Are stronger nation-wide controls on worker exposure to trichloroethylene (TCE) likely in the near-future? Recently, the U.S. EPA held an “Expert Public Workshop on Alternatives and Risk Reduction Approaches to Trichloroethylene (TCE) Use as a Degreaser.” I participated both as an attendee and as a presenter. I suggest that you review the workshop whether or not you use trichloroethylene (TCE) or other aggressive solvents in vapor degreasing or in cold cleaning applications because a similar regulatory approach could be used to highly restrict – I hesitate to say ban – any number of effective process chemicals. Regulatory concerns aside, I suggest look over the presentations for their technical content, because there are some good options for both water-based and solvent-based cleaning – of course, you have to assess them for applicability in your own situation.
The day and a half workshop was held at the end of July as part of the EPA’s residual risk assessment for TCE. The risks that were addressed were not environmental exposure. Instead, the EPA focused on risks to employees in small businesses, notably manufacturing facilities, both to those working directly with TCE and to other employees in the same workplace. Risk considerations include sensitive populations such as pregnant people.
Substitution
Based on many of the presentations and comments, there may be stronger “encouragement” to use aqueous cleaning chemicals and/or flammable solvents for critical cleaning or precision cleaning. There was a rather forceful contingent among the presenters who took the position that TCE substitution is necessary and readily achievable, so that continued use of TCE would be unnecessary and unacceptable. The cleaning chemistries proposed in those case studies emphasized aqueous cleaning agents and flammable solvents. In fact, there were verbal assertions that lack of a flashpoint could be considered a marketing ploy and that people would have to “adjust” to flammable solvents, because that was what was available. One comment was that customers indicated that they were more concerned with cost and performance than they were with flammability.
Process change is tough
Friends, colleagues, and clients (a number of you are all three!), as you may be aware, I am concerned with all aspects of worker safety. I am concerned with the residual risk of replacing a well-controlled aggressive cleaning solvent like TCE with a poorly-controlled low flashpoint solvent or with a chemical or blend where the toxicological properties have not been well-documented. While I have published a number of case studies over the years, in my presentation I cautioned that, in general, negative results are not published. Therefore, extrapolating from a few success stories to a general victory over use of a particular solvent is misleading and counterproductive. In fact, as the last speaker of the program on day one, I took the opportunity to describe less than beautiful cleaning process conversions, including some that I had heard presented as success stories at other meetings.
That being said, case studies can provide guidelines as to how to proceed with process change. The approaches described by Wayne Ziegler from the Joint Services Solvent Substitution Working Group (JS3) in a Keynote and in a breakout session and by Jason Marshall and Heidi Wilcox of the Toxics Use Reduction Institute (TURI) are worth reviewing. I agree that process change can be difficult and that hand-holding is important; I’ve been known to bring milk and cookies to process change meetings. Technical data from controlled studies and cost analyses help, too.
Can we shift the paradigm a little bit?
I think it would be far more productive for regulators to take a process approach rather than a chemical by chemical approach. I remain concerned that the EPA continues to take a chemical by chemical “witch hunt” approach to regulation. It won’t work. I have been in the field for nearly 30 years (yikes!); and the “old timers” used to tell me about regulatory admonitions to stop using whatever “bad” chemical was under scrutiny; so maybe my “tribal knowledge” goes back for half a century.
In fostering solvent substitution, saying that there have been “unfortunate substitutes” is a good start, but it is not sufficient. Those of us involved in careful, responsible manufacturing know that there are often ways of managing flammable solvents and there are often ways of managing aggressive solvents. However, the answers are not simplistic; and they typically are not expressed in a simple table of “bad” chemicals and “suggested” substitutes.
Just imagine
Solvent substitution is, at best, an interim solution. I am a very proud recipient of the U.S. EPA Stratospheric Ozone Protection Award. The award was for solvent substitution; in actuality, my activities with the teams involved in replacing ozone depleting substances (ODS) involved process substitution. Most of the ODS substitutes were VOCs and/or flammable solvents. Developing, testing, and controlling the processes were greater challenges than substituting one chemical for another. I would love to see the EPA develop a more comprehensive, holistic award.
From the perspective of the United States, I think we need regulatory consistency and logic at the Federal level, because workers throughout the U.S. should not be exposed to different levels of hazards depending on where the factory is located. What if Federal agencies like EPA, OSHA, and the FDA communicated with each other, coordinated with each other, and took a holistic, process-oriented approach? We are more likely to minimize hazards to the worker, better protect the environment, produce better product, and have a more sustainable manufacturing environment.
Go to Docket EPA-HQ-OPPT-2014-0327 for all presentations and other supporting documents.
