(32dc) CSB Process Safety Analysis of the Watson Grinding and Manufacturing Co. Explosion and Fire in Houston, Texas

In the investigation conducted by the Chemical Safety Board (CSB), the cause of the propylene leak was determined to be a disconnected propylene delivery hose, inside a coating booth, due to deterioration and improper fitting to the propylene piping. However, the cause of the propylene accumulation, leading to explosive concentrations, was found to be the improper isolation and safety controls involving the propylene piping and outdoor bulk propylene storage tank which allowed for continuous flow into the coating building. The lack of a process safety management system, process safety culture, and emergency preparedness and response at Watson Grinding also contributed to the severity and consequences of the event on January 24, 2020.

Due to the closing of its business, the CSB did not make recommendations directly to Watson Grinding after its investigation. However, if the business had not closed, an analysis of the findings from the CSB would suggest recommendations including the implementation of a process safety management program, like the Process Safety Management system created by the Center for Chemical Process Safety (CCPS) and adopting an emergency preparedness procedure. Recommendations were directly made to the Compressed Gas Association by the CSB to urge companies within the association, like Matheson Tri-Gas Inc. which supplied propylene for Watson Grinding, to recognize hazards and implement effective process safety management systems. Matheson Tri-Gas Inc. also received a recommendation to urge customers to implement process safety management.

In addition to the recommendations by the CSB, analysis of the disaster was conducted for this report to determine recommendations to be made to OSHA, Associated General Contractors of America, and lawmakers. It was suggested OSHA could require annual or bi-annual audits of previous companies with safety violations to ensure the mandated changes to the system or procedure were upheld. After analysis of this report, there was a suggestion to Associated General Contractors of America to require mandatory reporting of safety infractions by contractors. This suggestion could hold contractors reliable for reporting safety issues observed during repairs or maintenance to OSHA. Finally, lawmakers received a suggestion to revisit the discrepancy between the laws of the Emergency Planning and Community Right to Know Act (EPCRA) and Chemical Facility Anti-Terrorism Standards (CFATS), especially in Texas, as community members were unaware of the hazards at Watson Grinding and Manufacturing Co. in accordance with CFATS. The community in Houston did not feel as if the EPCRA was upheld due to the discrepancies between these two laws, and a revised version of these may have prevented injuries of community members and destruction of the infrastructure.

The explosion and fire at Watson Grinding on January 24, 2020, was a devastating event for Houston, Texas that resulted in fatalities, injuries, and structure damage. The consequences of this event may have been prevented or minimized by the implementation of a process safety management program, commitment to process safety, and emergency response preparedness within the company.