Coping with Change in Critical Cleaning and EPA Amended TSCA Rules

“Survival of the fittest” is a tenet of Charles Darwin’s evolution of species as many United States manufacturers requiring critical product cleaning must develop survival strategies and tactics.

Note: Analysis and comments reflect the status as of August 31, 2024. Specifically, a final rule for MC has been issued and proposed rules for PCE, TCE and nPB (1-BP) have been published.

Barbara and Ed KanegsbergOne immediate source of this existential crisis are new and impending regulations from U.S. EPA Amended TSCA. The regulations restrict or even prohibit use of certain effective, aggressive chlorinated and brominated solvents in vapor degreasing and related activities. The most recent update is the proposed rule to manage n-propyl bromide (nPB). Manufacturers have only until September 23 to comment. Be aware that EPA refers not to nPB but to 1-bromopropane (1-BP). Manufacturers who want to survive should peruse the proposed 1-BP rule. Manufacturers who use or who have suppliers of components or product with cleaning processes that depend on Methylene Chloride (MC), Perchloroethylene (PCE) or Trichloroethylene (TCE) should peruse the 1-BP rule. The proposed rule provides possible paths forward for manufacturers. Understanding all the rules, all the different EPA strategies, will enhance your ability as a manufacturer to be among the “survival of the fittest.” 

What does “fittest” mean? In Darwinian terms, fittest does not mean the strongest; fittest does not mean the most intelligent. Fittest means the “most adaptable to change.” How might manufacturers adapt to changes impelled by EPA regulations? How much change is needed? What are the costs? In this article we discuss the proposed nPB (1-BP) rule AND compare it with the final rule for MC and the proposed rules for TCE and PCE. As principals at BFK Solutions, we intend to submit our comments to the 1-BP (nPB) docket.

nPB (1-BP)

On August 8, 2024, the Proposed Rule, “1-Bromopropane (1–BP); Regulation Under the Toxic Substances Control Act (TSCA)”, was published in the Federal Register (1). Under the proposed rule, everyone using nPB must change their cleaning processes or certify that their current processes meet EPA requirements. The primary concern with nPB, and with the other three solvents under consideration is worker exposure, not environmental releases. 

Staying below the worker exposure limit will be much more difficult than meeting an OSHA standard. The reason is that a few years back, the U.S. Congress passed what is usually referred to as “Lautenberg”(2) with bipartisan support. Under Lautenberg, EPA was tasked with eliminating “unreasonable risk” to not only to the environment but also to workers. EPA has established an Existing Chemical Exposure Level (ECEL). The ECEL is very different from limits set by OSHA or AGCIH (3) (Table 1). For a few, particularly those using nPB sealed, reduced pressure solvent systems, survival adaptation may be no more than providing a required “self-certification” that they currently meet EPA requirements for worker exposure. However, meeting those requirements is likely to be very challenging for most users. 

Table 1: Exposure levels for halogenated solvents

 *Short-Term Exposure Limit

nPB would be allowed in vapor degreasers. The ECEL for N-propyl bromide is 0.05 ppm. EPA asserts that a level of 0.05 ppm could be achieved. Frankly, based on our experience and because most manufacturers use nPB open-top degreasers, we find this blanket assertion to be – what’s the word? Curious, aspirational, perhaps unrealistic. The assertion that ECEL can be reached in most situations is not realistic. Certainly, there could be a few situations where the EPA assertion is viable. For example, in a small R&D group or a manufacturer with very low product throughput, a small open-top vapor degreaser could be placed in an area remote from employees and used once or twice a day for no more than 1 to 2 minutes.

Further, until recently, nPB was not listed as a hazardous air pollutant (HAP) and therefore did not have to be used in NESHAP compliant degreasers with increased freeboard. Spray wands are often used to access all surfaces of the part being cleaned. This means the employee is standing over the vapor degreaser and may spray solvent relatively close to their face. If the process is not automated, there will be high employee exposure. The levels achieved must be even lower than 0.05 ppm, because the proposed rule calls for an action level of 0.03 ppm. If the EPA has found examples of employee monitoring indicating successful control with open top degreasers, it would be enlightening for that data were to be made publicly available. 

We expect current nPB processes to be discontinued in most applications. Substitute processes would involve process change and/or chemical substitution.

