Fire marshal identifies cause of Aspen Aerogels explosion in East Providence

EAST PROVIDENCE, R.I. — The Rhode Island State Fire Marshal’s Office has determined that a drying oven caused Wednesday night’s explosion at Aspen Aerogels in East Providence, ruling the incident accidental.

Investigators said the blast happened during the manufacturing process inside the company’s Dexter Road facility, where ethanol vapors built up in a drying oven before igniting. The explosion sent 11 workers to area hospitals, though officials said all were treated and later released.

City officials also revealed that the oven involved in the explosion, identified as Oven 5, had open permits that had not been finalized and had not received a final inspection before being put into operation. East Providence officials said the city’s building official and solicitor will continue reviewing that aspect of the case.

The explosion caused major structural damage to the rear portion of the plant, where steel walls were bent outward and debris was scattered across the facility. Fire officials have said operations at the plant will remain suspended until inspectors confirm the building and fire suppression systems are safe.

In addition to the fire marshal’s investigation, federal OSHA has opened its own review into the explosion, which could take several months to complete. Aspen Aerogels has not yet publicly commented on the findings.