U.S. Chemical Safety Board Releases New Safety Video on the Fatal 2020 Explosion at the Optima Belle Facility in Belle, West Virginia
Washington D.C., May 22, 2025 - Today, the U.S. Chemical Safety and Hazard Investigation Board (CSB) released a new safety video on its investigation into the fatal December 8, 2020, explosion at the Optima Belle chemical facility in Belle, West Virginia.
The CSB's new safety video, called “Outsourcing Responsibility: Explosion at Optima Belle,” includes an animation of the events leading to the incident, and commentary from CSB Board Member Sylvia Johnson, Investigator-In-Charge Vonzella Vincent, and Investigator Drew Sahli.
Optima Belle is a toll manufacturer – a company that provides chemical processing services under contract to other companies, typically using its own equipment. On the day of the incident, Optima Belle was working on behalf of Clearon Corporation (Clearon). As part of its agreement with Clearon, Optima Belle was to dehydrate a chemical product called CDB-56, a reactive compound, in batches using a piece of equipment called a rotary double cone dryer. Because Clearon had never before used this type of pressurized dryer to dehydrate CBD-56 and Optima Belle had never before dehydrated CSB-56, Optima Belle, in conjunction with Clearon, developed a new procedure to use the rotary double cone dryer for the dehydration operation.
The CSB’s investigation found that Clearon did not give Optima Belle sufficient information about CDB-56’s chemical properties to use when developing the new procedure for the rotary double cone dryer. In addition, neither Clearon nor Optima Belle performed an extensive thermal hazard assessment or located adequate publicly available information on the chemical hazards of the compound. Consequently, Optima Belle did not realize that heating CDB-56 inside the dryer could cause the compound to unexpectedly decompose at temperatures below the dryer’s maximum internal temperature of approximately 130 degrees Celsius. The decomposition reaction produced gas that sharply increased the pressure inside the dryer to above the dryer’s design limit.
At approximately 10:00 pm on December 8, 2020, the dryer exploded, and toxic chlorine gas released to the atmosphere. Metal debris and dryer fragments propelled off-site and within the facility, striking a methanol pipe that then caught fire, leading to an estimated $33.1 million in property damage. One Optima Belle employee was fatally injured, two others were evaluated for respiratory irritation, and one member of the public reported an injury related to the explosion. The explosion prompted local authorities to issue a shelter-in-place order for the region within two miles of the Optima Belle site for over four hours. Debris from the explosion was found almost a half mile from the site.
The CSB released its final report on its investigation in July 2023. The new safety video covers the five key safety issues identified in the CSB’s report that contributed to the incident: process knowledge management, thermal hazard assessment, equipment selection and design, tolling of hazardous materials, and regulatory coverage of reactive hazards. The video also highlights safety recommendations made by the CSB in the report to Optima Belle, Clearon, the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA).
Among other important issues, the CSB’s report and the new video point out that although CDB-56 is a reactive chemical that can undergo a self-accelerating decomposition when heated, it and many other such reactive chemicals are not regulated under OSHA’s Process Safety Management (PSM) standard or the EPA’s Risk Management Program (RMP) rule. Consequently, the CSB recommended that OSHA amend the PSM standard to achieve more comprehensive control of reactive hazards that could have catastrophic consequences and that EPA amend the RMP rule to explicitly cover catastrophic reactive hazards that have the potential to seriously impact the public.
In the video, Board Member Johnson states, “Our report identifies several factors that led to this tragedy. In particular, we have found that gaps in the existing regulations do not adequately protect against hazards presented by reactive chemicals. This longstanding safety gap must be addressed."
Board Member Johnson added: “The CSB believes OSHA and the EPA must strengthen their regulations on reactive chemicals. Regulations addressing reactive hazards will help keep similar incidents from occurring, prevent injuries, deaths, and protect those who live in nearby communities. The time is now for those agencies to act.”
The CSB is an independent federal agency charged with investigating incidents and hazards that result, or may result, in the catastrophic release of extremely hazardous substances. The agency’s core mission activities include conducting incident investigations; formulating preventive or mitigative recommendations based on investigation findings and advocating for their implementation; issuing reports containing the findings, conclusions, and recommendations arising from incident investigations; and conducting studies on chemical hazards.
The agency's board members are appointed by the president subject to Senate confirmation. The Board does not issue citations or fines but makes safety recommendations to companies, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA.
Please visit our website, www.csb.gov. For more information, contact Communications Manager Hillary Cohen at [email protected].