Staff were evacuated from the on-site laundry at Calderdale Royal Hospital in Halifax after a freak blaze.
Firefighters from Halifax, Elland and Huddersfield were called to the hospital at 11.10am today.
Around 25 staff in one of the hospital buildings at the Dudwell Lane side of the site were evacuated.
The main hospital was unaffected and no patients were involved.
Watch commander Adrian Bairstow, of Halifax Fire Station, said two firefighters in breathing apparatus tackled the blaze in an industrial drier.
The contents of the drier – floor mops – had set on fire. There was slight scorch damage to the machine.
Mr Bairstow said a small amount of water was used to put out the flames and the contents of the drier were taken outside and the ground floor laundry ventilated.
Mr Bairstow said it may have been that cleaning chemicals in the mops had not been properly washed out before they went in the drier.
He said staff had been given safety advice and he planned to go back to the hospital to carry out a follow-up inspection.
Fire crews left after about an hour.
