Before chemical spill, WA reviewed different Nippon tank that could explode

At the time of the May 26 fatal tank collapse at Nippon Dynawave Packaging, state labor safety investigators already had two cases pending involving other parts of the Longview industrial plant. A common thread with those two investigations was malfunctioning valves.

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According to Washington State Department of Labor & Industries documents obtained through a public records request, one investigation stemmed from an April incident in which a worker backed into a sinkhole and was briefly covered with hot stock while trying to close a spraying drain valve that had been stuck open.

The other still-open investigation stemmed from a March complaint about a malfunctioning valve on a clarifier tank containing aqueous ammonia solution.

Ammonia tank involved in earlier Nippon Dynawave investigation

This photo obtained in a records request shows a tank involved in a Washington State Department of Labor & Industries investigation opened in March complaining that this ammonia tank at Nippon Dynawave Packaging in Longview had a broken valve creating a "risk of toxic exposure or pressure buildup and explosion." The investigation is still ongoing, but the agency states that when inspectors found that the company has since taken the tank offline and repaired it.

"This is creating a hazard because delivery drivers are inhaling toxic air; also, if the pressure is not released, it will build up, and too much pressure will make the tank explode," the complaint states.

The ammonia tank investigation is still pending, but according to an L&I release issued earlier this month, the company has since "taken the tank offline and repaired it."

The case file documents were part of a trove of Washington State Department of Labor & Industries records shedding light on nine other closed workplace safety investigations that the state agency has conducted on Nippon Dynawave Packaging since the Japanese company purchased the Longview plant from Weyerhauser in 2016. It listed the two pending investigations, plus case information on nine completed investigations.

Of those completed investigations, four resulted in L&I issuing violations, and three were classified as "serious," resulting in fines. Six were handled with in-person inspections.

Ammonia tank outside state review

The case file illustrates the nuance involved in health and safety investigations. According to documents in the case file, Nippon argued that the ammonia solution involved was not classified as a "Highly Hazardous Chemical" under Washington Administrative Code Chapter 296-67 and thus was not subject to state law requirements.

The exact concentration of ammonia in the tank is redacted in the public record as a trade secret, but Nippon explained in the response that the solution falls well below the state's minimum threshold of 44% ammonia.

"That said, we do maintain process and equipment information for safe operation of the system under our applicable safety and environmental programs," the company said in a response in the case file. Another company document states that there had been no incident reports related to the storage tank in the past two years.

A safety data sheet lists the substance as having category III toxicity, which is considered slightly irritating to the respiratory tract.

1 valve malfunctioning for year

The most recently opened L&I investigation - at least prior to the May 26 tank collapse - was an incident the company classified as a "near miss" that occurred about 7 p.m. April 9, in which a worker fell into a sinkhole filled with scalding hot paper stock caused by a broken drain valve on a paper machine tank.

According to incident reports in the case file, the mid-stock valve hadn't been closing properly for more than a year. The report describes an "Energy Control Procedure" that caused the valve to break free and spray hot product onto the ground, carving a 3-foot-by-3-foot hole in asphalt and gravel.

Sinkhole at Nippon Dynawave

This photo obtained in a Washington State Department of Labor & Industries records request shows the sinkhole - covered by a metal plate - that was involved in an April 9 "near miss" incident at Nippon Dynawave in which fell into the roughly 3-foot by 3-foot hole and was briefly submerged in scalding hot paper stock. The incident is still under investigation.

The worker tried to close the upset valve by positioning himself on top of a pipe, but fell back, not seeing the hole. His chest was submerged for approximately 30 seconds.

He was quickly hosed down and was protected somewhat by a rain suit. The incident was not classified as an injury, but rather a "near miss."

WA fines issued for 3 of 9 complaints

Some investigations closed without any violations appear to be due to legal limitations. For instance, the earliest safety and health compliance investigation was opened in late 2017 regarding the use of an overhead crane to slow a 38-ton reel of paper. The machine, actually designed to slow the paper reel, was not working properly.

L&I's report described "possible dynamic loading concerns" with a remotely operated crane maneuvering full paper reels down a set of rails. The report noted "a lack of exposure to any employees," but L&I investigators closely scrutinized operations manuals, safe work practices, Washington Administrative Codes, and standards set by the American Society for Mechanical Engineers before concluding that "the department is unable to find any verbiage which prohibits this procedure."

