EXETER, N.H. (AP) – Authorities said 17 workers complaining of nausea and lightheadedness were taken to the hospital after a chemical used in asbestos removal caused a reaction at the post office in Exeter, N.H.

The U.S. Postal Service office on Front Street was evacuated about 10 a.m. Thursday.

Assistant Fire Chief Ken Berkenbush said it was determined that the 17 suffered from carbon monoxide poisoning, and at least some have already been released from the hospital.

WBZ-TV’s New Hampshire Bureau Chief Lauren Leamancyzk reports:

Crews were removing asbestos from the building Wednesday night, and a chemical was used that gassed off into carbon monoxide during the morning on Thursday.

Fire officials measured carbon monoxide at 50 parts per million, which is not enough to make anyone instantly sick. Prolonged exposure to those levels, however, can cause problems. So, customers were fine but employees eventually were sickened.

There were no serious injuries, and all workers are expected to be released Thursday.

The building is closed until further notice.

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