Video: Key Lessons from $600M "Popcorn Polymer" Explosion in Texas

Late last year, the US Chemical Safety and Hazard Investigation Board (CSB) issued an investigation report focused on a chemical facility explosion that injured two employees and caused a combined $603 million in damages to the facility and the surrounding homes and businesses. 

In their report and the newly released video, CSB identified the cause of the explosion as a buildup of "popcorn polymer" in an unidentified dead leg—an unused/inactive line of pipe—in the facility’s butadiene process. The polymer built up for more than 100 days before rupturing the pipe. Within minutes of the pipe failure, 6,000 gallons of flammable butadiene leaked, vaporized, ignited, and exploded.

US CSB released a video that details the four key safety issues that it believes led to the incident. Read about those issues here, see our takeaway, then watch CSB's video for more details.

In this article:

• CSB Video: The Danger of Popcorn Polymer
• Four Key Safety Issues
• Our Takeaway

CSB Video: The Danger of Popcorn Polymer

Four Key Safety Issues

Dead Leg Identification and Control

The facility’s operating procedures did not include identification of potential dead legs.

After replacing a pump that was out of service with a backup, popcorn polymer built up in a dead leg for at least 114 days before rupturing.

A Chemical Safety Board official noted that, if the facility had identified the dead leg, personnel could have taken one of three actions to control popcorn polymer buildup:

• Prioritizing repair of the pump that was replaced.
• Purging the piping.
• Adding popcorn polymer inhibitor to the dead leg.

Process Hazard Analysis Action Item Implementation

A Process Hazard Analysis (PHA) performed in 2016 noted the hazard of popcorn polymer accumulation causing low-or-no flow was identified. The PHA team recommended the facility flushed lines monthly when equipment is out of service for maintenance.

CSB found that the recommendation was not implemented.

Control and Prevention of Popcorn Polymer

In 2016, the facility introduced operational trials for its butadiene unit and reduced the amount of popcorn polymer inhibitor that was injected into the production stream.

The facility then experienced increased popcorn polymer formation within the process, and employees noticed as early as May 2016.

Employees continued to experience buildup and equipment plugging in the butadiene process.

Due to plugging in the process, employees considered shutting down the butadiene process for a mini-outage to clean up the popcorn polymer and bring the unit up to best practice standards.

Remotely Operated Emergency Isolation Valves

The final issue is, once the incident began, it became too dangerous to use the local, manual emergency shutoff valves installed at the facility. Remotely Operated Emergency Isolation Valves may have allowed employees to shut down other parts of the facility from a safe location, shortening the incident.

Takeaway: OSHA PSM and HazCom Compliance 

This incident underscores the critical importance of compliance with OSHA’s Process Safety Management (PSM) Standard, and the Hazard Communication Standard (HCS) for training and informing employees about hazardous chemicals at work. 

The PSM Standard exists to prevent or minimize the consequences of catastrophic releases of hazardous chemicals. Employees working at covered facilities must be trained “in an overview of the process and in the operating procedures” that emphasizes safety and health standards, emergency operations (including emergency shut down), and safe work practices [1910.119(g)(1)(i)].

Three employees noticed a cloud of gas forming from a ruptured pipe, they wasted no time removing themselves from the area. Without adequate training and information about hazardous chemicals on site, employees may be unsure about the hazards of a substance leaking from a pipe during an emergency. They may react with too little urgency, or might panic unnecessarily. In this case, the employees' split-second decision to evacuate almost certainly saved their lives.  

Tags: CSB, popcorn polymer, safety video