AirGas Facility Fatal Explosion

On Sunday, August 28, 2016, at approximately 12:10 pm, a nitrous oxide trailer truck exploded at the Airgas manufacturing facility in Cantonment, Florida. The explosion killed the only Airgas employee present and heavily damaged the facility, halting nitrous oxide manufacturing at Cantonment indefinitely.

The U.S. Chemical Safety and Hazard Investigation Board (CSB) determined the most probable immediate cause of the incident was that during initial loading of a trailer truck, a pump heated nitrous oxide above its safe operating limits. Exceeding these critical safety limits appears to have started a nitrous oxide decomposition reaction that propagated from the pump into the trailer truck, causing the explosion. The CSB has documented its causal determination throughout this report based on a review of the evolution of corporate activities related to nitrous oxide production at the Cantonment site and other relevant facilities, a history of nitrous oxide decomposition explosions in the industry, and an analysis of all available physical, documentary, and testimonial evidence.

A definitive determination of the event that started the explosive decomposition of nitrous oxide is not possible due to the force of the explosion, the extent of damage to the facility, the minimal available process data, the absence of surviving eyewitnesses, and the lack of safety controls needed to prevent other potential sources of nitrous oxide decomposition. This report examines other theoretical causes of the explosion, including possible contamination of the nitrous oxide and the lack of an electrical bonding and grounding system needed to prevent static electricity, both of which could contribute to or cause nitrous oxide explosions.

Federal regulations require many types of chemical facilities that manufacture highly hazardous substances to have process safety management systems in place to protect their workforce and the public. The majority of these specialized rules do not apply to nitrous oxide facilities; specifically, neither the Occupational Safety and Health Administration’s Process Safety Management standards, nor the Environmental Protection Agency’s Risk Management Plan rule apply to the Airgas Cantonment facility. This is true despite the fact that since 1973, the nitrous oxide industry has averaged one major explosion about every seven years. These incidents killed six workers and injured 21 other people. In addition, since 2001 these explosions have occurred more frequently with an average of one explosion every four years during that timeframe.

The CSB investigation found that Airgas lacked a safety management system to identify, evaluate, and control nitrous oxide process safety hazards, which led to the explosion. Although not required by Federal regulations, good practice guidance recommends developing and implementing a robust safety management system to manage the hazards relating to manufacturing, transferring, and shipping nitrous oxide. The contributing causes of the explosion that killed the Airgas employee all stemmed from the company’s lack of an effective overall process safety management system.