Eight fire crews are on the scene of a diesel and ammonia spillage on the A140 at Earl Stonham.
The incident happened at 9.37am this morning.
The fire service was alerted to an oil spillage, but later discovered it was diesel and ammonia which had been spilt from a tanker.
Fire crews from Princes Street, Debenham, Stowmarket, Ixworth and Ipswich East were initially called to attend.
The incident is yet to be deemed as under control by the fire service.