UNITED NATIONS — Just as its work is wound down toward final shutdown Friday, the unit that for 17 years hunted for Saddam Hussein’s weapons of mass destruction — and in the process became the most watched U.N. operation — survived a new scare yesterday, as one of its inspectors developed a rash, leading to suspicion of contamination by a remnant of a chemical or biological weapon.

The NYPD’s Emergency Service Unit responded to the scene, and the FBI was also contacted, according to a police spokesman, Paul Browne. After tests were conducted on air quality in the building adjacent to the United Nations’ main compound on First Avenue, where the inspector worked, “no traces of harmful substances were found,” a U.N. spokeswoman, Marie Okabe, said. The U.N. Monitoring, Verification, and Inspection Commission staffer first noticed the rash in December, after handling material brought to New York from Iraq. The rash disappeared at the time, and the inspector did not even report the incident to his superiors. Yesterday, however, after wearing the same ski gloves that he had used when he contracted the initial rash, the malady returned, and the inspector asked “out of precaution” to be checked at a U.N. medical facility, according to Ms. Okabe. The incident was then reported to the U.N. security authority.

Officials at the U.N. Department of Safety and Security called the “host country authorities,” Ms. Okabe said. The inspector, whose name was not released, was in fine health yesterday, she added, but his gloves were sent to a laboratory in Edgewater, Md., for further examination.

When Unmovic shuts down its operation Friday, all the material will remain in U.N. possession. It has “already been continuously decontaminated for the last year and a half,” an official who asked not to be named said. Last August, however, a vial that was found at the Unmovic offices led to an evacuation of its building, as it was suspected of containing traces of a chemical weapon. The scare was one of the reasons the Security Council decided to shut down the operation.

Unmovic was established in 2000 to replace older inspection teams that, since the 1991 Gulf War, were charged with verifying that Baghdad destroyed its previously documented arsenal of chemical and biological weapons, as well as all of its long-range missiles. The Vienna-based International Atomic Energy Agency handled Iraq’s nuclear weapons disarmament.

Although the head of Unmovic just prior to the March 2003 invasion, Hans Blix, declared that the inspectors found “no smoking gun,” none of his reports to the Security Council made a conclusive statement saying Saddam’s Iraq had been completely disarmed. Since the war, the inspections team, financed by Iraq, mostly worked on archiving the mountains of material collected during its years of work. Last summer, the Security Council decided to dissolve the team by the end of February.

By yesterday, only three Unmovic workers remained on staff, attempting to complete all the preparations to archive documents, vials, and other materials that had been brought over from Iraq.