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)”
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
