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.
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.
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.
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.
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.
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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.
Environmentally Preferable Purchasing Guide published by the Solid Waste Management Coordinating Board, 4/00. The SWMCB includes members from the Minnesota metropolitan counties of Anoka, Carver, Dakota, Hennepin, Ramsey, and Washington, with ex-officio members from the Minnesota Pollution Control Agency.
Last Revised April 18, 2008 - 9:31am