Nashua, NH – Firefighters evacuated 20 Trafalgar Square Thursday after HVAC workers there reported high carbon monoxide readings.

According to a release, readings of up to 200 part per million were found throughout the building, well above levels recommended to avoid health effects with long-term exposure.

High levels were found on the 6th floor by the HVAC workers, who pulled the fire alarm to evacuate the building about 8:13 a.m., the release said.

No injuries were reported. Firefighters were going office to office as they ventilated the building, the release said.

20 Trafalgar Square is located off Exit 8 of the F.E. Everett Turnpike, near the Market Basket supermarket.