Three people have been injured after a chemical incident at a bio-fuel plant just outside Peterborough.
The incident occurred at the Pure Fuels plant in Stibbington.
Police, fire and ambulance crews all attended, as did an air ambulance.
This is the second time the emergency services have attended the plant in recent months. An explosion in November left two people injured.
Police said the Health and Safety Executive is now investigating the latest incident.
A spokeswoman for the force said: “We were called by the fire service at about 6pm yesterday evening (Wednesday) with reports of a chemical spillage at Pure Fuels Ltd in Old Great North Road, Stibbington.
“All three emergency services attended. There are believed to be three casualties. The extent of the injuries is not known. The investigation has been passed to the Health and Safety Executive.”
An East of England Ambulance Service spokesman said: “Four ambulances attended reports of a spillage of sulphuric acid next to Nene Valley Railway, Wansford Station, Old Great North Road, Stibbington, around 6.20 yesterday evening.
“We treated a patient at the scene for burns and transported them to Peterborough City Hospital.”
A Cambridgeshire Fire and Rescue Service spokesman said: “At 5.40pm on Wednesday crews were called to an incident at an industrial premises on Old Great North Road near Stibbington.
“Crews from Stanground, Dogsthorpe, Yaxley, St Neots and the north roaming fire engine attended the scene.
“Firefighters arrived to find an incident involving a small amount of chemical. They worked with paramedics to provide emergency first aid to a male casualty, who was taken to hospital by ambulance.
“They made the area safe and returned to their stations by 7.30pm.”
The process for bio-fuel production currently used at the plant turns used cooking oils into other fuels which can be used to power lorries and cars as well as generate electricity.
The Peterborough Telegraph has this morning contacted Pure Fuels and the Health and Safety Executive.