A roadside service station has been closed on the M1 near Sheffield following a chemical leak.
The fire service said a parked lorry carrying 4,000 litres of nitric acid had leaked some of its load at Woodall Services.
The car park was evacuated at about 0930 GMT. A 50m (164ft) cordon has been put in place around the lorry.
The police and fire service are involved in the incident. It is not known how much acid has leaked.
A specialist team is travelling to the incident to begin the clean-up operation.