CSB calls for improved heater safeguards at chemical facilities

After concluding its investigation of a California chemical facility fire, the Chemical Safety and Hazard Investigation Board (CSB) is calling for improved heater safeguards to prevent similar incidents and ensure worker safety.

The November 2023 fire was caused by an overheated refinery furnace. As the furnace malfunctioned, a worker was sent to turn off part of the machinery. However, a metal tube in a fired heater ruptured, resulting in dangerously high temperatures and the release of renewable diesel and hydrogen that ignited the fire.

CSB recommends these safeguards at chemical facilities:

• Establish requirements “for when troubleshooting in close proximity to fired heaters should be stopped and other actions.”
• Configure process equipment with safe operating limit/not-to-exceed limit alarms that alert workers when equipment has reached an unsafe condition.
• Ensure fired heaters are adequately protected from operating with low flow.
• Implement “walk the line” practices such as verifying valve positions before starting up a unit, understanding operating procedures and equipment routings, and properly communicating and documenting shift turnover information.