UNITED NATIONS (CNN) -- Workers found vials believed to contain the poison gas phosgene at a U.N. office building in New York, U.N. officials said Thursday.

U.N. spokeswoman Marie Okabe said U.N. chemical weapons experts quickly secured the toxic material.

U.N. archivists for UNMOVIC, the U.N. chemical weapons agency, unexpectedly turned up samples of material from an Iraqi chemical weapons plant in old files on Friday, U.N. officials said.

The samples were in weapons inspectors' files dating back to the 1990s, but the substance is not believed to pose any immediate danger, the officials said.

The building where the samples turned up is several blocks away from main U.N. Secretariat building along New York's East River. Tests found no toxic vapors in the offices, U.N. spokeswoman Marie Okabe said. Watch how the chemical scare unfolded »

Phosgene is an industrial chemical used to make plastics and pesticides, according to the Centers for Disease Control and Prevention. At room temperature, it is a poisonous gas, but can be stored and shipped under cooling and pressure.

Phosgene was used extensively during World War I as a choking agent and caused a majority of the war's gas deaths, according to the CDC.

Phosgene gas and liquid are irritants that can damage the skin, eyes, nose, throat and lungs, the CDC said.

The material was taken from al-Muthanna chemical weapons plant north of Baghdad. The samples are sealed and have been there since 1996.

The samples were in containers that ranged in size "from small vials to tubes the length of a pen," Okabe said.

Ewan Buchanan, a spokesman for UNMOVIC, said the substances are in a sealed metal box and wrapped in a plastic bag, "so there is no immediate danger."

Inspectors from UNMOVIC and its predecessor agency UNSCOM were responsible for verifying Iraq's compliance with U.N. resolutions requiring it to abandon its pursuit of chemical, biological and nuclear weapons. The material collected normally would have been destroyed after analysis, UNMOVIC said.

UNMOVIC's mandate ended this year, and its offices are being packed up and moved out, State Department Deputy Spokesman Tom Casey said.

The FBI's Hazardous Materials Response Unit is coordinating with New York police and other agencies to remove and dispose of the material, FBI spokesman Richard Kolko said.

"There is no hazard to the people of New York from this incident," Kolko added.

An FBI team was on its way to the UNMOVIC offices where the samples were found. They will be taken to a U.S. facility in Maryland where previous chemical samples from Iraq's weapons inspections were destroyed, Buchanan said. E-mail to a friend

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