West Midlands Police say one man has been killed and two further injured in a reported explosion at Innovative Environmental Solutions in Oldbury.
The incident happened on the morning of 7 August.
A police spokesperson said: “A man has died following an industrial accident at industrial premises on Union Road.
“Police were called by the fire service at just before 1.50am on Monday morning (7 August).
“Three men were taken to hospital where, sadly, a man in his 50s passed away. Two men in their 30s and 40s remain in a stable condition.
“The case has been passed to the Health and Safety Executive and the Coroner to establish the cause of the incident.”
A West Midlands Ambulance Service spokesman said two victims with serious burns had been taken to Queen Elizabeth Hospital in Birmingham.
Innovative Environmental Solutions is a joint venture between Chinook Sciences – the majority shareholder – and European Metal Recycling.
Its Oldbury End Stage Recycling Plant, a combined recycling and energy-from-waste facility, is designed to process 180,000 tonnes of vehicle shredder residue annually.
Chinook Sciences has been contacted by MRW for comment.