Pool chemicals spilled onto northbound State Route 125 near Grossmont College Drive Wednesday, prompting a response from a hazardous materials team.
The spill was the result of a crash involving a pool supply truck at about 7:15 a.m., the California Highway Patrol (CHP) said.
A Sig Alert was issued and part of the northbound SR-125 north of Grossmont College Drive was shut down as the hazmat team tended to the spill, CHP said. One lane was left open for commuters.
The Navajo Road on-ramp to SR-125 was also closed.
Crews said it would take about two hours to clean up the spill.