Sealed, Reduced Pressure Cleaning Systems

Vapor degreasing in nPB ought not be prohibited. Assertions of compliance with an exceedingly low ECEL sets up false hope. The nPB proposed rule, and rules for MC, TCE, and PCE, should be revised to encourage and support cleaning process technology. The dream of solvent substitution as a solution is just that – a dream. Manufacturers use halogenated solvents not through ignorance or laziness but because they have the physical and chemical properties to clean effectively.

Rather than targeting individual chemicals one at a time, pathways to success ought to be suggested by EPA and encouraged by EPA. Manufacturers who make the significant financial investment in capital equipment, employee education, process development and process validation/verification should be encouraged and rewarded. EPA should work with other agencies to develop incentivization programs. 

nPB and similar solvents can be used in sealed, reduced pressure cleaning machines (often referred to as airless/airtight systems). For decades (probably since the 1980s) such systems have been successful to minimize releases of volatile chemicals. Their use should be encouraged and rewarded by EPA. We implore EPA to develop and post a category for such systems, as opposed to using the incorrect and misleading terms likely “sealed, enclosed, or closed-loop.” EPA might consider such systems as examples of BACT (Best Available Controlled Technology); or EPA might prefer another acronym. 

EPA needs an accurate, encompassing definition for such systems, one that includes differences in design. We refer Clean Source readers to our January 2024 article (4). One reason reduced pressure cleaning machines have not been recognized as adequate may be that those who manufacture or supply such systems seem to foster only their technology is acceptable. BFK Solutions has ZERO desire to head up an ASTM or ISO committee on the topic! Here is our fervent plea to providers of such systems: Stop (verbally) bashing each other over the head! Please stop saying only your technology works! In our observations, many similar technologies are acceptable. Help the EPA make critical product cleaning safe and effective.

Disparate Regulatory Approaches

Assessments and rule development under EPA amended TSCA have proceeded during the same timeframe and presumably using the same approaches. The rules/proposed rules for MC, PCE, TCE and nPB ought to look relatively similar. They don’t! (See Table 2)

Table 2: Differences, regulation of halogenated solvents

*Workplace Chemical Protection Program

As we will explain, the compliance pathway in the proposed rule for nPB is quite different and clashes with rules or proposed rules for MC, PCE, and TCE. Manufacturers who use MC, PCE, or TCE or who have suppliers using MC, PCE, or TCE should immediately comment about nPB and request harmonized, reasonable, and achievable rules for those solvents. 

Harmonized Rules Are a Must

The proposed rule for nPB handles solvent management and employee exposure in a far different manner than to analogous rules/proposed rules for MC, TCE, and PCE. In fact, each of the four rules take a different approach. Manufacturers will find adapting to the new rules to be more accessible if the rules resemble each other.

The ECEL for methylene chloride (MC) is 2 ppm – that’s 40 time higher than the ECEL for nPB. The final rule for MC categorically and, to us illogically, prohibits MC in vapor degreasers, not even in reduced pressure sealed systems. Granted, MC has a STEL (short term exposure limit). The presence of a STEL should not in and of itself be a barrier to using MC. To de facto prohibit such use seems to us to be an unwarranted example of in loco parentis for adult workers.

The ECEL for PCE is 0.14 ppm – that’s 2.8 times higher than nPB. The proposed rule for PCE does not provide a similar expectation that manufacturers could comply with the ECEL in vapor degreasing, even though one might expect lower emissions because the boiling point of PCE is somewhat higher than that of nPB, and even though, as a NESHAP solvent, PCE tends to be used in more modern, less-emissive degreasers. 

The ECEL for TCE is exceedingly low, 0.06 that of nPB. Vapor degreasing with TCE is generally prohibited, with an extended time for some NASA uses. WCPP self-certification is not proposed. It seems to us illogical to prohibit use of TCE, without providing a mechanism to demonstrate effectiveness appropriate engineering controls. Also, extended time exemptions of up to 10 years for NASA and defense uses seems highly unreasonable to us. Accepting that TCE is so highly dangerous, the lives of people working at NASA and at certain defense contractors should not be put in danger. If NASA and defense contractors can control exposure to TCE, why can’t the rest of us? And why does there have to be a 10 year phaseout time? In addition, why should only “the big guys” get extensions. Small medical device manufacturers also provide product that is “safety-critical”. We discuss “safety-critical” and other categories of cleaning a bit further down in this article.

