Investigation update into 2023 chemical explosion released

23 July 2024

The US Chemical Safety and Hazard Investigation Board (CSB) has released an update into a toxic chemical release that occurred on 23 January 2023, at the Honeywell Performance Materials and Technologies facility in Geismar, Louisiana. The incident seriously injured a worker and is the third serious incident at the facility in the last three years.

Image: Honeywell

A reboiler at the facility catastrophically exploded, leading to the release of over 870 pounds (394kg) of hydrogen fluoride (HF) gas and nearly 1,700 pounds (771kg) of chlorine gas, both highly toxic substances. Local officials closed nearby highways, and workers at the facility sheltered in place. Honeywell estimates the property damage to be approximately $4 million (£3m).

The CSB’s update states that the most recent mechanical integrity inspections of the reboiler prior to the explosion were in September 2020 (in which Honeywell used ultrasonic thickness testing) and in October 2021 (in which Honeywell conducted an internal visual inspection of the reboiler).

Based on the September 2020 inspection, Honeywell had estimated 1.1 years of remaining service life for the reboiler shell. After the October 2021 visual inspection, Honeywell personnel recommended that the shell be replaced at the next shutdown opportunity, and in January 2022, Honeywell initiated a project to purchase a replacement reboiler shell. Management approved the project but did not purchase or install a replacement shell before the reboiler ruptured on 23 January 2023.

A Boiling Liquid Expanding Vapor Explosion (BLEVE) occurred due to the conditions inside the reboiler at the time of failure. This resulted in the sudden release of the HF, chlorine gas, and other substances from the reboiler, distillation column, and other ancillary equipment.
The CSB is continuing to gather facts and analyse several key areas, including:

- Honeywell’s mechanical integrity policies and practices
- Honeywell's project management policies and practices
- Relevant facility, corporate, and industry standards

To read the investigation update in full, click here.