Those ramps opened at about 11:45 a.m. today, but the I-880 Market Street off-ramp was still closed at 12:15 p.m.
Lane No. 4 of the I-880 between Market Street and Interstate Highway 980 was also still closed, the CHP said.
It was unclear how far traffic was backed up.
The iodine spill occurred when a drum of liquid fell off the back of a semi truck at about 8:05 a.m., CHP officer Nicole Pacheco said. About 55 gallons were spilled.