The U.S. Chemical Safety and Hazard Investigation Board (CSB) released a pair of videos on chemical accident investigations that concluded last fall.
The safety videos explored the causes of an explosion and a fire at the AB Specialty Silicones in Waukegan, Illinois, which killed four workers, destroyed the facility’s production building, and caused extensive damage to nearby businesses, as well as a fatal fire in a confined space at the Evergreen Packaging paper mill in Canton, North Carolina, when a heat gun fell into a bucket of flammable resin, killing two contract workers in a connected vessel.
The video on the explosion and fire at AB Specialty includes computer animation of the events that led to the incident and interviews with both the CSB’s chairperson and the lead investigator. Two incompatible chemicals stored in nearly identical containers were mixed at the facility during the production of an emulsion product. The chemicals reacted and produced flammable hydrogen gas that ignited, causing the fatal explosion.
The CSB concluded that the facility lacked a flammable gas detection and alarm system to warn employees of a hazardous atmosphere and that AB Specialty had a “weak process safety culture.”
The board has investigated many accidents resulting from inadequate recognition and evaluation of reactive chemical hazards. The CSB called for stricter environmental and occupational safety regulations to help prevent reactive chemical accidents in its report released on September 24, 2021, reiterating earlier recommendations for the EPA to revise its risk management plan (RMP) regulations and for the Occupational Safety and Health Administration (OSHA) to revise its process safety management (PSM) of highly hazardous chemicals standard.
“It is past time for regulators to fully recognize the hazards presented by reactive chemicals,” Chairperson Katherine A. Lemos said in the video. “We call on OSHA and EPA to update their regulatory standards to include better coverage of reactive chemicals.”
OSHA has a rulemaking intended to modernize the PSM standard to help prevent major chemical accidents.
Evergreen Packaging fire
The video examining the fatal fire at Evergreen Packaging includes computer animation of the events leading up to the incident and interviews with the CSB chairperson and the supervisory investigator for the incident.
In its report, the CSB identified four safety issues contributing to the incident at Evergreen Packaging: hot work safety, prejob planning, confined space safety, and combustible materials of vessel construction. Workers failed to recognize an electric heat gun as an ignition source requiring a hot work permit, and Evergreen and its two contract firms treated connected vessels as separate confined spaces.
The CSB reiterated a recommendation for OSHA to publish a Safety and Health Information Bulletin (SHIB) addressing the hazards and controls when using flammable materials in confined spaces. The agency has not yet issued an SHIB on the use of flammable materials in confined spaces. The CSB issued a new recommendation that OSHA put out guidance, such as a letter of interpretation (SIL), addressing the analysis and control of hazards that are not preexisting but result from work activities inside permit-required confined spaces. OSHA has not yet issued new employer guidance regarding hazards arising from work activities in confined spaces.