Thirty people have been treated and 11 taken to hospital after a chemical spill at a Little River service station this afternoon.
Emergency services were called to the BP service station on the Geelong-bound side of the Princes Freeway about 12.45pm after a hazardous liquid started spilling out from a tank on the back of a truck.
A CFA spokeswoman said about 30 to 50 litres of the chemical had spilled from the truck.
CFA and Ambulance Victoria spokespeople said they were unable to identify the chemical at this stage.
Susannah Hicks from Ambulance Victoria said ambos had assessed 30 people at the scene.
Ms Hicks said 11 people have already been taken to Geelong Hospital in a stable condition, and the remaining 19 will also be taken to hospital for further observation.
It is not known what has caused the spill.
A CFA spokeswoman said CFA members in protective gear were busy isolating the leak and cleaning it up.
An exclusion zone has been established and the CFA warned that the vapour was very odorous and maybe smelt as far away as Lara, Little River and Coccoroc.
One lane is closed in each direction on the Princes Freeway, and police are directing traffic.
