CO Poisoning Incident at Plaistow Shaw’s; Four Transported, 300 PPM Reading Reported

October 13, 2025

PLAISTOW, N.H. — At 11:41 p.m., the Plaistow Emergency Communication Center received multiple 911 calls for an odor in the building at Shaw’s, 4 Plaistow Road. Callers reported several people feeling ill.

A box alarm was struck. Within six minutes, Plaistow Engine 1 and Ambulance 1 arrived to find workers evacuating. Crews assisted with evacuation and began triage. Engine crews recorded a carbon monoxide (CO) reading of 300 parts per million near the rear of the store and completed primary and secondary searches.

There were 14 employees present. Four patients were transported to area hospitals with CO-poisoning symptoms. According to the U.S. Department of Labor, 300 PPM is at the high end of a medium exposure level.

The suspected source was a gas-powered pressure washer used indoors by a third-party cleaning company.

Response and notifications: Plaistow Fire (Engine 1, Ambulance 1, Truck 3, C-1, ALS1); Plaistow Police; mutual aid from Atkinson Fire, Kingston Fire, and Newton NH Fire. Notifications were made to the Plaistow Building Official, Plaistow Health Officer, NH Department of Labor, and OSHA.

The store was ventilated and remaining workers were allowed to return to work. Officials note that CO is an odorless, colorless gas and that gas-powered equipment should not be used indoors without proper ventilation and CO monitoring. All patients are expected to recover.