Solvent Management Best Practices for the Printing Industry

Employees in the printing industry can be exposed to multiple solvents in their work environment.

These solvents, while effective and often required for the job, can also pose serious health, safety, and environmental risks.

This article explores ways to better manage your solvent through a series of best practices in solvent reduction, handling, and recycling.

These best practices can improve employee health and safety, support your sustainability initiatives, reduce costs, and support compliance, such as VOC mass balance reporting.

Getting Started

A good place to start is with a solvent inventory. Document every solvent in use or in storage.

Keep records of all solvent purchases, including:

• Product name
• Manufacturer’s information, including Safety Data Sheets (SDS)
• Where and how the solvent is stored
• How much you use for particular jobs
• How much you return as waste
• How much you recycle or recover
• How much evaporates
• How much leaves in water or other means

Implement inventory control by preventing uncontrolled access and distribution of solvents.

Your solvent inventory and on-site observations will help lay the groundwork to develop objectives and measurable targets for safety, solvent reduction, and mass balance reporting.

Because some of your workers may encounter solvents frequently, they may not give much thought when it comes to solvent safety. Ensure that everyone who works with solvent is properly trained on how to use, store, and handle solvent at your facility and clearly understands the hazards (outlined below) associated with them.

Choosing the Best Solvent

Choosing the right solvents for your needs involves a number of factors including price, function, safety, and environmental impact. In addition to minimizing all of the risk factors discussed below, the solvent needs to work well for the task.  If a solvent does not work well, too much may be used, or additional cleanup materials may be needed, wasting time, money, and resources.

Work with your supplier to make the best choice.  Investigate use of solvents with low volatile organic compounds (VOCs) or solvent alternatives such as detergent or soap, nonhazardous blanket washes, and less toxic acetic acid solvents. Identify the disposal/recycling implications of choosing one chemical over another.

Everyone wants environmentally better options. That would mean – no brominated, chlorinated or fluorinated solvents and no solvents that contain Hazardous Air Pollutants (HAPs).

If possible, purchase solvents from a company that will pick up and recycle the used solvent.

Be careful with free samples. If they turn out not to meet your needs, you will be left with the problem of disposing of them. Ask the vendor to take back any unused samples. Be sure to get the SDS for all samples and trial materials.

Mass Balance Reporting

A Solvent Management Plan can be used to estimate VOCs emissions based on solvent inputs and
outputs, according to the following principle:

The sum of all solvent inputs = The sum of all solvent outputs (including emissions into air)

Inputs are often easily estimated, and include any purchased solvents and recovered or recycled solvents. On the contrary, only some outputs can be easily estimated.

Solvent outputs can include:

• Total emissions (ELV), which can include waste gases that have been captured in abatement equipment or stacks, as well as fugitive emissions that may have escaped to the outside environment via windows, doors, vents and similar openings.
• Solvent lost in water
• Solvent that remains as residue on the product
• Solvent collected for waste or recovery
• Solvent-contaminated wipes

Safety & Health considerations

Respiratory

When using solvents, health impact is measured in terms of toxicity ratings. These usually are called TLV (Threshold Limit Value), PEL (Personal Exposure Limit), AEL (Assigned Exposure Limit) or similar terms.

Solvents that become vapors are generally assigned PELs that define how much can be present in the air and still be a safe work environment. The lower the PEL, the more dangerous the particular solvent is.

TLV is the level to which a worker can be exposed day after day for a working lifetime without adverse effects.

While many solvents have strong, unpleasant odors that serve as a warning sign, others are completely odorless and colorless, so you may not even be aware of the exposure. Even in cases where there’s no immediate damage, inhaled solvents can accumulate in body tissue and cause long-term damage to organs and systems. What’s more, the solvent may affect your judgment or awareness, increasing the chance that you’ll have an accident.

Your best defense against solvent fumes is a properly ventilated workspace.

Skin and Eye Protection

Dermal exposure to solvents can result in a variety of occupational diseases and disorders, including occupational skin diseases (OSD) and systemic toxicity.

You should monitor the OSHA recommended and regulatory limits for all solvents in your inventory.  Your insurance company or outside contractor can assist you if needed. PPE, such as a respirator, gloves, apron, fire retardant clothing, and safety glasses, should be provided as needed. SDS are a good source of information on the type(s) of PPE recommended by the manufacturer. Be sure to follow all NFPA, OSHA and manufacturer recommendations.

Fire and explosions

One of the biggest hazards of any solvent is the potentially flammable vapors. The most dangerous can be explosive. Generally speaking, the greater a solvent’s volatility (the rate at which it changes from a liquid to a vapor), the greater its flammability.

It’s important to know the flashpoint of solvents used in the work area. The flashpoint describes the temperature at which enough vapors are being released so that a spark or a flame could ignite the vapors.

According to OSHA, flammable liquids have a flashpoint below 100°F. Combustible liquids have a flashpoint at or above 100°F and below 200°F.

While most workers know not to smoke or use open flames around solvents and their storage areas, they may not realize some of the other dangers that can arise – like static electricity.

