No Way Down: Chemical Release at Wacker Polysilicon

Summary

This video highlights a preventable tragedy at Voder Polysilicon's Charleston, Tennessee facility, where a hydrogen chloride release resulted in one fatality and multiple injuries. The incident was caused by a series of safety oversights, including inadequate written procedures, poor control of hazardous energy, and lack of safety protocols for simultaneous operations. Additionally, the facility's design lacked proper means of egress, preventing safe evacuation. The Chemical Safety Board (CSB) outlines several critical safety recommendations to prevent similar incidents, urging companies to adopt stricter safety practices, better hazard assessments, and updated industry standards.

Takeaways

• 😀 A fatal industrial accident occurred at Voder Polysilicon in Charleston, Tennessee, when hydrogen chloride gas was accidentally released during maintenance on November 13, 2020.
• 😀 The incident resulted in one worker fatality and several others sustaining serious injuries due to inadequate safety procedures and poor hazard management.
• 😀 Workers were exposed to hydrogen chloride gas, which can cause serious injuries such as chemical burns or death, due to improperly torqued bolts on the heat exchanger piping.
• 😀 The lack of written procedures for maintenance tasks led to miscommunication and errors, as workers were relying on verbal instructions rather than clear, written guidelines.
• 😀 The company failed to implement adequate control measures for hazardous energy during the maintenance work, leaving the workers exposed to risks from the pressurized chemical system.
• 😀 The simultaneous work being carried out by multiple contractor teams on the same platform created safety risks, as workers were exposed to the hazardous gas release without proper hazard assessments.
• 😀 Inadequate personal protective equipment (PPE) was worn by some workers, particularly those from the Penol team, who lacked chemical-resistant suits during the hazardous work.
• 😀 The building design did not account for emergency situations, with only one available exit route, which was blocked by the toxic gas, making it impossible for workers to escape quickly.
• 😀 The CSB identified the lack of a formalized SimOps (Simultaneous Operations) program as a critical safety gap, with no coordinated hazard assessments or procedures to manage the interaction between concurrent tasks.
• 😀 Recommendations from the CSB include the development of detailed written maintenance procedures, stricter control of hazardous energy protocols, a formalized SimOps program, and improvements to egress requirements to address safety gaps in industrial settings.

Q & A

What caused the incident at the Voder Polysilicon facility on November 13, 2020?

The incident was caused by an inadvertent overtightening of bolts on a heat exchanger's vapor outlet piping. This resulted in the heat exchanger cracking, releasing hazardous hydrogen chloride gas into the atmosphere.

What were the immediate consequences of the hydrogen chloride release?

The release led to one fatality, two serious injuries from falls while attempting to escape, and chemical burns to workers exposed to hydrogen chloride gas. The hazardous cloud blocked access to the only staircase, which made evacuation difficult.

What safety issues did the CSB identify as contributing to the incident?

The CSB identified four key safety issues: lack of written procedures, inadequate control of hazardous energy, lack of hazard assessment for simultaneous operations (SimOps), and insufficient means of egress in the facility.

Why was there no written procedure for tightening the bolts on the heat exchanger?

Voder Polysilicon relied on verbal instructions and the manufacturer's equipment manual, which lacked detailed torque specifications for each type of connection. This led to confusion and improper bolt tightening.

How did the lack of control over hazardous energy contribute to the incident?

Voder did not apply hazardous energy control procedures to the torquing operation, even though the heat exchanger contained pressurized hydrogen chloride gas. Without these precautions, workers were exposed to dangerous conditions when the equipment was inadvertently damaged.

What was the issue with simultaneous operations (SimOps) at the site?

Multiple contractors from different companies were working in the same area without proper coordination. The Penol workers, who were not wearing chemical protective PPE, were exposed to hydrogen chloride when the gas was released, while they were performing insulation work at the same time as more hazardous tasks.

Why was the facility’s single staircase inadequate during the emergency?

The design of the facility included only one staircase for evacuation, which became blocked by the hazardous hydrogen chloride cloud. Despite prior employee concerns, no additional exit routes were added, preventing a safe evacuation.

What specific action did the CSB recommend to prevent a similar incident in the future?

The CSB recommended several actions, including developing detailed maintenance procedures, applying energy control procedures to all hazardous equipment, creating a formal SimOps program, and implementing additional means of egress in elevated work areas.

What is the significance of energy isolation in safety procedures?

Energy isolation ensures that all hazardous energy sources are properly managed during maintenance activities, minimizing the risk of accidental releases or exposure. In this incident, the failure to apply these procedures left workers exposed to dangerous chemicals.

What does the CSB say about industry standards related to SimOps?

The CSB noted that existing industry standards regarding SimOps are mostly limited to offshore environments and are not comprehensive for stationary chemical processes. The lack of clear regulations for SimOps in chemical plants contributed to the incident and is a safety gap that needs to be addressed.