In late 2018, the agency closed an inspection after a worker was injured when a machine started unexpectedly, causing a roll of paper to drop and break the worker's leg. Few details about this incident were provided in the L&I documents, but the agency stated that investigators found no violations on inspection.

The plant's first "serious" violation was issued in February 2020, and resulted in a $700 fine. It stemmed from an investigation opened in the fall of 2019 regarding the company not properly "locking out" the controls when sending two workers to clean equipment.

Second press roll area involved in L&I investigation

Nippon Dynawave workers complained to the Washington State Department of Labor & Industries that they were directed to enter this area to clean a press, but the machine was not properly "locked out" to prevent the possibility of it turning on unintentionally. L&I ultimately fined the company $700 in February 2020.

The case file notes that L&I received a second similar complaint while that investigation was pending, but investigators were unable to follow up. During the investigation, a safety manager told L&I that the press had a redundant safety system in its design, but L&I ultimately determined that it did not meet lockout standards.

The highest fine it received was $2,700 issued in June 2021 regarding face coverings during the COVID era.

Another $700 fine was issued in 2021, when an investigator, in the middle of an unrelated inspection, spotted a contract worker about 5 feet off the ground without fall protection.

The most recent violation was issued last year, when a worker on April 21, 2025, lost most of their right ring finger while replacing a spool on a conveyor belt and making adjustments. L&I's violation, however, was for failing to hold the scene of an accident, as required by state law after any workplace incident involving an amputation or loss of an eye.

The safety manager reportedly explained to L&I that equipment was probably moved "so it wasn't laying around out there." L&I ultimately issued one "general" violation for moving the equipment before inspection. No fine was imposed.

Complaints without WA inspections

Several other complaints were closed without inspections.

In May 2020, the agency received complaints that unqualified managers were operating equipment after the qualified operator went home sick.

A worker who complained to the state agency told L&I that the machine had not been in operation for nearly two decades. Nippon's response was that the issue was actually a union dispute, and stated that the managers in question had extensive previous experience and were responsible for certifying employees to work with the machinery.

The following month, another complaint came in about bolts in the ground causing trip hazards, along with gaping floor holes and narrow walkways.

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Nippon explained that work was being done in the area at the time, where a hole needed to be opened up. The company provided L&I photos of temporary guard rails and floor hole coverings installed to protect workers while the problem area was under repair.

In each of those two investigations, plus a third opened in January 2021 regarding a separate incident in which COVID precautions were not enforced, L&I determined that "no further action was required."

In a release that included information about the complaints it had received, L&I explained that in cases where it was "not an urgent safety and health concern," the agency begins the investigation through correspondence with the company.

"The employer is still required to investigate and address any issues as part of this process," the response states, adding that the agency also follows up with the employee involved. "If the employer's response is not adequate, LYI conducts an inspection."

Safety reviews outside L&I

Beyond those L&I incidents, past safety meeting minutes show a log of safety incidents of varying severity over the past year that were not L&I investigations.

They include an Oct. 18, 2025, incident where a worker needed first aid after drops of white liquor fell on his neck while investigating a causticizer with a transmitter issue. The worker was wearing personal protective equipment at the time, the area was taped off immediately after the incident and "all safety requirements had been met," the report states.

'The buck stops with the employer': Behind oversight limitations at Nippon

Every petroleum tank beneath a gas station is inspected every three years, but no state agency was required to inspect the roughly million-gallon tank at Nippon Dynawave before it collapsed.

On Nov. 21, a worker fell back on his tailbone while installing a chain on the hog fuel dump truck, and the chain he was pulling fell.

Another incident included a fire involving scaffolding boards that occurred at 10:25 a.m. Dec. 8, 2025, on the fourth floor of a boiler. After the employee extinguished the fire, the worker notified their supervisor and the debris was removed.

On Jan. 7, 2026, the report describes a "near miss" incident involving a leaking steam hose in the basement near a water treatment plant. The worker had been using a straight thread adapter when a pressure-tight fitting was required. The valve was ultimately closed until a proper fitting could be installed.

And on Jan. 11, a security guard reported a chemical exposure outside the clarifier tanks. The worker reported smelling a "strong rotten egg smell," then immediately experienced shortness of breath, burning in their eyes and throat, a headache and a runny nose. A medic on site evaluated the guard, and the worker was taken to the emergency room.

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