A fire at a Northern California petroleum storage facility was called a “hazardous materials emergency” after it started spewing a massive black smoke cloud and heavy orange flames on Tuesday afternoon, KTVU reports. The fire reportedly started at around 2:15 p.m. at NuStar Energy, which stores oil along with other liquids and refined products. Contra Costa County fire officials said three tanks containing ethanol were on fire, and firefighters were using foam and water to extinguish the blaze. No injuries have been reported. Contra Costa County Sheriff advised area residents to close their windows, doors, and turn off any fans due to the potentially toxic materials in the air. NuStar said there were only “two impacted tanks” in the fire that were “holding very low volumes of ethanol.” “All personnel are safe and accounted for,” the company said in a statement. The cause of the fire has yet to be determined.