MnTAP Fact Sheet: Removing Solvent and Ink from Printer Shop Towels and Disposable Wipes

Background Information

Shop towels and disposable wipes that are contaminated with excess solvent and ink pose significant risks to the environment if they are sent to a landfill or commercial laundry facility. This is because:

• If the solvent and ink-contaminated towels are sent to a commercial laundry facility, the excess solvents and inks are washed out into the wastewater. This can create dangerous conditions in sewer lines as well as pass through municipal wastewater treatment plants. These contaminants can then end up in our lakes, streams and rivers.

• If contaminated disposable wipes are put in the dumpster, they pose a hazard due to the flammability or toxicity of many solvents. In addition, the contaminated wipes could end up in a landfill where the solvents may leach into the groundwater. Cleaning up the resulting groundwater contamination is costly and complicated. Your company may be held liable for the contamination and may be required to pay for clean-up costs.

Management of Shop Towels Sent to Commercial Laundry Facilities

If you do not remove excess solvents from shop towels, they must be managed as a hazardous waste and must not be laundered. However, management techniques can be used to remove excess levels of solvents and inks from shop towels so they can be sent to an authorized commercial laundry facility. Three options used to accomplish this are listed below.

NOTE: The following options will not be effective without the involvement of employees in suggesting how to make changes, and a successful and repeated employee training program.

Option 1: Change Clean-up Procedures.

• Eliminate the practice of using solvent-soaked towels to clean rollers.
  
• Use equipment that limits the ability of workers to soak towels in solvent before they are used to clean ink from roller blankets. This includes plunger cans that moisten but do not soak towels, and squeeze bottles that moisten towels by limiting the amount of solvent that can be easily soaked into a towel. Squeeze bottles also can be used to apply solvent directly to the roller blanket.
  
• Limit access to solvent.
  
• For each press, distribute a limited amount of solvent for clean-up each workday. Provide equipment like squeegee bottles or plunger cans to employees to help them limit the amount of solvent used for each clean-up. To make this work effectively, employees need to understand why limiting the use of solvent will yield potential benefits for everyone.

  Note: One Minnesota company that recently limited solvent usage for each press has realized $100 savings per day in solvent purchases.

• Establish procedures to prevent dumping liquid solvent and ink waste in used towel containers.
  
• Make it easy for employees to collect solvent and ink waste:
  
  1. Explain to employees that liquid waste cannot be added to towel containers, and that towels must not be used to soak up solvents and inks that collect in trays after roller blankets are cleaned.
     
  2. Place a drum or container for solvent and ink waste close to the containers used for towels. This drum or container should be clearly identified and labeled and have a large enough opening to allow solvent and ink waste to be easily poured from long collection trays. When not being filled, liquid storage drums must remain closed.
     
  3. Fabricate a special chute that allows easy transfer of solvent or ink that is collected in trays on raised platforms to a drum on the floor below.
     
  4. On one end of each solvent collection tray, drill a hole, install a drain fitting, and attach a hose through which the solvent or ink can be drained into a container. It is easier to transfer the solvent or ink to a storage drum from the container than from the collection tray.

• A hand-operated wringer (or a mop wringer) can be used to remove excess solvent and ink.

  Note: Make certain that the rollers are made of solvent-resistant material.

  Place the separated solvent and ink in a closed container and handle as hazardous waste. Label the container clearly so that employees don't mistake solvent and ink waste for water.

• An explosion-proof centrifuge can be routinely used to separate most of the solvent and ink from the towels. The centrifuge must be explosion proof.

  Note: Currently only one company is known that sells such centrifuges, and the cost is in excess of $10,000. Local sales representatives are listed at the end of this fact sheet.

• If you do not have separation equipment, require that towels be hand-squeezed (using protective gloves, eye protection and adequate ventilation) to remove solvent and ink before they are placed in the used towel container.

