U.S. Chemical Safety Board Opens Investigation Into Fatal Chemical Tank Implosion at Nippon Dynawave Paper Mill in Washington

Washington, D.C., May 27, 2026 - The U.S. Chemical Safety and Hazard Investigation Board (CSB) announced today that it is opening an investigation into the fatal chemical tank implosion at the Nippon Dynawave Packaging paper mill facility in Longview, Washington, that occurred during the early morning hours of May 26.

A team of CSB investigators will be arriving at the incident site in Longview today.

According to local authorities, the incident involved the rupture and implosion of a large tank containing white liquor, a corrosive chemical solution used in paper and pulp processing.

Initial reports to the CSB indicate that the incident resulted in multiple fatalities and serious injuries. Several workers are unaccounted for as emergency response and recovery operations continue.

CSB Chairperson Steve Owens said, "The CSB is opening an investigation into this tragic incident to determine how it happened and what can be done to prevent something like this from happening again."

The CSB will provide additional information as it becomes available. Updates on the investigation will be posted at the agency's website

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The CSB is an independent, nonregulatory 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 to identify root cause of releases; 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 Director of External Affairs Hillary Cohen at [email protected]