DuPont Co. will have three additional years to complete key tests of whether the toxic chemical C8 is leaching out of consumer products, under a deal finalized during the final month of the Bush administration.

U.S. Environmental Protection Agency lawyers agreed to extend DuPont’s deadline – originally set for Dec. 27, 2008 – for three more years.

The new deadline is Dec. 27, 2011, under an order approved Jan. 8 by the federal Environmental Appeals Board.

DuPont had agreed to conduct the tests as part of a deal to settle a lawsuit brought by the EPA. Federal officials had alleged that DuPont hid from the public and regulators important information about the dangers of C8 and related chemicals.

C8 is another name for perfluorooctanoic acid, or PFOA. It is one of a family of perfluorinated chemicals, or PFCs.

“I think outraged would be the word I would use,” Olga Naidenko, an Environmental Working Group scientist, said when asked to comment on the new EPA-DuPont deal. “These experiments should have been done a long time ago.”

Bob Nelson, a DuPont spokesman, declined comment Thursday afternoon.

In West Virginia, DuPont has used C8 since the 1950s at its Washington Works plant south of Parkersburg. C8 is a processing agent used to make Teflon and other nonstick products, oil-resistant paper packaging and stain-resistant textiles.

Around the world, researchers are finding that people have C8 and other PFCs in their blood at low levels. People can be exposed by drinking contaminated water, eating tainted food, or through food packaging and stain-proof agents on furniture or carpet.

Evidence is mounting about the chemical’s dangerous effects, but regulators have yet to set a binding federal limit for emissions or human exposure.

Last month, a scientific paper published in a European journal found that levels of C8 already found in the general population’s blood might be linked to reduced fertility in women.

In December 2005, DuPont agreed to pay $10.25 million in fines and spend $6.25 million on “supplemental environmental projects” to settle a C8-related suit filed by the EPA.

Government lawyers alleged that DuPont had for 20 years covered up key data about C8’s health effects and about the pollution of water supplies near the Washington Works plant.

Specifically, the EPA alleged that DuPont never told the government it had water tests that showed C8 in residential supplies in concentrations greater than the company’s internal limit. Also, the EPA alleged that DuPont withheld for more than 20 years the results of a test that showed at least one pregnant worker from the Parkersburg plant had transferred the chemical from her body to her fetus.

As part of the deal, DuPont agreed to spend $5 million on a project designed to investigate the potential of nine of its fluorotelomer-based products to break down into C8. Fluorotelomers are chemicals applied to food packaging, stain-resistant clothing and carpet protection. They include brand names like Teflon, Zonyl, Stainmaster and Scotchgard.

At the time, the EPA said the project “will help industry, scientists, the public and EPA examine the potential sources of PFOA in the environment and potential routes of human exposure to PFOA.”

In a joint motion filed in late December, DuPont and the EPA told the Environmental Appeals Board that DuPont needs more time to complete the project.

The deal with the EPA also gives DuPont additional time to start a “green chemistry” program in the Wood County school system.