Police are at the scene near the A1(M) where fluid and animal feed has spilled onto the westbound carriageway.
The crash happened around 9.25am today.
A spokesperson from North Yorkshire Police said: "Fluid & animal feed have spilled onto the carriageway - so it will be some time before we can get the road clear. Officers at the scene are working hard to keep traffic moving, but there are long tailbacks, so please avoid the area and seek other routes for your journeys."
Highways England traffic officers who are also on the scene said this is a "complex job" likely to cause "considerable delays".