A massive chemical tank ruptured at a paper mill in Longview, Washington, on Tuesday morning, killing at least one person, injuring nine others, and leaving nine workers unaccounted for as emergency crews worked through the day to stabilise the site. The incident occurred at approximately 7:15am local time at the Nippon Dynawave Packaging facility, a paper and pulp plant located in Longview, a city in Cowlitz County roughly 45 miles north of Portland, Oregon, and 130 miles south of Seattle.

The tank contained "white liquor", a highly corrosive alkaline solution of sodium hydroxide and sodium sulfide used in the production of paper pulp. While early estimates suggested the tank held around 80,000 gallons of the chemical, officials later revised that figure dramatically upward to approximately 900,000 gallons — with an estimated 90,000 gallons still remaining inside the damaged structure. The injuries reported include chemical burns and inhalation injuries ranging from minor to critically severe, affecting eight employees and one firefighter, who was later treated and released. PeaceHealth St. John Medical Center in Longview confirmed it had received multiple patients, with six in fair condition and others transferred to additional facilities.

Recovery operations remained suspended Tuesday evening because the tank was still structurally unstable, creating hazardous conditions for emergency personnel. Battalion Chief Matt Amos of the Longview Fire Department said recovery efforts would resume on Wednesday once the site could be made safer. Authorities consistently stressed that the incident posed no direct threat to the surrounding community, and no evacuation order was issued. Washington Governor Bob Ferguson expressed condolences and confirmed that state ecology workers had been deployed to assist local officials.

Nippon Dynawave Packaging is a wholly-owned subsidiary of Nippon Paper Industries, Japan's second-largest paper manufacturer by sales, which acquired the Longview plant from Seattle-based timber company Weyerhaeuser for $225 million in 2016. The facility, which employs around 1,000 people and produces tissues, printer paper, cups, plates, and cartons, has previously experienced incidents on site, including a major fire involving wood piles in July 2023.

The disaster in Washington comes amid a separate but unrelated chemical scare in southern California, where an overheating industrial tank containing methyl methacrylate — a highly flammable plastic-making chemical — prompted a precautionary evacuation affecting around 50,000 residents near Garden Grove in Orange County. Officials said on Monday that the worst-case risk of explosion had passed after a crack relieved pressure in the tank, and crews were working to allow evacuees to return home.