decide what parts washing system and solvent you will require. System types range from standard recirculating parts washers and distillation units to units with multiple filters. Additional consideration should be given to the size of the parts to be cleaned, the dirtiness of the parts, and the frequency with which the system will be used.

After identifying a parts washing system, choose a cleaning solvent. Solvents are either aqueous- or petroleum-based.

Aqueous-based solvents
These water-based solvents are usually less hazardous to the user than their petroleum-based counterparts. They clean by using a surfactant (such as soap or detergent), a corrosive or alkaline ingredient, or another type of chemical to remove soil from parts. Although water-based cleaners are often touted as being "nonhazardous," "sewerable," or "environmentally friendly," they must be managed as a hazardous waste unless the waste has been evaluated and found not to exhibit hazardous characteristics. It is important for users of parts washers to understand that the solvent is water-based and that no other fluids except greases and oils are added.

Petroleum-based cleaners
Most petroleum-based systems use mineral spirits, Stoddard, or similar petroleum-based solvents. Exposure to concentrated vapors from these solvents can cause breathing problems and headaches. These solvents are also ignitable. Cleaners with higher flashpoints (>140°F) are available to reduce the risk of ignition. Shops using petroleum-based cleaners must take extra precautions when using and storing the product and managing the wastes.

Availability

There are many different kinds of equipment, cleaners, and services, including simple "sink on a drum" equipment employing Stoddard solvent, spray cabinets and services that lease equipment and collect waste cleaners. Equipment is available to purchase or lease through both manufacturers and local distributors. Cleaners are available through vehicle maintenance supply outlets, equipment manufacturers, and dealers. Parts cleaner collection services are available statewide through environmental service companies. There is also a state contract for purchasing aqueous parts washing equipment.

Cost

Equipment and Parts Cleaner Services
Equipment and service costs vary according to equipment type and service level. Equipment can be leased or purchased. Disposal of used cleaner can be included in the equipment servicing contract or handled separately.

Some parts washers, such as those with filters and skimmers, extend the bath life of the cleaner so that less is used. This saves money on replenishing supplies and disposing of old cleaner.

Aqueous-Based Cleaners
Although aqueous cleaners cost more per gallon than petroleum-based cleaners, they generally last 25% to 50% longer. Aqueous cleaners can therefore reduce consumption and disposal. Because they must be heated in order to be effective, electricity costs are higher than with petroleum-based cleaners.

Specifications

Specifications for parts cleaning equipment, cleaners, and services vary depending on the types of parts you are cleaning, amount and type of grime you are trying to remove, and the volume. See Performance. When writing specs for a parts washer, include a preference for equipment with two-stage cleaning and a recirculating feature with built-in filtration to continuously remove dirt and contaminants. If you are purchasing equipment that utilizes aqueous-based cleaners, also include a preference for equipment with a skimmer to remove oils and other floating contaminants.

Vendors

Minnesota State Contracts
There is a state contract for purchasing automatic parts washers that use aqueous-based less-toxic cleaners. See Cooperative Purchasing Venture for information on accessing this contract.

• S-833(5) Service: Aqueous Parts Washers

Other Equipment Vendors
To find equipment manufacturers and distributors, conduct an Internet search using the words "parts washers."

Aqueous-based Cleaners
The Minnesota Technical assistance Program (MnTAP) lists supplies in its fact sheet titled "Aqueous and Semi-aqueous Cleaners for Metal Parts degreasing." To access this fact sheet and additional resources on aqueous-based cleaners and suppliers, contact MnTAP at 612/624-1300 or 800/247-0015 to receive a copy.

Parts Washing Services
In the Twin Cities metropolitan area, call your county hazardous waste office (see Resources and Web Sites) for a list of parts washing services. Outside the Twin Cities, call the MPCA at 800/657-3864.

Resources

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