A hazardous-materials team and bomb squad responded to a suspicious substance in a Costa Mesa office building Monday morning, but crews quickly determined it was a false alarm, according to Costa Mesa police.

Employees in the mail room at the Auto Club of Southern California building at 3333 Fairview Road found powder in an envelope around 9 a.m. and immediately called authorities, according to the Costa Mesa Police Department.

The FBI, Costa Mesa police and fire departments, Anaheim's hazmat team and an Orange County sheriff's department bomb squad all responded to the call, but on-site testing determined the powder was safe.

There were no evacuations, police said.

A lab will run more tests on the powder, and authorities are still investigating, according to the CMPD.

— Jeremiah Dobruck

Twitter: @jeremiahdobruck