YOUNGSTOWN — The explosion and fire at Domestic Uniform Rental, 234 Belmont Ave., Thursday afternoon caused damages of about $150,000 to the building and contents, in addition to the injuries suffered by a worker.

He was taken by ambulance to St. Elizabeth Youngstown Hospital. His condition was not provided. Earlier reports indicated two people were injured, but a Youngstown Fire Department report listed only one. It does not identify him.

The cause of the explosion was listed as unintentional “spontaneous combustion, chemical reaction” involving linen, fabric, fiber, cotton blends, rayon wool.”

The report stated that the explosion had a contributing factor of “mechanical failure, malfunction, other.” It did not deem human factors to be a contributing factor.

Youngstown Fire Battalion Chief Jimmy Drummond said Thursday that one of the extractors “for whatever reason built up a bunch of pressure in the exhaust system.”

When Youngstown firefighters arrived for the 12:12 p.m. incident, they learned that there had been a very large explosion which ignited a fire.

The 30,000-square-foot building is just three blocks way from the central fire station, which is at the corner of Belmont Avenue and Martin Luther King Jr. Boulevard. Domestic Uniform is at the corner of Belmont and Rayen avenues.

Workers were near a man who was injured on the opposite side of the street from the office. All workers had left the building.

When firefighters entered the building, they found rags still in an exploded extractor, and the rags were on fire, the report states.

Firefighters brought a hose to the back of the building and extinguished the flames. The building’s sprinkler system also activated in the area of the extractors.

The company maintenance supervisor said he was not sure what happened, but he shut down both extractors.

Firefighters and maintenance employees removed the rags from the extractors and wheeled them on carts to the shipping docks and wet them down, the report states.

Both extractors were running at the time of the explosion. The one that exploded had been running about 10 minutes, firefighters learned.

Extractors remove chemicals from oily rags before washing them for reuse, the report states.

A supervisor advised fire officials it is possible the refrigeration unit froze up and fumes built up in the extractor and exploded. The door to a front-loading extractor had blown off and was folded, the report states.

The worker who was injured was the only person near the extractor, and he was about 10 feet away rolling carpets at a table. A supervisor said the exhaust duct system had been cleaned about a month ago, and the extractors are cleaned two times per week.

The explosion knocked down drop ceilings in the offices in the front of the building and knocked over desks and shelves in the office. The shop area and offices experienced water damage from the sprinklers, and there were several inches of water on the floor.

Chemicals from the rags inside the extractor were all over from water sprinklers and fire hoses from extinguishing the fire, the report states. Unknown chemicals were on the rags.

Firefighters and their personal protective equipment were exposed to unknown chemicals during extinguishment and cleanup.

erunyan@vindy.com