No Detection: Explosion at Watson Grinding

Summary

On January 24, 2020, a deadly explosion occurred at Watson Grinding and Manufacturing Company in Houston, Texas, when propylene gas leaked and ignited. The incident, which claimed three lives and caused significant damage to nearby structures, was the result of safety failures, including an ineffective gas detection system, poor equipment choices, and inadequate emergency response. The Chemical Safety Board (CSB) found that Watson Grinding lacked a proper Process Safety Management system and emergency preparedness, which could have prevented the tragedy. The CSB urges companies to adopt comprehensive safety management systems and training to prevent similar incidents.

Takeaways

• 😀 The Watson Grinding and Manufacturing Company explosion occurred on January 24, 2020, in Houston, Texas, caused by an accidental release of propylene that ignited and resulted in fatalities and widespread damage.
• 😀 The explosion led to the death of two workers and one nearby resident, with hundreds of neighboring structures, including homes and businesses, sustaining major damage.
• 😀 Watson Grinding lacked an effective system for addressing potential hazards, including the absence of a mechanical integrity program and written operating procedures for the propylene process.
• 😀 Employees at Watson Grinding did not receive adequate emergency response training, contributing to the severity of the incident.
• 😀 The company failed to isolate the propylene storage tank after the workday, leaving it open overnight and allowing gas to leak into the coating building.
• 😀 A gas detection system was installed in the coating booths but was disconnected from the control system years before the explosion, making it ineffective in detecting and responding to the gas leak.
• 😀 Despite concerns raised by contractors and internal discussions, no action was taken to fix the malfunctioning gas detection system before the explosion.
• 😀 Watson Grinding used an improper rubber hose instead of a more robust copper tube, which degraded over time, leading to a propylene leak that contributed to the incident.
• 😀 The company did not conduct a hazard analysis to identify the risks associated with the propylene process and failed to implement necessary safety measures to prevent a leak.
• 😀 The lack of an effective emergency response plan and insufficient worker training on handling hazardous chemical releases worsened the outcome of the incident.

Q & A

What caused the massive explosion at Watson Grinding and Manufacturing Company?

The explosion was caused by the accidental release of propylene, which accumulated inside a building and ignited.

What were the main safety issues identified in the investigation of the Watson Grinding explosion?

The two main safety issues identified were process safety management and emergency preparedness.

What was the consequence of Watson Grinding not having an effective system to address potential hazards?

The lack of an effective hazard management system contributed to the release of propylene and the subsequent explosion, resulting in three fatalities and significant property damage.

How did Watson Grinding fail in maintaining safety systems at the facility?

Watson Grinding failed to maintain an operational automated gas detection system and did not implement required mechanical integrity or operating procedures to control the hazards associated with propylene.

What critical safety system failed to function, leading to the explosion?

The automated gas detection system, which was supposed to detect leaks and shut off the flow of gas, was disconnected from its computer control system and rendered ineffective.

How did Watson Grinding fail to address the risks associated with the use of propylene?

Watson Grinding did not conduct a proper hazard analysis, did not replace deteriorating equipment (like the rubber hose), and did not implement a process safety management system, leaving the facility vulnerable to the dangers of propylene.

What was the role of the gas detectors in the coating booths?

The gas detectors were meant to detect dangerous levels of flammable gas and trigger alarms, start the exhaust fan, and close shut-off valves to prevent a dangerous situation.

Why were the gas detectors disconnected from the control system?

The gas detectors were disconnected due to a lack of follow-through after warnings from contractors, and despite being discussed in meetings, no action was taken to restore the system.

How did the workers respond upon suspecting a propylene leak?

Two employees smelled propylene and reported the suspected leak, but they were not advised to evacuate. One of them continued to investigate the leak, which led to the ignition and explosion.

What was the emergency response plan at Watson Grinding, and how did it fail?

Watson Grinding had an emergency response plan that identified propylene as a fire hazard, but it did not address how to respond to a leak or suspected leak. The workers were not trained to recognize or properly respond to a gas leak, which led to their failure to evacuate and contact emergency responders.