The fire started at a factory on Hampton Park Road in Hereford at around 8am.
Some residents in the nearby area have been evacuated to Hereford Leisure Centre on Holmer Road.
More top news
More than 700 foreign crime suspects have been arrested after Birmingham became the centre of a Europe-wide police operation.
Cloud will thicken with some, mainly light, patchy rain possible through this afternoon and into tonight, with some clear spells.
This morning's sunny spells will gradually give way to cloudier, breezier conditions this afternoon, with patchy rain possible later.