By CBSLA Staff

IRWINDALE (CBSLA) – Suspicious envelopes containing a white power forced the evacuation of a building belonging to Southern California Edison in Irwindale Thursday morning and prompted a hazmat callout. However, the substance was later deemed harmless.

Oct. 29, 2020. (CBSLA)

The suspicious envelopes were reported before 8:40 a.m. at a SoCal Edison mail processing center in the 6000 block of Irwindale Avenue, according to the Los Angeles County Fire Department.

READ MORE: Venice High School Unable To Use Its New Multimillion Dollar Stadium Due To A Dispute With A Neighbor

Employees, who had just completed training regarding suspicious materials, were sifting through incoming mail when they came upon the envelopes, Irwindale police said.

All employees in the building were evacuated and hazardous materials teams from both the L.A. County Fire and L.A. County Sheriff’s departments were brought in to investigate.

READ MORE: Family Members And Loved Ones Gather To Remember 10-Year-Old Anthony Avalos Who Would Have Been 13 This Week

Hazmat teams tested the substance and determined it to be “benign” with “no public health risk,” LACFD reported. Investigators also determined the envelopes were not criminal in nature.

The employees were all wearing protective masks and gloves when they handled the envelopes. Firefighters examined the employees and did not believe they were exposed to anything harmful.

“They were asymptomatic, they were not injured…so we’re still evaluating to see if it is even a threat, what the substance is, if it’s something dangerous,” Irwindale police Sgt. Rudy Gatto said.

MORE NEWS: 2 People Were Critically Injured After A Balcony Collapse In Malibu Saturday; 4 Other People Were Also Transported To The Hospital

It is still unclear exactly what the substance was.