The U.S. Chemical Safety Board (CSB) releases a safety video about the October 21, 2016, toxic chemical release at the MGPI Processing facility in Atchison, Kansas, which reportedly resulted in over 140 reported injuries, and approximately 11,000 citizens forced to evacuate or shelter-in-place. The release occurred during a routine chemical delivery when two incompatible chemicals – sulfuric acid and sodium hypochlorite – were inadvertently mixed, forming the toxic cloud. The video entitled, “Mixed Connection: Toxic Result,” includes a 3D animation of the incident, as well as interviews with a CSB investigator and Chairperson Vanessa Allen Sutherland.
In the video, Chairperson Sutherland says, “Delivery and unloading operations may be perceived as simple compared to other processes at chemical facilities, but because these activities can involve large quantities of chemicals, the consequences of an incident can be severe. Our case study on the MGPI incident stresses that facilities must pay careful attention to the design and operation of chemical transfer equipment to prevent similar events.”
At MGPI a truck from a chemical distribution company, Harcros Chemicals, arrived on the morning of October 21, 2016, to complete a routine delivery of sulfuric acid. An MGPI operator escorted the driver to a loading area where he unlocked the sulfuric acid fill line for the driver to connect the truck’s hose. But the sodium hypochlorite line was also unlocked, and the two lines, which were only 18 inches apart, looked similar and were not clearly marked. The driver inadvertently hooked the sulfuric acid hose to the sodium hypochlorite fill line and the two chemicals mixed, forming a dense cloud containing toxic chlorine gas and other chemicals.
The CSB video notes that chemical distribution takes place on a massive scale in the United States. According to a study by the National Association of Chemical Distributors, more than 39.9 million tons of product were delivered to customers every 8.4 seconds in 2016 – resulting in many opportunities for incidents like the one at MGPI to occur.
The video also features an interview with John Heneghan, the director of the Pipeline and Hazardous Materials Safety Administration’s (or PHMSA’s) Hazardous Materials Safety Southern Region Enforcement Office. Heneghan notes that according to PHMSA’s data from 2014 through 2017, unloading incidents involving hose connections to incorrect tanks occur frequently and are often quite serious because of the large amount of chemicals involved. In fact, since January 1, 2014, eight incidents similar to the MGPI incident have occurred, which caused 44 injuries and evacuation of 846 people.
In the video, investigator Lucy Tyler describes three key lessons learned from the MGPI incident. They are:
- Facilities should evaluate chemical unloading equipment and processes, and implement safeguards to reduce the likelihood of an incident. This should be done while taking into account human factors issues that could impact how facility operators and drivers interact with that equipment.
- Facility management should evaluate their chemical transfer equipment and processes and, where feasible, install alarms and interlocks in the process control system that can shut down the transfer of chemicals in an emergency.
- And facilities should work with chemical distributors to conduct a risk assessment and then develop and agree upon procedures for chemical unloading to ensure responsibilities are clearly defined.
In the video, Chairperson Vanessa Allen Sutherland says, “Chemical deliveries are happening every day all around us. Because these deliveries are so common, the CSB strongly urges the managers of facilities and distributors to review and adopt the key lessons from our case study, and work together to prevent future incidents like the one at MGPI.”
For more information, visit: www.csb.gov