UPDATE 10:50am: CFA firefighters are transferring a chemical from what was a leaking tanker to a second truck.
CFA District 2 Operations Officer Andy Waterson said enough of the chemical had been transferred to the second truck and as a result, it is no longer leaking.
The incident was called under control at 10.30am.
Earlier: CFA crews are mopping up a small chemical spill on the Calder Freeway at Gisborne.
Firefighters were called to a truck leaking a small amount of hydrochloric acid just before 6am.
CFA District 2 Operations Officer Andy Waterson said crews on scene were dealing with the incident and would decant the truck as soon as possible by pumping the chemical into another tanker.
An Advice message has been issued.
Police are on scene for traffic control and north-bound lanes of the Calder Freeway are currently closed.
The incident is not yet under control.
Around 11 CFA vehicles are attending from Gisborne, Sunbury, Mt Macedon, Riddells Creek and Macedon.
Author: CFA Media