West Yorkshire Fire & Rescue Service first received the emergency call at 2.45am on Wednesday, May 19.
The fire is in a furniture factory which adjoins onto a larger mill complex in Legrams Lane.
The affected area of the building is approximately 100 metres by 20 metres, fire crews said.
A total of 18 fire stations are currently at the scene, including crews across from Bradford Leeds, Dewsbury and Wakefield.
Power to the building has been isolated as part of the firefighting operations and power in the local area may also be affected.
Residents in nearby flats have been evacuated.
Other local residents in the Shearbridge area are advised to keep doors and windows closed.
The public is also asked to avoid the area.
A cordon is in place in the area and surrounding roads.
Three primary schools in the area are closed, Bradford Council confirmed.
These are Princeville, Copthorne, Horton Grange and Farnham primary schools.
A West Yorkshire Fire & Rescue spokesperson said: "Firefighters continue to tackle the blaze in Legrams Lane, Bradford.
"The fire is in a furniture factory adjoining a larger mill complex.
"The affected area of the building is approximately 100 metres by 20 metres.
"Power to the building has been isolated as part of the firefighting operations and power in the local area may also be affected. We are working alongside partners from Northern Power to manage this.
"We are also working alongside partners from Police, Ambulance, Bradford Council Emergency Planning team and Yorkshire Water.
"A number of residents from a nearby flats have been evacuated.
"Other local residents in the Shearbridge area are advised to keep doors and windows closed.
"The public is also asked to avoid the area if possible.
"The incident remains 18 pumps in attendance.
"There is a cordon in the area and roads surrounding the building are affected.
"Thank you to the public for your patience as we deal with this incident."
Fire engines at the scene are from the following stations; Bradford, Fairweather Green, Shipley, Odsal, Cleckheaton. Bingley, Stanningley, Keighley, Rawdon, Rastrick, Dewsbury, Hunslet, Killingbeck, Moortown, Garforth.
The Command Unit and support from Featherstone are also at the scene as is the hose laying unit from Mirfield.
Aerial appliances in attendance are from: Halifax, Leeds, Wakefield and Bradford.