Firefighters responded at about 5:20 p.m. to the report of a structure fire at the business, which is located in an industrial warehouse building at 2311 Skyway Drive, Unit 5, said fire Battalion Chief Alan Widling.
Four engines, a ladder truck and a breathing unit responding to the blaze found moderate smoke coming from both the front glass door and a large commercial roll-up door in the center of the 11-unit industrial complex, Widling said.
He said crews contained the blaze within approximately 25 minutes after forcing entry through the front door with a hose line and discovering that fire enveloped floor to the ceiling in the workshop area.
Ventilation holes were made in the roof, at which time fire crews saw the blaze had spread into the second level.
Widling said occupants told investigators that the last employees left the building about 20 minutes before the fire was reported.
Investigators determined the cause of the fire was unintentional and originated in a pile of solvent soaked rags left in the workshop area, he said.
Minor smoke and water damage were reported in the two adjacent businesses, and preliminary damage is estimated at $100,000 to the structure and $50,000 to contents, Widling said.
No injuries were reported, although American Medical Response provided a standby ambulance.
Santa Barbara County and San Luis Obispo County fire departments each provided an engine to cover several additional emergency responses that occurred in the city while Santa Maria fire units were committed to the structure fire.