Special to Plant Services

Pollution-free parts washer breakthrough: Bioremediation (click here for full article)

A new generation of water-based parts washers cleans like solvent but eliminates fire and health hazards, legal liability, EPA paperwork, skimming, gray water hauling and hazardous waste disposal.

By Thomas W. McNally, General Manager, ChemFree Corporation, www.chemfree.com. 8 Meca Way, Norcross, GA 30093 770 564 5581, tmcnally@chemfree.com

There are more than one and a half million parts washers in America—many of them in industrial plants. These sink-like units are often fitted with pumps, brushes and sometimes work lights. Most are filled with a solvent that can clean grease and dirt off machine parts. For generations, the solvent parts washer has been a fixture in American industry wherever there’s machinery to maintain. It’s a low-tech tool that’s done its job and attracted little attention-- until recent years. A company’s parts washing operation, once exclusively the province of the maintenance manager, is emerging as a matter of concern for the company’s risk manager, the environmental compliance officer and even legal counsel. Under these growing pressures, the solvent parts washer is clearly headed the way of leaded gasoline.

Deteriorating air quality, growing EPA oversight, increasing health concerns and a general litigiousness have focused closer scrutiny on industrial solvents. Improved measurement techniques and a growing body of data have uncovered disturbing facts about mineral spirits and other low-flash solvents once presumed to be relatively innocuous.

New evidence of solvent health risks.

Numerous studies have discovered unsuspected health consequences of solvent exposure. One such study, Solvents and Neurotoxicity by White and Proctor, published recently in The Lancet, the leading British medical journal, reported that workers exposed to even moderate amounts of airborne or skin-absorbed solvent may be affected by fatigue, depression, confusion, attention deficit, memory loss, tingling, numbness, loss of smell, muscle weakness and irritability. Exposure symptoms generally seem to affect the central nervous system and heretofore were not linked to solvents. Long term exposure was found to produce irreversible symptoms including cognitive and behavioral changes, impotence, skin irritation and even cancer.

Soaring Legal Costs of Solvent Use

This growing proof of the health risks associated with a wide variety of solvents

has precipitated a number of lawsuits holding employers liable for employees’ and citizens’ solvent-related health problems and fire risk. The supporting science is so complex and pivotal that the costs of defending against such claims can be enormous. One highly visible such case is the celebrated Woburn, MA, suit, subject of the best selling book, ‘A Civil Action’. In this case, generally considered a ‘victory’ for the defendants, the corporations will ultimately pay fines and fees into nine figures and have suffered enormous negative publicity. In another solvent-related case, a group of Lockheed Martin employees exposed to various solvents over a span of years were initially awarded a nine-figure compensation by a jury. Solvents can be expensive.

Cradle-to-grave Liability

Solvent from a parts washer can be classified as hazardous waste and any company that generates hazardous waste is required to file meticulous records—records that may be made available to the public and the press. As a hazardous waste generator, a company bears responsibility for that waste until it’s rendered harmless. That means a corporation using a traditional solvent parts washer could be charged with penalties and clean-up expense even after that solvent waste has been removed by a licensed waste handler. If the waste hauler’s truck turns over on a busy highway or if they fail to process that waste properly, the generating company may be forced to pick up the tab. Even a clerical error or omission in the complex EPA hazardous waste documentation can lead to fines and penalties.

Local governments ban or limit the use of solvent parts washers

In an effort to curb ozone air pollution, the EPA has established strict air quality standards and Federal Department of Transportation funding is linked to compliance. Local governments, facing the withdrawal of federal highway funds are forced to impose draconian measures that could include limiting the use or the outright banning of solvent-based parts washers. A solvent parts washer generates volatile organic compounds (VOC’s) comparable to the annual emissions of ten automobiles. In January, 1999, solvent parts washers were banned from the four county Los Angeles basin. In September, 1999, air quality management officials in the San Francisco bay area instituted strict limitations on solvent parts washers. Chicago, St. Louis and East St. Louis officials have followed suit and many other local government bodies are contemplating similar restrictions.

The search for an alternative to solvent-parts washers.

In recent years, a number of water-based parts cleaners have been introduced. They effectively eliminate many of the liabilities of solvents. However, non-bioremediating aqueous parts washers present their own set of problems. They require regular skimming of oils that must be disposed of according to EPA guidelines. They generate gray water that also requires special disposal at regular intervals. Perhaps most important, they don’t handle certain greases very well and their efficiency drops off the longer the fluid is used.

Bioremediation comes of age.

Scientists have long known that certain microbes could break down complex hydrocarbons like oil into its components—water and carbon dioxide—without hazardous intermediaries. This class of microbes was used effectively in cleaning up the Exxon Valdes oil spill in Alaska’s Prince William Sound. Scientists called this process ‘Bioremediation’, the breaking down of hazardous materials into harmless components through the use of living organisms.

