A chemical delivery truck drives up to your facility. The driver gets out and inadvertently connects to a tank containing incompatible material. The chemical reaction leads to a shelter-in-place order for thousands of nearby residents in your community. And at least 140 employees and members of the public need medical attention. Does this make you shudder? Or are you confident you can avoid such a nightmare at your facility?
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The Chemical Safety Board (CSB) recently released its report concerning this very incident that occurred in 2016 at the MGPI Processing Plant in Atchison, Kansas.
Here’s What Happened
MGPI produces distilled spirits and specialty wheat and starches that are used in a wide range of food and beverage products at its facility in Atchison.
On the morning of the incident, a tanker truck from Harcros Chemicals arrived to deliver sulfuric acid. An MGPI facility operator brought the driver to a locked loading dock at a facility tank farm and unlocked the gate to the fill lines, including the sulfuric acid fill line. Unknown to all involved, the sodium hypochlorite fill line was also unlocked. Problems with the two lines included that they:
- Were very close together (only 18 inches apart);
- Looked similar; and
- Were not clearly marked.
We could all write the Hollywood screenplay for what followed.
The operator claims that he pointed out the correct fill line to the driver, but the driver claims he did not. Be that as it may.
The driver connected his truck’s sulfuric acid hose to the sodium hypochlorite line. Over 4,000 gallons (gal) of sulfuric acid entered the tank and mixed with almost 6,000 gal of sodium hypochlorite. The mixture of these incompatible chemicals created a dense cloud that traveled in one direction until the wind shifted the cloud toward a more densely populated area.
Fault All Around
According to the recently released CSB report concerning the incident, there was fault all around, and recommendations were provided for the plant itself, the delivery company, and the Atchison County Department of Emergency Management (ACDEM).
Note: Although ACDEM’s response was largely viewed as a success, several issues and areas for improvement for the department were identified.
The CSB identified several human factors issues that affected how the operator and the driver interacted with the chemical transfer equipment, which ultimately led to the incident. Before the incident, both Harcros’s and MGPI’s procedures required verification that material is being transferred into the appropriate tank and that the tank has sufficient room to receive the chemical. However, both procedures relied on oral communication between the driver and facility operator.
The report points out how applying safer design strategies could have reduced reliance on operator and driver action. According to the CSB, key attributes of equipment, such as accessibility, size, shape, labeling, and color schemes, should be configured by considering human physical and mental capabilities.
OSHA Gets Involved
Following the incident, the Occupational Safety and Health Administration (OSHA) inspected MGPI for compliance with regulations that covered processes and activities involved in the incident, as well as the application of process safety management (PSM) for covered chemicals at MGPI’s tank farm. OSHA also conducted a compliance inspection of Harcros in relation to all applicable requirements while at the MGPI facility.
Subsequently, OSHA issued citations to MGPI and Harcros for violations. Some of the violations issued to MGPI pertained to OSHA’s PSM standard and were covered under OSHA’s National Emphasis Program (NEP) for PSM Covered Chemical Facilities. One of the PSM violations pertained to a process hazard analysis (PHA) requirement for facility siting, specifically regarding occupied structures, including, but not limited to, the control room inside the tank farm building.
Note: Although sulfuric acid and sodium hypochlorite are not covered by PSM, other processes and chemicals at the MGPI tank farm are.
The remaining OSHA violations included:
- Not having adequate emergency exits in the control room;
- Violating requirements for emergency action plans, as MGPI operators were unable to retrieve respirators per the written plan; and
- Not providing employees with the required hazard communication training to follow standard operating procedures to unload sulfuric acid.
Harcros was cited for failing to ensure employees were not exposed to the hazards of chemicals because of the lack of training under OSHA’s hazard communication training requirement. The violation stated that the Harcros driver had not been trained on the appropriate actions to take to prevent cross-contamination of chemicals while unloading, as well as emergency procedures to follow in the event of a chemical release.
How can you avoid such an incident? Check tomorrow’s Advisor for CSB recommendations for the facility, the delivery company, and the local emergency responders.