Cheshire Police are continuing to work with Cheshire Fire & Rescue Service, Cheshire West and Chester Council, Public Health England and North West Ambulance Services at the scene of a major incident on the M56 in Cheshire.
The incident involves a HGV tanker which overturned on the eastbound carriageway between junctions 12 and 14 at approximately 3.45pm today, Tuesday 19 October.
It has now been confirmed that the tanker was carrying a hazardous, but non-explosive, substance, a significant quantity of which has leaked out onto the carriageway.
As a result of the incident the M56 remains closed in both directions between junctions 11, Daresbury, and 14, Hapsford.
The cordon in place around the scene of the incident has now been reduced to 400m, with residents in the Plover Lane area of Helsby advised to stay indoors with their windows and doors closed at this time.
Motorist who are within view of the tanker are advised to turn off their air conditioning ventilation system and close their windows.
Highways England will be patrolling the tailbacks to help anyone who is in need of assistance.
The train line through Helsby has now reopened, although delays are expected on services between Runcorn, Chester and Liverpool.
The closures are expected to remain in place for several hours.
Motorists are advised to avoid the area.
There are believed to have been a small number of casualties, they are all being treated by North West Ambulance Service.