Several solvents used in parts-cleaning operations — such as methylene chloride (MEC),
perchloroethylene (perc), and trichloroethylene (TCE), and n-propyl bromide (nPB) — are
all filed under “Risk Evaluation” by the U.S. EPA under the Toxic Substances Control Act
While some manufacturing facilities continue using nPB for vapor degreasing in partscleaning operations, time may be running out for the use of those solvents as regulators at
the federal and state level are beginning to look at banning or severely limiting those
solvents’ uses. The EPA announced in 2016 that 10 chemicals — including methylene
chloride, perc, TCE, and nPB — would undergo “Risk Evaluations,” the second step in EPA’s
existing chemical process under TSCA.
The purpose of the evaluation is to determine whether a chemical substance presents an
unreasonable risk to health or the environment under the conditions of use. As part of this
process, EPA must evaluate both hazards and exposure, exclude consideration of costs or
other non-risk factors, use scientific information and approaches in a manner that is
consistent with the requirements in TSCA for the best available science, and ensure that
decisions are based on the weight of scientific evidence.