A West Virginia judge has found that a chemical used to make Teflon is toxic and has punished DuPont for destroying documents as it defends itself in a class-action lawsuit involving the chemical.

The lawsuit was filed in August 2001 on behalf of as many as 50,000 people who live near a DuPont plant along the Ohio River, including residents in West Virginia and Ohio who drank from contaminated public water supplies.

The latest ruling orders the company to pay for blood tests to measure exposure to ammonium perfluorooctanoate, also known as C8.

The ruling also orders DuPont to pay the plaintiffs’ attorney fees and other costs for delays in providing some company documents and destroying others.

DuPont has until late May to appeal the ruling. In a written statement, the company said that the chemical doesn’t pose a health hazard and that the ruling was based on “erroneous and meritless” claims.

“Nothing in DuPont’s 50 years of experience with C8 indicates it is a hazard, and nothing in the toxicity for C8 suggests the class members (plaintiffs) are at any risk whatsoever,” DuPont attorney Larry Janssen said yesterday in a written statement.

But Wood County Circuit Judge George Hill said in his May 1 ruling that people near the plant were “unwittingly exposed” to the chemical from the plant.

Hill also called C8 “toxic and hazardous to humans.”

A Cincinnati attorney representing the plaintiffs declined to comment. Bob Griffin, general manager of the Little Hocking Water Association, said he hopes the ruling will answer questions about the extent of his customers’ exposure.

“It’s in the blood of people nationwide, apparently,” Griffin said. “It’s a question of whether it’s more here than elsewhere.”

Last month, the U.S. Environmental Protection Agency launched a scientific study of the potential health hazards of the chemical.

It has been used for more than 50 years to produce household products that resist water, grease, stains and other chemicals.

The EPA inquiry came after C8 was found in drinking water in Ohio and West Virginia and in the blood of DuPont workers. Studies by DuPont and 3M, once the leading manufacturer of C8, found the chemical in human blood nationwide.

It’s unclear how the chemical is finding its way into people’s blood. Possibilities include exposure to air or water contaminated during the manufacturing process, or contact with consumer products that have been treated with the chemical.

Levels of C8 in the blood of people living near the plant could be 1,000 times higher than the general population, according to calculations based on a study DuPont published in 2001. The company now says the study was flawed.

Judge Hill ruled the company should pay for blood tests to measure exposure levels.

He also ruled that DuPont had ignored court orders to make records available.

In a letter to the judge, DuPont acknowledged that Gerald R. Kennedy, the company’s lead toxicologist on C8 issues, had destroyed “written and electronic documents” about the chemical.

Hill asked the plaintiffs’ attorneys to submit expenses incurred because of DuPont’s violations of evidence rules and court orders. DuPont, the judge ruled, will be required to reimburse them.