Influence Change; Adapt to Change

We think manufacturers should take advantage of the opportunity to make comments to the EPA about all four solvents. Based on our interpretation of the proposed rule for 1-BP, the mechanism for making comments appears in Section VIII of the proposed 1-BP rule. In Section VIII, the ECEL for not only nPB about also for the other 3 solvents would be formalized in a different EPA document, including solvents where the comment period has passed and even where a final rule has been issued. We suggest that the rule for MC should be considered as cast not in concrete but in wet, mushy concrete – or, at least that’s what should happen. All you folks ought to speak up right away, to better protect the environment, employees, and U.S. manufacturing!

Changes in the cleaning processes are inevitable for many manufacturers. Changes may be impelled by new, more stringent customer demands on product quality or product performance. This includes new standards limiting contamination level. Becoming the fittest may involve becoming more cost-effective by replacing old, inefficient cleaning equipment with cost-effective processes that achieve reliable cleaning. 

Considerations associated with amended TSCA activities include the costs and aggravation in evaluating new equipment and developing and validating new cleaning processes. Your company or your customers’ company may institute policies that go beyond the EPA proposals and rules. Corporate policy may ban even a whisper of certain chemicals. Particularly with complex supply chains, “equivalent” cleaning processes that don’t really work as well may replace the tried-and-true aggressive solvents. This is exacerbated by the fact that chemical suppliers may elect to cease U.S. production; we have already seen this with trichloroethylene.

Regrettable Substitution

In the 1-BP proposed rule, we find a single use of the phrase “regrettable substitution” (Section IV(A)1biii). Most people consider the concept of “regrettable substation to be using an alternative chemical that then becomes subject to safety/environmental investigation. Flashpoint-inerted trans-DCE azeotropic blends contain chemicals that are or may be considered PFAS; and trans-DCE is itself under scrutiny by EPA amended TSCA. How long will they be available? Who knows. Given these considerations, these blends often considered a short-term substitute. They could be part of a good survival strategy depending on performance and the effort needed to validate the new process. Substitute chemicals and processes come with other risks to employee safety; and those risks are not sufficiently outlined or addressed. Flammability is a real issue. It can be managed. However, improperly handled, there can be risks to people and property. Many substitute chemicals and chemical blends have not been adequately studied.

Cleanliness Categories – Consequences of Not Cleaning

Other substitute chemicals are dissimilar to nPB, MC, TCE, and PCE. In general, the more dissimilar the chemical, the more process development will be needed. The regulations for the four solvents are so burdensome to most manufacturers that not-in-kind substitutes require more cleanliness and materials compatibility testing than do more closely related solvents. Examples of not in-kind substitutes relative the four halogenated solvents include hydrocarbons, modified alcohol, isopropyl alcohol, water and aqueous blends, HFEs and HFOs used without trans-DCE, d-limonene as well as “chemical free” processes (eg. steam, laser, or plasma cleaning). 

Particularly with not-in-kind substitutes, adaptation changes in the cleaning process that are impelled by EPA amended TSCA require substantial effort and investment. The amount of cleaning process development and testing depends on the negative impact of inadequate cleaning or not cleaning on the ultimate produce. Investment in new processes includes substantial testing for cleanliness verification/validation. 

When we teach or help clients, we often explain that process development, cleanliness testing, cleaning process validation is particularly crucial in areas where public safety, defense capability, and patient safety are issues. Some people refer to this type of cleaning as “Where Failure is Not an Option.” Because our background includes defense, aerospace, pharma, and medical device manufacturing, we teach the category where “if you don’t clean it right, airplanes and missiles fall out of the sky and patient’s asses fall off.” EPA has wisely chosen the far more elegant term “Safety/Critical Cleaning.” In the safety/critical category, unintended consequences to the product include ineffective unacceptable residue. Unintended consequences also include unforeseen, undesirable interaction with materials of construction and, in the case of medical devices with human biological systems.