Developing a parts washer to employ bioremediation proved a challenge. A surfactant cleaning fluid was used to remove the grease and oil from the part and microbial action was used to digest the oil removed. The problem was to develop a surfactant that would clean a very dirty part but wouldn’t kill the organism and to develop a vigorous and voracious organism that would break down the oil but not attack the surfactant. That problem was solved by a patented process and the emergence of a new generation of surfactant/degreasers that provide a congenial environment for microbial growth. Some are pH-neutral, nonflammable, aqueous-based combinations of chemicals that contain no hazardous components that could harm workers or interfere with biological development. What’s more, some of these cleaning agents can handle even impacted fifth-wheel grease and other lubricants that defy ordinary water-based cleaners. New strains of robust microbes can now survive through a wide temperature range.

As a result of these advances, bioremediating, water-based parts washers can be found in tens of thousands of applications world wide. They are used in every branch of the armed services and have been embraced by many of the worlds largest, best run corporations e.g. Ford, Daimler-Chrysler, BMW, Lockheed Martin, Boeing, 3M, Bridgestone/Firestone and Reynolds Metals. .

How bioremediating parts washers work

In the most advanced bioremediating parts washers, the process begins when the surfactant/degreaser cleaning agent in the fluid breaks the bond between the contaminants and the part itself, lifting off the dirt like a liquid spatula. The contaminants are carried by the cleaning fluid through a filtering device, or mat, where particulate matter as small as 50 microns is captured.

The fluid flowing through the mat releases a combination of microbes and nutrients into a holding tank positioned below the mat. The microbes released into the fluid and now living and multiplying in that medium produce natural enzymes which cleave the molecular bonds in hydrocarbon molecules—grease and oil. The fluid cleans the part and the microbes clean the fluid. This action releases water which dissipates in the fluid and ultimately evaporates. The process also releases carbon, a nutrient for the microbes. The organisms come to life in this closed loop system and ‘eat’ the oil and grease leaving the fluid clean and potent as new. The fluid is re-circulated from the bottom of the parts washer tank so that there is no interruption in the cleaning process.

The filter/mat is changed once a month. The used mat with the particulates it has captured are usually disposed of as harmless solid waste. The replacement mat with its cargo of fresh microbes assures a vigorous colony in the cleaning fluid.

Temperature is important in maintaining a bioremediating system. Fluid in the holding tank should be maintained at approximately 105° F—about bath water temperature. This temperature is comfortable to the touch and aids in the cleaning process by raising the efficiency of the cleaning fluid. It also provides the optimum environment for microbial reproduction and digestive processes. If fluid temperature drops, say in a power outage or during movement of the parts washer, the microbes become quiescent but return to their previous vigor and effectiveness when warmed.

Straining out solid particles before they reach the holding tank eliminates the principal components that form sludge. A properly maintained bioremediating parts washer has virtually no odor and need never be emptied-- simply topped up to replace fluid lost through ‘walk-away’ and normal evaporation.

The microbes themselves have an impressive pedigree— carefully bred to be champions at eating the stuff that would poison our environment. Yet they’re harmless as the family retriever. There is no genetic manipulation involved and, since the organisms are isolated from natural sources, they are defined by the Toxic Substances Control Act (TSCA) as ‘naturally occurring’ -- safe as potting soil.

The Benefits of Bioremediation

A properly maintained, bioremediating parts washer offers many advantages over traditional solvent parts washers and even over non-remediating water-based parts washers.

The bioremediating parts washer requires no EPA record keeping, no hazardous waste hauling or disposal and incurs no cradle-to-grave liability. No exposure to EPA fines, no penalties or cleanup charges. It presents no health or fire risks.

While ordinary water-based parts cleaners loose their effectiveness as the fluid is contaminated, the bioremediating parts cleaner always operates at high efficiency. What’s more, the bioremediated fluid is comfortable and safe to touch, never caustic and it needn’t be skimmed of oil or disposed of as gray water.

Many users of the leading bioremediating system report that the direct cost of operating their new parts washer is actually less than their traditional solvent washer even before factoring in the costs of record keeping, hauling, disposal and potential liability.

Today’s maintenance manager is buffeted by many complex forces—cost efficiency, hazard management, government regulation and legal liability. The step to a bioremediating parts washer can simplify life and move the beleaguered manager outside that maelstrom—at least in his parts washing operation.

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About the Author

Tom McNally is vice president and general manager of ChemFree Corporation. He is an inventor on several patents, pending and allowed, for processes and designs incorporated into the ChemFreeâ Smart Washerâ , a bioremediating parts washing system marketed worldwide. Mr. McNally attended Hamilton College in Clinton, NY, and graduated from Old Dominion University in Norfolk, VA. He also serves as chief executive officer and a director of Microbial Aquatic Treatment Systems (MATS), an emerging technology company in the phytoremediation field.