Fire Marshal: Chemical explosion unrelated to 2013 death

Bonenfant said this blast was “small”, and that further investigation would determine its cause.

Four of the five workers who were injured in a chemical explosion at a North Andover, Massachusetts, plant on Thursday afternoon, remain hospitalized Friday morning.

The incident happened around 2:30 p.m. on Thursday on Willow Street.

A hazmat tent was being set up at Lawrence General Hospital and two helicopters were waiting to take victims to the hospital. The chemical is highly flammable and reactive, and a fire and explosion hazard, according to the New Jersey Department of Health and Senior Services Hazardous Substance Fact Sheet.

The hospital defines patients in critical condition as having unstable vital signs and possibly having lost consciousness, with unfavorable or questionable indicators.

There is no threat to surrounding residents and businesses, town manager Andrew Maylor told WBZ-TV.

Initially after the explosion at Dow Chemical Company, the workers were able to walk out of the lab with the help of co-workers.

Maylor also confirmed that no chemicals were released into the air due to the blast, and thereby no danger was posed to the nearby area.