Back in what we fondly recall as “The Great Freon Festival”, the EPA Significant New Alternative Policy (SNAP) Program was instituted to address use of Ozone-depleting Substances (ODS) that were phased out due to the Montreal Protocol agreement. The SNAP program, which is wide ranging and is active today, covers diverse areas like aerosols, refrigerants, fire suppressants, and cleaning. Under SNAP there are three cleaning categories, Metals Cleaning, Electronics Cleaning and Precision Cleaning. The three cleaning categories reflect the era when what became SNAP was being developed (starting in the 1980s). in the nPB economic analysis, EPA includes four categories of cleaning in the Economic Analysis Section 7.7 of the Economic Analysis for 1-BP (6)

We use a similar approach in teaching cleaning to students, practicing engineers, and professionals in process cleaning. We teach these four categories of cleaning (Table 3); more details are available in a publicly available webinar (5)

We suggest that the four categories be included in the final rule for 1-BP and in any revisions of rules for MC, TCE, and PCE. One reason is to avoid the consequences of “regrettable substitution” and “unintended consequences.” We suggest that “self-certification” by solvent users should include the category(ies) to which they need to clean as well as how they are approaching the requirements of the rule. We suggest that manufacturers requiring safety/critical cleaning be provided with additional time to comply with the regulation. We suggest that it is counterproductive and in our humble opinion dangerous to public safety and patient safety to push those manufacturers toward solvent substitution. The risks of “regrettable substitution” and “unintended consequences” are simply unacceptable!

Table 3: Cleaning categories

Adaptation

Adaptation is the key to survival. Here are some final thoughts.

• Be vigilant – be aware of impending changes.
• Submit comments to the EPA.
  • Change the cleaning process methodically and logically.
  • Use a team with the appropriate expertise, in-house and external. 
  • Be educated about the pros and cons of alternative cleaning processes. 
  • Run cleaning tests on your product. This includes waste management and cleanliness testing. 
  • Estimate the full costs of process conversion. Set up a budget. We almost guarantee you will underestimate the degree of effort (7). 
• Change your manufacturing plan to something that does not require cleaning.
• Move your manufacturing facility overseas. This adaptation comes with a high cost. 

Some adaptations are unwise

• Ignore the problem; and hope someone else solves it for you. This is unlikely in the long term. It’s more likely that bigger companies will move to areas in the world with less stringent regulations.
• Expect large companies and the military to protect you. “Special treatment” is evanescent and unreliable. Large entities protect themselves.
• Pick a cleaning process based only on sales claims. Don’t run cleaning tests.
• Assume that it won’t cost that much to change
• Stop manufacturing. This is a great strategy if you are independently wealthy and/or ready to retire. 

References

• https://www.regulations.gov/docket/EPA-HQ-OPPT-2020-0471/document , Docket EPA-HQ-OPPT-2020-0471-0032
• Frank R. Lautenberg Chemical Safety for the 21st Century Act, https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/frank-r-lautenberg-chemical-safety-21st-century-act
• Kanegsberg and E. Kanegsberg, “Degreasing and Fireworks”, Clean Source July 2022, https://bfksolutions.com/degreasing-and-fireworks/ 
• Kanegsberg and E. Kanegsberg, “Degreasers”, Clean Source January 2024, https://bfksolutions.com/degreasers/
• Kanegsberg, E. Kanegsberg, and D. Williams, Product Quality Cleaning Workshops (PQCW) webinar, Feb. 8, 2022, https://mailchi.mp/f358f1fd84c7/pqcwebinar-on-epa 
• US EPA, OPPT, “Economic Analysis of the Proposed Regulation of 1-Bromopropane Under TSCA Section 6(a)”, RIN 2070-AK73, Docket EPA-HQ-OPPT-2020-0471-0114.
• Kanegsberg and E. Kanegsberg, “What Can Go Wrong?”, presentation to The Surface Finishers Educational Association (SFEA), Nov. 11, 2021; https://www.youtube.com/watch?v=m1Pp06grbvk

Barbara and Ed Kanegsberg founded BFK Solutions in 1994 as a critical cleaning consulting service and the go-to resource to make cleaning, surface quality, and contamination problems go away or — even better — to avoid problems in the first place. Barbara, widely known as “The Cleaning Lady,” is an expert and trusted adviser in critical cleaning. Ed is known as “The Rocket Scientist,” they write Clean Source, an approximately monthly e-newsletter that provides practical ideas to improve cleaning, contamination control, and product quality. They are co-editors and contributors to the acclaimed two-volume “Handbook for Critical Cleaning,” CRC/Taylor & Francis, 2011. Visit https://bfksolutions.com