nPB, TCE, & PERC Replacement - Considerations in Alternative Selection

As you have heard the EPA risk assessment studies have determined the use of 1-bromopropane (nPB) Trichloroethylene (TCE), Dichloromethane (Methylene Chloride) and Perchloroethylene (Perc) as “unreasonable risk to human health” when used as a vapor degreasing solvent, as well as a majority of the other industrial uses for these solvents were used for. In December 2020, the State of New York banned the used of TCE for vapor degreasing effective December 1, 2021.

When you consider the New York action along with previous rulemaking in California and Minnesota against the use of TCE, the long-term viability of TCE nationally seems dire. Now is the time to consider alternative degreasing methods. The outcome of your decision on what is best for your site will take time to implement.

What are the solvent replacement options to be considered? Here are a few options as I see them, along with some considerations.

  1. Hope for some EPA waiver for my specific industry allowing continued use
    1. Based upon the data presented by EPA this seems highly unlikely.
  2. Forgo vapor degreasing all together
    1. Evaluate- “why do we degrease our parts?” Is vapor degreasing of parts a “must”, “like to”, or “wish to”. Is it in-process clean or final clean?
    2. If vapor degreasing prior to aqueous cleaning, conduct a study how the removal of this preclean step will affect your alkaline cleaner. My experience says absolutely review this thoroughly, there will be cause/effect.
    3. How does the removal of vapor degreasing affect the next step of the process? As importantly as how does it affect the process before vapor degreasing. Will changing the oil used for machining or stamping give you more flexibility. (The answer to this question determines the next steps.)
  3. Send parts to someone else for vapor degreasing
    1. Logistics: time, distance
    2. Work in progress: timing, cost
    3. Relying on someone else to meet your cleaning spec- assuming you have one in place that is documented.
  4. Purchase carbon absorption equipment and continue using
    1. Engineering controls are in place currently under NESHAP. Enhancement of these options is unlikely
    2. Not possible with nPB due to thermal breakdown and acidity issues
  5. Convert to a fluorinated vapor degreasing solvent using existing equipment
    1. Lower boil points may not remove some soils such as waxes which are temperature sensitive in their removal
    2. Higher vapor pressure of the solvent may increase solvent loss during operation and idling. “We know we have some leaks” will be exacerbated.
    3. Similar results for standard manufacturing oils
  6. Purchase a new vapor degreaser made for fluorinated solvents
    1. Cost of new equipment
    2. Lower boil point issue from above
    3. The new machines are very efficient in solvent recovery vs existing/old vapor degreasers
  7. Decide to convert to aqueous cleaning
    1. Cost of new equipment
    2. Handling of water from incoming to waste; wash and rinse
    3. Drying of parts
    4. Learning the intricacies of a vastly different process
    5. Can provide equal or better cleaning results
  8. Decide to convert to vacuum vapor degreasing (Airless)
    1. Cost of new equipment
    2. Waterless degreasing with hydrocarbon, modified alcohol or fluorinated solvents
    3. Similar degreasing results

I do not see a clear winner from these options that manufacturers will settle on. This was the same type of disruption that occurred when the EPA banned CFC’s in the 90’s. We are fortunate that technology in the cleaning business has made great strides in the past 30 years. The fluids and equipment technology shift have been driven by nonstop advancements in manufacturing and end user requirements for better products. Suppliers of products in the cleaning industry have been forced, rightfully so, to make advancements and keep up with manufacturers requirements.