Minnesota legislators are considering a statewide ban on the solvent trichloroethylene following revelations that a White Bear Township manufacturer vented the carcinogen into the air at unsafe levels for more than a decade.

It's a rare crackdown.

Even though the U.S. Environmental Protection Agency classifies the chemical as a human carcinogen and a developmental toxin — and it's been largely banned in the European Union and Sweden — trichloroethylene (TCE) is still widely used in the United States.

In Minnesota, at least 80 manufacturers and other entities still rely on the solvent, long seen as a good, cost-effective degreaser for metal, according to the Minnesota Pollution Control Agency (MPCA). The list of major emitters includes many manufacturers but also several utilities, Barnesville High School, St. Gabriel's Hospital and St. John's University.

The Senate version of the TCE ban, which has a Republican author, had a committee hearing Wednesday and is being revised. A companion bill has been introduced in the House by Rep. Ami Wazlawik, DFL-White Bear Township.

National environmental groups tracking TCE say they aren't aware of any state that has banned it, although some states ban its use for vapor degreasing, according to Tasha Stoiber, a senior scientist at the Environmental Working Group. But they applaud efforts to restrict it.

"It's in the top 10 chemicals that we worry about," said Jennifer Sass, a senior scientist at the Natural Resources Defense Council in Washington, D.C.

The EPA was on the verge of banning TCE from use as an aerosol degreaser and a spot remover at dry cleaning operations but shelved the plan in December 2017. That's now on the agency's "long term action" agenda.

"Banning any chemical is incredibly difficult," said Stoiber at the Environmental Working Group.

TCE triggered a wave of local concern in January, when the MPCA said it was investigating excessive airborne emissions by a White Bear Township manufacturer called Water Gremlin. The company, which makes fishing sinkers and electrical contacts for batteries, used TCE to coat its battery leads to prevent corrosion. Water Gremlin was by far the largest TCE emitter in 2017, state data show.

The Minnesota Department of Health has been investigating the emissions and has fielded scores of calls and e-mails from neighbors with concerns about their health. The department cannot make direct links between TCE exposure and the health complaints but suspects that the TCE concentrations were too low to cause much harm, said David Jones, a Department of Health research scientist supervisor. TCE dissipates quickly in the air.

"Our best understanding of the worst case is that the risk should be low," Jones said.

The contamination appears to have been limited to air emissions; there is no evidence of groundwater contamination, although health officials want to sample some nearby private wells to be sure.

Water Gremlin has replaced TCE with a less toxic solvent called FluoSolv as part of its recent $7 million settlement with Minnesota, which included a $4.5 million civil penalty. The company must also work on a program to educate manufacturers about eliminating or reducing TCE.

Following Water Gremlin, the biggest emitters of TCE were Viking Drill & Tool, Greatbatch Medical and Larsen's Manufacturing and Co-operative Plating — all in the Twin Cities.

The MPCA asks facilities with state permits to report all their air emissions of volatile organic compounds, including TCE, every three years. In 2017, the 80 facilities pumped out more than 130 tons of the solvent, state records show. Nearly half came from Water Gremlin. Water Gremlin was far exceeding what its air pollution permit allowed, regulators say, but much of the recorded pollution from other entities was likely legal and covered by permits.

Regulators, however, can't say for sure how much TCE gets emitted into the air. Not all facilities make the reports, and those issuing smaller amounts aren't asked to.

Kari Palmer, supervisor of the MPCA's risk evaluation and air modeling unit, said the agency is taking a closer look at TCE emissions "to see if there are any other concerns."

The Senate proposal would broadly ban TCE in the state. The first version of the bill says it would prohibit TCE from use "as a vapor degreaser, an intermediate chemical to produce other chemicals, a refrigerant, or an extraction solvent or in any other manufacturing or cleaning process or use."

The bill's lead author, Sen. Roger Chamberlain, R-Lino Lakes, said he is working with state pollution regulators to fine-tune the ban. In an interview, Chamberlain said the target is large and midsize users, not small ones or individual consumers. The ban would probably be phased in over two to three years.

"We want to ban the mass use to prevent any of these sorts of exposures that they had at Water Gremlin," Chamberlain said.

The MPCA, which has spent years trying to coax companies off TCE, supports the proposal.

Even some industry players appear to be on board.

At the Senate committee hearing Wednesday, Tony Kwilas, director of environment and natural resources policy for the Minnesota Chamber of Commerce, expressed no objection. He said he's working with lawmakers on the bill and wants to make sure businesses have enough time to determine the availability, cost and effectiveness of alternatives.

Committee members also heard from Sheri Smith, who said she can see the Water Gremlin plant from her house. In tears, Smith testified that neighbors had "considerable and profound concern" about unknown health impacts.

"I've lived in my home, one quarter mile from this plant, for 18 years and raised my three children at that home," Smith told lawmakers. "It's too late for our community, but we're asking that you ensure this doesn't happen to others in the future."

Jennifer Bjorhus • 612-673-4683