• A parts washing unit with recirculating solvent can be used instead of towels to clean trays. Trays are removed from the press and placed in the washer unit where the solvent is used to remove the ink waste. A list of companies selling or leasing parts-washer units is provided at the end of this fact sheet.

  CAUTION: Make certain that the unit used has a large enough base support to prevent it from tipping over.

• A stream of solvent (for example, from a squeeze bottle) can be used to wash ink waste to one end of the tray equipped with a drain hole, a drain fitting, and a hose to drain the waste into a container. The solvent is then easily transferred from the container to a storage drum.

Management of Disposable Wipes

• Collect the soaked wipes in a drum and manage as hazardous waste. However, if wipes are contaminated with a solvent that is hazardous only for ignitability (D001 or F003), remove the solvent as described in procedures for towels that are laundered. Once the solvent is removed, the wipes can be managed as industrial solid waste (if approved by your local regulatory agency).

• Change to reusable cloth towels, and set up a procedure to remove excess solvent and ink waste as outlined above. Then the towels can be sent to an authorized commercial laundry facility.

• Limit access to disposable wipes and solvent for press clean-up. This will automatically result in a reduction in waste.

Other Considerations

The success of your company's program to reduce solvent and ink levels in towels or disposable wipes will depend on:

• Management's commitment to a workable solution.
  
• Employees' attitudes as well as their level of cooperation and commitment.
  
• The effect of changes in procedure or equipment on each employee's ability and ease to perform their work.
  
• Designation of an employee(s) with authority and responsibility for towels and solvent management.
  
• Repeat training provided with reasons for following procedures.
  
• Opportunities for employee input to improve procedures.

Note: To be successful in reducing your costs, your company must take steps to ensure that no wipes end up in the waste solvent storage drum. Towels or wipes can jam up a pump used at the recycling or disposal facility. Your company may be charged for losses to equipment and time, should this occur.

Equipment Information for Printers

The following list of equipment is maintained by MnTAP solely as a service to Minnesota companies. The information is voluntarily supplied and listed alphabetically. It is not necessarily a complete list of available services or suppliers and does not represent an endorsement by MnTAP. MnTAP, by providing the list, does not represent that the companies are or are not in compliance with applicable laws. All users of this list are responsible for insuring that any company with whom they contract for products or services with the requirements of state and federal law.

Description	Manufacturer	Local Sales Representative
Explosion-Proof Centrifuges	Bock Toledo, OH 43611 419/726-2645	BDS, Inc. Minneapolis, MN 55425 612/854-1801 or 800/328-1974 Bill Berndt
Hand-Operated Wringers*	Alden Industries New Orleans, LA 504/944-7681 (larger model; not hand-operated) Lab Safety Supply Janesville, WI 53547-1368 800/356-0783	BDS, Inc. Minneapolis, MN 55425 612/854-1801 or 800/328-1974 Bill Berndt Specialty Equipment Mendota Heights, MN 55120 612/452-7909
Parts-Washing Equipment Manufacturers	Graymills Corporation Chicago, IL 60613 312/248-6825 Kleer-Flo Eden Prairie, MN 55344 612/934-2555 ManGill Chemical, Magnus Division Cleveland, OH 44117 800/627-6422	Mike Woods Maple Grove, MN 55369 612/425-7890
Parts Washing Equipment and Solvent Leasing Service	Safety Kleen Elgin, IL 60123 800/669-5740 or 612/487-4181 Call for regional locations
Miscellaneous	McCarty Water and Waste Maple Plain, MN 55359 612/479-4343 COMMENTS: Mobile unit extracts solvent from your company's towels at your company's site with explosion-proof centrifuge. Rollins Oil Roseville, MN 55113 612/636-7990 COMMENTS: Provides pick-up service for some disposable shop towels. Shop towels must meet very specific conditions, mandated by the Minnesota Pollution Control Agency, and have solvent wrung out.
* Ask the company selling the wringer if the rollers are made out of the same material as the blankets on printing presses. Regular "rubber" on wringers does not stand up to the solvents used to clean blankets.