Should you be a squeaky wheel or avoid making waves? Invest a moment to review a new U.S. EPA NESHAP that covers halogenated solvents in cleaning and two recent U.S. EPA announcements about n-propyl bromide (nPB). The new NESHAP may impel modifications in cleaning processes using chlorinated solvents. For nPB, there is a final rule indicating acceptability of nPB in cleaning applications. In other nPB applications, there is a proposed rule indicating unacceptable uses; it may be prudent to evaluate the options and advantageous to providecomments to the EPA.
NESHAP
There is a final “National Air Emission Standards for Hazardous Air Halogenated Solvent Cleaning.”1Your business may need to evaluate and adapt the cleaning process. The NESHAP, effective May 3, 2007 and building on the earlier 1994 standard, sets facility-wide emissions limits for new and existing solvent cleaning processes for per-chloroethylene (PCE), trichloroethylene (TCE), and meth-ylene chloride (MC). In Table 1, notice that allowable emissions levels differ for the three solvents because they are based on health risk assessments; PCE level takes into consideration analysis developed in California.
Please notice that three major groups are exempt from the new limits and a fourth has higher limits. Why? In part because people spoke up; they communicated with the EPA. These groups effected changes based on technical and economic arguments. The EPA’s consideration to emphasize airless (vacuum) cleaning systems was taken off the table based on upfront and ongoing costs, as well as decreases in capture efficiency. However, in our experience, there are applications where vacuum systems are a practical, effective choice. Even in traditional, open-top systems, by requiring well-controlled systems and careful recordkeeping, requirements of the new NESHAP have the potential to positively impact quality as well as profitability.
nPB
Within the U.S. EPA, the Significant New Alternatives Policy Program (SNAP) evaluates acceptability of replacements for ozone depleting compounds. N-propyl bromide (1-bromopropane, nPB) was submitted to the EPA as a replacement in the mid-1990s; a partial ruling is finally available (Table 2). There isa final rule and there is a new proposed rule.
For the solvent cleaning sector, there is a final rule2determining nPB to be an acceptable replacement. However, the EPA proposes3to list nPB as unacceptable for aerosols, adhesives, and most durable coatings applications citing data indicating risks to worker health in those applications and noting the availability of alternative chemicals.
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SQUEAKY WHEELS
The Halogenated Solvent NESHAP and the SNAP Ruling covering nPB used in cleaning are pretty much “done deals”; the appropriate response is to adapt or modify critical and industrial cleaning processes. However, in terms of the proposed rule for nPB, you (meaning you as an individual, a business,or an association) have an opportunity to comment to the EPA.
Should you be a squeaky wheel? It may be in your best interest. In an earlier discussion of the NESHAP, the EPA had asked for input ONLY from four manufacturing areas; and those areas ended up with higher limits or no limits. However, as suggested in an earlier “Point of View,”4businesses that could be impacted by the NESHAP or by any other impending regulation have a fiscal and environmental responsibility to communicate relevant issues to the EPA, whether or notthe EPA asks for those comments.
In addition, notice that in the proposed nPB rule, only one application was proposed to be acceptable for durable coatings; this was for the Army installation that submitted comments. The EPA proposes to allow this single forthright Army installation to use nPB for durable coatings; others wanting to use nPB for similar applications would have to submit individual SNAP proposals, proving to the EPA that they could achieve similar worker exposure levels. The requirement to submit separate SNAP applications seems a bit cumbersome.
Even if you think the nPB proposals will not impact your in-house manufacturing processes, we suggest that you check with your supply chain. Determine if the proposed alternatives to nPB for aerosol coatings, adhesives, and durable coatings provide viable options. For example, you might want to ponder the alternative products listed for aerosol applications such as PCE, TCE, MC, and other water-based products and blends. We are a bit concerned about the relative safety, effectiveness, and the availability of suggested alternatives; and we would like to see emissive uses of all chemicals revisited. For your own applications, we suggest that you consider the performance attributes, known and unknown toxicity profiles, and other environmental constraints of the alternatives. Then, whatever your decision, communicate by speaking up — write to the EPA. Perhaps you can suggest approaches to minimizing the impact of all emissive solvents and blend using — what was that term? Oh yes — “controlled environments.”
In the proposed rule, the EPA invites comments on alternative control strategies that they considered but rejected (Read the proposed rule; this will make more sense). An alternative to “unacceptable” for all applications would require frequent or periodic monitoring of employees and documenting that no tested employee is exposed to over 20 ppm in an 8-hour time-weighted average (TWA).
Perhaps your position is “don’t make waves” with the EPA. Well, in our view, a successful business means making a profit, being in a favorable competitive position world-wide, and maintaining quality. Quality refers to product performance, worker safety, and environmental considerations.
We therefore respectfully suggest that to be a successful manufacturer, expunge the fear; prudently and clearly communicate with the EPA. We should still be within the comment period for the nPB Notice of Proposed Rulemaking when this issue of Controlled Environments is published. So go over to your computer, compose your thoughts, hit the tact key. Vit-riole is counterproductive; you want waves, not a Tsunami. Get your comments to the EPA NOW. Manufacturing requirements are complex. The EPA cannot read your mind. Better communication is more likely to produce optimal regulations. Thoughtful technical input to the EPA from you will yield superior, encompassing quality.
References
- Federal Register publication of the Halogenated Solvent Cleaning NESHAP: http://frwebgate3.access.gpo.gov/cgi-bin/ waisgate.cgi?WAISdocID=36332611581+0+1+0& WAISaction=retrieve.
- Final EPA SNAP nPB rule for solvent cleaning: http://www.epa.gov/fedrgstr/EPA-AIR/2007/May/Day-30/ a9707.pdf.
- Proposed EPA SNAP nPB rule for aerosols, adhesives and durable coatings: http://www.epa.gov/fedrgstr/EPA-AIR/2007/May/ Day-30/a9706.pdf.
- B. Kanegsberg, “Point of View: Morning Workout,” Controlled Environments Magazine, February, 2007. Available at http://www.cemag.us/articles.asp?pid=661.
Barbara Kanegsberg and Ed Kanegsberg are independent consultants in critical and precision cleaning,surface preparation,and contamination control. They are the editors of The Handbook for Critical Cleaning,CRC Press. Contact them at BFK Solutions LLC., 310-459-3614;[email protected];www.bfksolutions.com.
