Search

Fatal Metal Treatment Facility Explosion: CSB Final Report

Posted on 6/12/2025 by Lion Technology Inc.

The US Chemical Safety and Hazard Investigation Board (CSB) issued its final report following an investigation of an incident that occurred May 30, 2024, at a metal treatment facility in Tennessee.

Three employees suffered minor burns. A fourth employee suffered major chemical and thermal burns on 95% of his body and died later the same day.
The incident also resulted in multiple fires, over $1 million in property damage, and the…facility being shut down for approximately 8 months.

Fatal Metal Treatment Facility Explosion: CSB Final Report

What Caused the Chattanooga Explosion?

On the day of the incident, five rollers were placed in 800ºF salt baths used in the nitriding process. Each roller was a large cylinder that had an empty cavity with drain holes on the top and bottom.

When the rollers were lifted out of the salt bath, the salt did not fully drain from one of the rollers and created a solid plug at the roller’s bottom.

The rollers were resubmerged to remove residual salt, but the salt plug prevented water from properly draining out of the plugged roller. The water in the roller quickly heated up, released steam, and caused the salt bath to erupt.

US CSB Made Three Recommendations

Implement Physical Barriers

Implement physical, protective barriers around the molten salt baths that isolate employees from hazardous releases at all locations that perform liquid nitriding.

Develop a Safety Management System

Develop a safety management system that incorporates industry guidance and includes, but is not limited to:
  • A hazard analysis program for assessing the nitriding process.
  • Written operating procedures for the nitriding process.
  • A training program, including written materials, for the employees involved in the nitriding process.
  • An incident investigation program.

Hire a Process Safety Manager

For each facility, establish a position with specific professional expertise and experience in safety management systems, such as risk-based process safety.

Find a Post

Compliance Archives

Lion - Quotes

Lion provided an excellent introduction to environmental regulations, making the transition to a new career as an EHS specialist less daunting of a task. Drinking from a fire hose when the flow of water is lessened, is much more enjoyable!

Stephanie Weathers

SHE Specialist

The instructor does a great job at presenting material in an approachable way. I have been able to save my company about $30,000 in the last year with what I have learned from Lion!

Curtis Ahonen

EHS&S Manager

The instructor had knowledge of regulations and understanding of real-world situations. The presentation style was engaging and fostered a positive atmosphere for information sharing.

Linda Arlen

Safety & Environmental Compliance Officer

Lion's training was by far the best online RCRA training I've ever taken. It was challenging and the layout was great!

Paul Harbison

Hazardous Waste Professional

I love that the instructor emphasized the thought process behind the regs.

Rebecca Saxena

Corporate Product Stewardship Specialist

Lion's information is very thorough and accurate. Presenter was very good.

Melissa Little

Regulatory Manager

We have a very busy work schedule and using Lion enables us to take the course at our own time. It makes it easy for me to schedule my employees' training.

Timothy Mertes

Hazmat Shipping Professional

Well designed and thorough program. Excellent summary of requirements with references. Inclusion of regulations in hard copy form, as well as full electronic with state pertinent regulations included is a great bonus!

Oscar Fisher

EHS Manager

Lion does a great job summarizing and communicating complicated EH&S-related regulations.

Michele Irmen

Sr. Environmental Engineer

I think LION does an excellent job of any training they do. Materials provided are very useful to my day-to-day work activities.

Pamela Embody

EHS Specialist

Download Our Latest Whitepaper

This guide will help you identify 25 of the most -cited errors in RCRA training, recordkeeping, hazardous waste ID, container management, universal waste, and laboratories.

Latest Whitepaper

By submitting your phone number, you agree to receive recurring marketing and training text messages. Consent to receive text messages is not required for any purchases. Text STOP at any time to cancel. Message and data rates may apply. View our Terms & Conditions and Privacy Policy.