Health department says Martinez refinery delayed notification of 'coke dust' release by nearly two hours

MARTINEZ, Calif. - A hazardous response team responded on Tuesday to the Martinez Refining Company to investigate the release of "coke dust", according to health officials. 

According to the health department, coke dust is a byproduct of the petroleum refining process. Health officials said there was a nearly two-hour delay from when the refinery first noticed the release of the material at 8:30 a.m. and when they notified the health department through a community warning system at 10:20 a.m.  

The release of the materials lasted one minute, health officials said. 

Contra Costa Health reported that the department's hazardous materials team began collecting samples of the dust for further analysis at a lab.

The coke dust covered the ground, parked cars, and other surfaces in surrounding neighborhoods, the health department said. The material is black and looks like soot. 

Health officials urged the public to refrain from inhaling the material. However, in a statement, they said soap and water can be used to clean the dust from impacted outdoor surfaces. 

"We expect individuals will just wash it off with water. That's what we would advise in terms of this dust and that there should be a limited amount of house impacts," said Dr. Sofe Mekuria Deputy County Health Officer. 

Mekuria further elaborated on the substance, describing it as, "mostly hydrogen and carbon." 

"We are very concerned about the delayed notification to the Community Warning System. We are once again responding to a refinery incident and trying to determine the health impacts," said Contra Costa County Supervisor Federal Glover. "We understand this is an ongoing concern for our community and timely notification is critical."  

This marks the second release of toxic materials at the refinery since Thanksgiving.  

KTVU's Tom Vacar contributed to this report.