When you transfer a solvent from one container into another, for example, static electricity could build up and create a spark and ignite any vapors. To prevent this, it’s a good idea to ground metal containers. This pathway helps the static electricity safely dissipate into the ground. Another method is to use anti-static equipment or static dissipaters.

Both the National Fire Protection Association (NFPA) and the Occupational Safety and Health Administration (OSHA) have bonding and grounding requirements.

Safety & Health Tips Roundup:

• Ventilation: Your best defense against solvent fumes is a properly ventilated workspace. Either general or task specific exhaust ventilation (or both) may be used to provide protection. General ventilation is used primarily to bring fresh air into the workplace and dilute the solvent, while task specific exhaust ventilation removes the vapors from confined workspaces and specific areas.
• Grounding: Ground metal containers when solvents are being transferred from or into them if they have a high flashpoint.
• Storage: Solvents and solvent-contaminated-wipes should be stored in separate, sealed containers that have been designed for them, and placed in well-ventilated, fire-resistant areas that have appropriate fire extinguishers available within reach. According to the EPA Wipes Rule, you may not store soiled wipes or towels on-site for more than 180 days. Work with a certified laundry or waste handler to properly reuse or discard solvent-contaminated wipes.
• PPE: PPE, such as a respirator, gloves, apron, fire retardant garments, and safety glasses should be provided as needed.
• Training: Workers and on-site contractors need to be aware of all the solvents being using on the jobsite, the steps they can take to protect themselves, and what actions should be taken in the event of a solvent spill or injury. Follow all safe handling information provided by your supplier.
• Minimize Risks: Eliminate ignition sources such as sparks, flames, static electricity and excessive temperatures. Minimize spilling, splashing and spraying of solvents being transferred; for example, transferring liquid into a tank. Keep containers of solvent and solvent containing items closed when not actively filling or emptying.

Solvent Reduction

A good solvent plan will include methods to minimize solvent use.  Once you know what you are using and how often you are using it, you can effectively track your reduction strategies.

As part of your management plan, review automated solvent dispensers to be sure they are operating as intended. Review how employees are using solvent in their everyday tasks; spray, drip, wipe, dip, flush. Is regular preventive maintenance being done? Is the right chemical used for the task? Are wipes put in the correct container? Are wipes wrung after use?

Careful planning and some extra employee training can reap huge benefits – improved health and safety, reduced costs, pollution prevention, and less regulatory compliance, to name a few.

Here are some helpful tips on how to reduce your solvent usage:

• Use solvents only for cleaning inks and oils. Use alternative products for all other cleaning.
• Use job scheduling to reduce press clean up by running lighter colors, and then darker ones, whenever possible to reduce cleanup waste volume.
• Dedicate presses to specific colors or special inks to decrease the number of cleanings required for each press.
• Consider installing automatic blanket washers to reduce the amount of solvent used and wastes generated.
• Avoid soaking towels in solvent at that process or application.
• Use pumps or squeeze bottles with proper fit to dampen towels. Wring after use and recover at your facility.
• Remove excess ink from surfaces or equipment with a scraper or spatula before wiping with a shop rag.
• Use spot application of solvents for stubborn ink residues rather than over application of solvent to an entire area.
• Squeegee or wipe surfaces clean before washing with solvent.
• Use precise measuring and pour in a funnel to reduce splashing or spraying.
• Keep storage containers tightly closed and away from heat to avoid evaporation  and pressure buildup.

Solvent Reuse

If solvent must be used, get creative with ways the solvent can be reused.  If reused, the solvents are not considered to be wastes and, therefore, are not regulated.

Here are some ideas:

• Gravity drain or mechanically wring saturated shop towels to remove excess solvent; recover as much solvent as possible for recycling.
• Reuse spent solvent for other cleaning, such as mopping. Start with the cleanest need and work your way to the dirtiest need.
• If you must pour solvent over a roller, use a drip pan underneath to collect the solvent that falls beneath.
• Use recirculating solvent sinks for parts cleaning.
• Place catch basins around the screen during screen reclamation in order to capture chemical over spray.
• Partner with a towel cleaning service to clean and recycle the solvent from your solvent-contaminated wipes.

Storage, handling, and disposal

Workers should follow all guideline for how to safety store, handle, and discard solvent and solvent-contaminated wipes.

Work with your suppliers or a third party to properly recycle or discard spent or unused solvent.  How to determine if solvents are a hazardous waste.

Your solvent contaminated wipes are not considered a hazardous waste if you follow all of the guidelines in the EPA Wipes Rule, which can be regulated both by EPA and your state agency.

Some of the basic guidelines in the EPA Wipes Rule include:

• Label all in-house and transportation containers with “excluded solvent contaminated wipes” labels
• Have a written description of how free liquid is kept out of transportation containers
• Know that your laundry has a permit for wastewater discharge
• Wring towels out before placing in any container
• Keep lids closed on all containers of solvent contaminated towels
• Consciously use only what you need

Training & Communication

A good solvent management plan is only as good as the training and communication to support it.  Put process controls in place to limit access to solvents, and ensure that every worker that uses solvents or solvent-contaminated-wipes has the proper training.

Reinforce your training with clear signs that support best practices, PPE requirements, and warnings.

Additional Resources