Gov. Rendell yesterday sent a strongly worded letter to the U.S. Environmental Protection Agency objecting to a new rule that exempts two Montgomery County manufacturing firms from reducing their emissions of a suspected carcinogen, trichloroethylene.

He said he was "troubled the EPA believes exposure . . . at current levels is an acceptable risk."

Rendell contended the exemption "was never even considered an option in the proposed rule and is completely inappropriate and unacceptable."

The two plants, Superior Tube Co. and Accellent Inc., both in the Collegeville area, emitted the sixth- and eighth-highest amounts of TCE in the nation in 2005, the latest year for which such data are available.

In January, the state Department of Environmental Protection disclosed that two air monitors near Collegeville detected TCE levels five to 10 times higher than the average at the state's other monitors. It said the amount could raise the cancer risk in the surrounding area by as much as 1.6 people per 10,000.

The state has reached a voluntary agreement with both companies to reduce their emissions, although critics wanted a binding, enforceable agreement.

Accellent is installing equipment that would reduce emissions by at least 30 percent, perhaps as much as 90 percent. Superior also is switching technologies that would result in a 30 percent reduction in emissions this year, and at least 60 percent later.

The EPA had proposed reductions that would have required the companies to reduce their emissions by about 90 percent. But when the rule was finalized April 16, it exempted manufacturers in the "narrow tubing sector," which includes both firms.

The two companies make extremely thin metal tubing - some as tiny as a human hair - that is used in products ranging from coronary stents to the rovers that went to Mars. The tubing must be greased to keep it from breaking, and TCE is used to clean off the grease.

An EPA spokesman said last night the agency would "review the governor's letter and respond as soon as possible."

According to an EPA statement issued Thursday, such companies were exempted because "the technology doesn't currently exist to reduce emissions from this sector. EPA will conduct another technology review for this sector in eight years."

Rendell said in a statement yesterday the voluntary reductions proved that "stronger emissions standards for TCE are feasible and affordable." He also said he was "grateful" for the companies' "commitment to protect public health despite EPA's exemptions."

According to a DEP statement, both companies have said they would continue with their plans to reduce emissions, regardless of EPA actions.

Charles McPhedran, senior attorney for Citizens for Pennsylvania's Future, which has members in the Collegeville area, said the group had viewed federal limits on emissions as a vital backstop.

"The question for us, we had hoped, was how much better we could do with DEP action or citizens' direct action," he said.

Contact staff writer Sandy Bauers at 215-854-5147 or