A Pleasant Hills man yesterday filed a federal lawsuit against military contractor KBR, saying that the company knowingly exposed him to a dangerous chemical known to cause cancer while serving in Iraq.

Glen Bootay, 30, joined the Army the day after the Sept. 11, 2001, attacks. A combat engineer assigned to the Third Infantry Division, he was sent to work at a water treatment facility known as Qarmat Ali in April 2003.

According to the lawsuit, while working at the plant, Mr. Bootay was exposed to an orange powder that was "caked" all over equipment at the facility, and that blew over the soldiers as they slept outside.

The powder, the lawsuit said, was sodium dichromate. A chemical used as an anti-corrosive, it contained hexavalent chromium. That, the complaint continued, "is a deadly poison and an amount the size of a grain of sand per cubic meter" is known to cause long-term health problems, including cancer.

Mr. Bootay has been in ongoing treatment for years and suffers from constant headaches and chest pain, collapse of his lungs, extreme fatigue, the inability to sweat, kidney stones, loss of consciousness and short-term memory loss.

At points, the lawsuit said, he would vomit up to 20 times per day and has been required to receive two different types of chemotherapy and take up to 35 medications a day.

"Although he is only 30 years of age, Glen Bootay is required to walk with a cane or walker and is disabled from gainful employment."

A graduate of Washington & Jefferson College before enlisting, the lawsuit said, he has lost his earning capacity.

The lawsuit says KBR knew the chemical existed and allowed it to remain when KBR took over the plant. The lawsuit also includes claims for negligence, fraud and intentional infliction of emotional distress.

It was filed now, the complaint said, because Mr. Bootay only learned of the connection between his illness and KBR from news reports in July.

The company, based in Houston, Texas, said the chemical had been left at the site by Iraqis and was not KBR's responsibility. The company also said the American and British military tested air samples and found no dangerous levels of the chemical.

KBR said when it learned of the chemical at the plant, it asked the Army Corps of Engineers to clean up the site.