An industrial unit had to be cordoned off during Friday morning following a fire.
Lancashire Fire and Rescue Service sent four crews to Brierley Street, near Aqueduct Street.
The incident saw the water safety system set off after a fire involving a commercial oven at Ribble Technology sand blasting and paint strippers premises.
A 15 metre cordon was put in place due to a large amount of steam coming from the premises and carbon monoxide being detected in the building.
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Fire crews from Preston, Fulwood, Penwortham and Bamber Bridge attended.
The fire service left the scene shortly after 1pm on Friday (2 February) and passed the incident to the Health and Safety Executive and the Preston City Council environmental health department who are working with the site’s owners on the cause of the fire and the carbon monoxide levels.
Staff were sent home from the premises, which are near the West Coast main line, following the fire.