More than 175 firefighters tackled a major blaze at the East Yorkshire factory of wood preservatives and treatments manufacturer Bartoline Ltd on Friday.
Up to 31 fire engines from Humberside Fire Brigade were sent to the Beverley factory, where a fire broke out at about 9.30am followed by an explosion. Staff were evacuated from the site and no casualties were reported.
Station officer Tony Harvey said a warehouse, six associated buildings and a number of large container tanks were reported on fire, with woodcare products believed to be affected.
The Swinemoor Industrial Estate was sealed off and local residents advised to stay inside and keep doors and windows shut. Witnesses reported seeing black smoke from up to 20 miles away.
Bartoline, established in 1876, manufactures light and dark coal tar creosote; the Woodtone water-based timber treatment designed for dipping or spraying fencing panels and sheds; canned shed and fence treatments; linseed oils and teak oil.
The company, which also produces manufacturing and packing solvents, distributes its products extensively through wholesale, retail and trade outlets across the UK.