The CSB says 19 Chevron employees were engulfed in a white vapor cloud that formed when a hydrocarbon process fluid escaped from a ruptured pipe. The cloud was so dense that workers could not see and some had to feel their way out on hands and knees.
A Chevron firefighter was able to escape from a truck only because he was wearing full fire protection gear.
The CSB makes 17 urgent recommendations to Chevron, including using pipe made from materials less likely to corrode. It also makes recommendations to Contra Costa County, urging stronger regulations that would trigger pipe replacement when corrosion is found.
"It gets to a general philosophy within the refining industry that, we believe, should be improved and that is the active adoption of safer technologies instead of waiting for things to break or to be detected through inspection," said U.S. CSB Managing Director Daniel Horowitz.
A public meeting will be held on Friday night at the Richmond Convention Center.