The explosion at a chemical plant in East Providence on Wednesday has been ruled an accident by the Rhode Island State Fire Marshal.
Investigators determined the explosion at Aspen Aerogels on Dexter Street “was accidental due to an accumulation of ethanol vapors in a drying oven used in the manufacturing process,” the fire marshal’s office said in a statement Friday.
The oven exploded around 8:15 on Wednesday night. Officials said 13 people were transported to the hospital, though none of them experienced major injuries. All 13 were released from the hospital on Thursday, according to the fire marshal’s office.
City officials also said Friday that the oven that caused the explosion “had open permits that had not been finalized, nor had final inspection,” city spokesman Matt Paddock said in an email.
The city’s building official plans to conduct an investigation, Paddock said.
Aspen Aerogels did not respond to a request for comment.
East Providence Fire Chief Michael Carey said his department and other city officials are also conducting a post-incident evaluation to learn more about damage to the area and the city’s response.
“Thanks to the coordinated work of our firefighters, facility personnel and partner agencies, crews were able to stabilize the building and ensure there was no ongoing danger to the public,” Carey said Thursday. “We will continue working with investigators and facility officials as the post-incident review moves forward.”
Aspen Aerogels develops thermal insulation for use in the energy and electric car industries, according to the company’s website. The company is incorporated in Delaware, but lists its business address as Northborough, Mass., according to documents it files with federal regulators.
This story has been updated with additional information from Matt Paddock.
