Update: Wednesday, 2:29 p.m.
One lane of the southbound I-5 one mile south of Smokey Bear Road was closed due to an accident involving a tanker truck originally believed to be carrying an unstable substance.
According to CHP Officer John Lutz, the truck was 35 to 40 feet over the side of the road and was hanging on the guard rail.
The SigAlert has been lifted.
The driver, Curt Carpenter, 48, of Newhall, had taken his load of concentrated commercial bleach to Bakersfield, unloaded it and was returning home when he allegedly fell asleep at the wheel.
As the tanker was carrying a hazardous substance and could not be completely purged, officials took great care in making sure the residual bleach did not leak out on to the road. There was a small diesel spill in the area from the truck's fuel tanks. Los Angeles County Fire, Caltrans, and Department of Transportation assisted CHP official at the scene.