n-propyl bromide, acceptable in solvent cleaning
Barbara Kanegsberg, BFK Solutions
A final rule: n-propyl bromide (nPB) is acceptable
as a substitute for ozone depleting compounds when used as a cleaning solvent
in industrial
equipment.
The rule has been issued by the Significant New Alternatives Policy Program
(SNAP) of the U.S. EPA. This long-awaited ruling is important where aggressive
solvency is required.
The new SNAP rule applies when nPB is used as a cleaning solvent in equipment
like vapor degreasers, automated “cold cleaning” equipment
(i.e. industrial cleaning equipment below the boiling point), and in-line
systems.
nPB is a non-flammable, brominated solvent. It has solvency characteristics
somewhat similar to that to the late-lamented 1,1,1-trichloroethane (TCA),
a compound that was phased out of production in the mid-1990’s because
it destroys stratospheric ozone (upper ozone, good ozone – not smog
producing ozone). nPB was originally submitted for SNAP approval in the mid-1990’s;
and it has been the subject of controversy ever since. Some of the controversy
is of the “political chemistry” variety. That is, considerable
roadblocks to the approval of nPB emanated from some producers, suppliers,
and advocates of other solvent or aqueous options.
As with any aggressive solvent, you should use nPB prudently to minimize
worker and community exposure; and you should educate your employees
in appropriate chemical management. The SNAP document outlines worker
exposure
concerns
without indicating a specific worker exposure level. While the SNAP
program does not regulate uses such as pails, sink on a drum, manual
dip tanks,
and squirt bottles, in our opinion it would be irresponsible to use
nPB or any
aggressive solvent without good controls. A well-controlled cleaning
system tends to end up costing less and results in higher quality.
Quality, of
course, encompasses product quality, worker safety, and environmental
safety.
The final rule document can be found at
http://www.epa.gov/fedrgstr/EPA-AIR/2007/May/Day-30/a9707.pdf
