Nippon Dynawave Packaging has been fined US$77,800 by the Washington State Department of Labor & Industries (L&I) following an investigation into a March 2026 workplace incident at its pulp and paper mill in Longview, Washington, in which an employee nearly became engulfed in hot pulp after falling into a sinkhole.

March incident reveals recurring pulp spills and safety failures

According to L&I, the incident began when a drain valve on a tank was unintentionally left open, allowing hot pulp to spill onto the ground. The pulp, at approximately 145°F (63°C), accumulated to a depth of around three feet, concealing a four-foot-deep sinkhole that had formed in the asphalt below.

The employee entered the spill area to stop the flow. He waded through the thick pulp and climbed onto piping to reach and close the valve. When he attempted to return to the ground, he fell into the concealed sinkhole.

The worker managed to grab a pipe and eventually caught his foot on the side of the sinkhole, allowing him to climb out. Without the pipe, he would have been completely engulfed in more than seven feet of hot pulp.

L&I found that approximately 3,400 gallons of pulp per minute are pumped from the tanks into the paper machine building. In this case, the material continued flowing onto the ground for approximately two hours. The temperature of the pulp leaving the tanks can range from 125°F to 160°F (52°C to 71°C).

The investigation also revealed that pulp spills occurred at the mill approximately once every couple of months, and sometimes more frequently. Paper machine managers were aware that employees had previously waded through spilled pulp to open and close tank valves.

L&I cited Nippon Dynawave for failing to protect employees from exposure to extremely hot material and the risk of engulfment. The company was also cited for failing to include its paper machine pulp system in a required hazardous-material piping safety program.

The total penalty amounts to US$77,800, comprising US$74,910 for a willful serious violation involving employee exposure to thermal and engulfment hazards and US$2,890 for the piping safety program violation.

Following the incident, management agreed to instruct employees not to enter pulp spill areas and to develop procedures and engineering controls allowing valves to be closed without exposing workers to the hazards.

Nippon Dynawave has 15 days from the date the citations were issued to appeal.

L&I emphasized that this investigation is separate from the May 26, 2026, catastrophic white liquor tank failure at the same facility, which killed 11 workers and injured nine others. The investigation into that fatal incident remains ongoing.

Separate May tank failure killed 11 workers

On May 26, 2026, a 1.2-million-gallon atmospheric storage tank, known as G Tank, catastrophically failed, releasing approximately 900,000 gallons of white liquor, a highly caustic chemical used in pulp production.

The liquid, at approximately 200°F (93°C), flooded the surrounding courtyard and nearby buildings where employees were gathered for morning meetings. Eleven workers were killed and nine others were injured. Three sustained serious injuries, while five additional employees and one firefighter were injured but did not require inpatient hospitalization.

CSB found tank had been deemed unfit for service before failure

The U.S. Chemical Safety and Hazard Investigation Board (CSB), which is investigating the disaster, reported in August that an external inspection conducted in July 2025 had identified significant thinning of the tank's carbon-steel shell, with sections below the minimum safe thickness required for continued operation.

The inspection contractor recommended further internal inspections and repairs, stating that the tank was not fit for continued service unless the identified areas were repaired and warning of a high likelihood and consequence of failure.

Additional external inspections in October 2025 and February 2026 also found that substantial portions of the tank shell remained below the minimum safe thickness. However, the tank was neither internally inspected nor repaired, taken out of service, or operated under reduced conditions before its eventual failure.

On the day of the accident, a process upset required the mill to stop transferring white liquor from G Tank to the digestor, where it is used to produce pulp from wood chips. However, white liquor continued entering the tank from the mill's recausticizing process, causing its level to rise to approximately 90% capacity by 6:22 a.m.

At approximately 7:09 a.m., G Tank catastrophically failed, releasing approximately 900,000 gallons of scalding hot, highly corrosive white liquor.

The CSB's investigation is examining the causes and contributing factors, including the company's mechanical integrity, inspection and maintenance practices, operating conditions preceding the failure, and emergency response procedures.