The motorway has been closed for hours on the anticlockwise carriageway after a ball of fire engulfed the heavy vehicle travelling near J25 for Waltham Cross.
Road users between J25 and J24 for Potters Bar have been impacted, with emergency services dealing with the scene and assisting with traffic management.
Traffic on the anticlockwise approach is facing diversions, encouraged to exit at J25 to avoid sitting in long delays that are currently estimated between 45 minutes to an hour.
The diversion route advises motorists to take the first roundabout exit onto the A10 southbound, continuing on to the Great Cambridge junction with the A406.
Here, you should follow the westbound carriageway of the A406 to the junction with the A1 where motorists should travel northbound to J23 of the M25.
Once at the roundabout, the first exit will allow you to rejoin the M25 anticlockwise.
According to National Highways, the clockwise carriageway of the M25 has now reopened to traffic.
Drivers should note a 4.7m low bridge on the diversion route, which also takes motorists into the London Low Emissions Zone.
