MILL VALLEY (CBS SF) — A pool cleaning chemical that created a vapor cloud in Mill Valley Friday morning prompted a shelter in place warning for residents and a nearby elementary school, a Marin County sheriff’s dispatcher said.

The common pool cleaning chemical, muriatic acid, created a vapor cloud in the air at a home at 49 Lomita Drive. As a precaution, the street was closed off at 8:40 a.m. until the substance dissipated, the dispatcher said.

Edna Maguire Elementary School, located at 80 Lomita Drive, was told to shelter in place, the dispatcher said.

The warning was lifted when the cloud dissipated at 9:53 a.m.

No injuries were reported.

The California Highway Patrol and Mill Valley fire and police also responded after someone called the fire department to report the incident at the home.

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