TANSTAAFL Barbara Kanegsberg, BFK Solutions

TANSTAAFL
Barbara Kanegsberg, BFK Solutions

Peripheral neuropathy related to exposure to blends containing n-hexane was found in workers in automotive repair facilities. In one facility, the aerosol product contained 1% to 5% n-hexane and 2% MEK. One comment* provides food for thought:

“The neurotoxic effects of n-hexane may be intensified when used with other chemicals found in automotive degreasers (e.g., acetone, MEK, and isopropanol)”

In the article, the suggestion is made to avoid hexane-based cleaning solvents, reformulate the products and make greater use of aqueous cleaning systems. However, I would add that as most of us realize, aqueous cleaning is appropriate for many, but certainly not for all applications. In my opinion, the study also indicates that we must be watchful (not paranoid, but watchful) of all newly adopted and seemingly effective blends, even blends containing primarily relatively benign chemicals. As you may be aware, when Perchloroethylene was eliminated from brake cleaners in California, other blends were adopted, including blends containing acetone and n-hexane.

TANSTAAFL
“There ain’t no such thing as a free lunch.” (R. A. Heinlein, “The Moon is a Harsh Mistress”) We often include a “no free lunch” overhead in our educational programs. We explain that everyone wants a solvent or cleaning agent that removes all the soil, does not damage the substrate (the material you are trying to clean), has absolutely no impact on the environment, and is completely safe for workers. This is, to say the least, a highly improbable set of circumstances. We all contain organic chemicals, water, and some other minerals and inorganic chemicals. The same holds for the environment. The same holds for the parts and components we are trying to fabricate, clean, or coat. The bottom line is that any chemical or blend that is effective in industrial or critical cleaning applications also has the potential to damage the environment or to present hazards to workers and to those in surrounding communities.

When we evaluate cleaning chemistries for particular applications, we often run into blends that have unexpectedly high efficacy for soil removal – the whole performs better than the sum of the parts. In some cases, we see impacts on plastics and elastomers. When we see higher than expected efficacy of cleaning, even if we don’t see problems with materials compatibility, we advise clients to use the products with caution. The reason: there is no free lunch. In all cases, we suggest controlling the process, not just controlling the chemical.

We continue to postulate that TANSTAAFL is an unavoidable aspect of effective critical cleaning. However, if you invest in a controlled process, the investment can yield dividends.

To achieve acceptable, competitive performance, we have to refine and optimize the process. There are good quality-related reasons to control the process: environmental quality, employee protection, and product quality. In most cases we find that controlling the emissions of cleaning chemistries and other process chemicals also results in better product quality. Improved product quality results from using the chemical only where you need it and under optimal, minimally emissive conditions.

*R. Harrison et al., “n-Hexane related Peripheral Neuropathy Among Automotive Technicians California, 1999 – 2000,” MMWR Weekly 50(45):1011-3, Nov. 16, 2001

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