UPDATE: Contra Costa County Health Services sent a hazardous materials team to monitor flaring at the Chevron refinery in Richmond tonight, but found “no levels of concern” in the air.

“Flares are a safety device used in refineries to relieve pressure during the refining processes and keep our equipment and plants operating safely,” Chevron Richmond said in a statement via Twitter.

RICHMOND (BCN) — Contra Costa County Health Services is monitoring flaring reported at the Chevron refinery in Richmond Tuesday night.

County health officials announced via Twitter at 8:36 p.m. that a hazardous materials team was responding to the area and monitoring air quality.

Chevron Richmond confirmed via Twitter that visible flaring had occurred, but called it “an important part of keeping the refinery running safely.”

Further details were not immediately available.