Washington — Establishing and implementing engineering controls as “preventive safeguards” throughout a course of hazard evaluation will help stop liquid overflow and a attainable chemical catastrophe, the Chemical Safety Board says.

The company makes that conclusion in a latest remaining report on a deadly chemical release and hearth in September 2022 on the BP-Husky Energy Refinery in Oregon, OH.

CSB investigators discovered {that a} deadly release of the flammable liquid naphtha resulted after two staff opened a pressurized vessel for emergency draining functions. The vessel normally contained solely vapor; nonetheless, “a series of cascading – and worsening – events throughout the day” contributed to the catastrophe, a CSB press release states.

This included greater than 3,700 alarms sounding within the 12 hours earlier than the incident, delaying responses and upsetting facility processes. The report means that the employees might have believed the vessel contained an amine-water resolution – not naphtha.

CSB asserts that preventive safeguards comparable to a high-level interlock to shut the naphtha feed valve to the absorber stripper tower “would have automatically stopped the identified liquid overflow events.” Instead, the power relied on alarms “that require human intervention, emergency pressure-relief valves and downstream safety instrumented systems.”

Other classes for the business:

• Ensure – by means of coaching, clearly written procedures and different means – workers are clearly empowered to train stop-work authority and perceive they’re anticipated to take action.
• Process hazard analyses ought to consider overfill hazards and contemplate situations wherein a vessel might not overfill to the highest however might as an alternative overflow or backflow by means of different piping connections.
• Realize that irregular conditions introduce stress and should set off poor selections from operators. Think by means of conditions earlier than they happen and have plans in place. Define working limits past which irregular scenario administration procedures ought to be adopted and clearly outline these corrective actions to be adopted to cease a sequence of irregular occasions.
• Ensure alarms are properly justified.
• Create programs to make sure learnings from inner and exterior incidents are included all through the group to stop recurring failures.

“Nearly everything that could go wrong did go wrong during this incident,” CSB Chair Steve Owens stated within the release. “The tragic loss of life resulting from this fire underscores the importance of putting in place the tools that employees need to perform tasks safely, such as stop-work authority, and having adequate policies, procedures and safeguards in place to effectively manage highly stressful abnormal situations, including alarm floods.”