Making tiny specialty steel tubes for use in
products like heart stents takes a lot of precision, but the
manufacturing process generates a lot of friction.
For years, two narrow tube manufacturers in
Pennsylvania have used trichloroethylene (TCE) in their
manufacturing process as a solvent during the degreasing phase
after the lubricated tubes are drawn down to smaller and
smaller sizes, often with a wall thickness of just a few
thousandths of an inch. The highly toxic solvent was leaking
into the air, however, causing health concerns among residents
and the Pennsylvania Department of Environmental Protection
Superior Tube Co. Inc. and Accellent Inc.,
both in Collegeville, near Philadelphia, have invested
considerable time and money in research and development to
rectify the situation. No fines or penalties have been imposed
on either company, the DEP said.
Superior Tube completed reformulation and
degreaser removal projects that are expected to reduce TCE
emissions by more than 50 percent this year. The company also
plans to eliminate TCE from its manufacturing process and
replace it with n-propyl bromide (nPB), an alternative approved
by the U.S. Environmental Protection Agency. Unlike TCE, nPB is
not considered an air toxic.
Accellent chose to install two carbon
absorber units to control TCE emissions from its large
degreasers. The company began operating its first unit last
October. While the absorber equipment manufacturer guarantees
emission reductions of 35 percent, the DEP believes that is a
very conservative estimate. Emissions reductions of 90 percent
or greater can result from this type of installation, according
to the DEP.
The state agency is already seeing results.
Recent data from a stationary air monitor near Collegeville in
Evansburg State Park shows that levels of airborne TCE are
diminishing, with many days registering no measurable levels.
That trend is expected to continue, given the companies'
voluntary efforts to reduce emissions, the DEP said.
Tony Jost, Superior Tube's president and
chief executive officer, said his company has been working to
reduce environmental emissions for six years. "It's consistent
with our environmental policy of being a good corporate and
Jost said his company made emission
reductions in 1999 and again in 2002 and continued to
investigate further measures by teaming with its sister company
in Britain and with sources in the solvent industry. "There is
no shortage of experts to work with," he said. "There were
multiple things we explored using. The challenge was finding
something that you could use."
The company notified customers about the
potential for processing changes and assured them that the new
methods would still meet their quality demands, Jost said. "We
had to make sure we maintained the quality that our customers
have come to expect from us. We've studied the project for a
long time and (have) gotten as confident as we can without
compromising the quality of our products."
It's important to maintain metallurgical
properties and cleanliness since the tubes that Superior makes
must be highly pure, he said. In addition to medical
applications like heart stents, end-use applications for
Superior's products are in the aerospace and nuclear
"Our markets have no tolerance for any
issues," Jost said, declining to say how much Superior spent on
research and development and equipment modifications necessary
to use nPB, noting only that it was "a significant investment"
for the privately held company.
Engineering consultant Matson &
Associates Inc., State College, Pa., said in a report that nPB
is more expensive than TCE, pegging the cost of nPB at roughly
$3 a pound vs. about 70 cents a pound for TCE for large
industrial users, although most nPB users see a 5- to
20-percent reduction in solvent purchases after switching.
Lynda Rebarchak, the state DEP's community
relations coordinator, couldn't say whether Superior's or
Accellent's approach to reduce TCE emissions was the better
method. "We're technology neutral when it comes to these
things," she said. "It's up to the companies to figure out the
best way for the process they do and the different contracts
they have, whether that's FDA or military."
Superior had been under more pressure from
local residents after news that two small TCE spills occurred,
Rebarchak said. "Accellent was not under as much pressure, but
now with Superior switching altogether residents are now saying
they'd like to see Accellent switch, too."
According to the EPA, TCE exposure is
associated with several types of cancer and with health effects
ranging from headaches to liver damage. The DEP found TCE air
levels in the Collegeville area were significantly higher than
elsewhere in the state, putting area residents at a greater