Storage Tank Ruptures and Catches Fire at Stora Enso's Imatra Industrial Site

A storage tank ruptured and caught fire at Stora Enso's Kaukopää industrial site in Imatra, southeastern Finland, early on August 18, spilling about 50 cubic metres of tall oil onto the site, with some of the substance entering nearby Lake Saimaa.

The incident occurred at about 2 a.m. when the plant's control room detected what appeared to be an explosion and alerted emergency services. Toni Jaako, a duty fire officer with the South Karelia Rescue Department, said the tank had ruptured in an explosion-like event.

The fire was brought under control after more than two hours of firefighting. No injuries were reported, and no other tanks were damaged. About 15 rescue service units responded to the incident.

Some of the spilled tall oil reached Lake Saimaa through a stormwater drain. Booms were placed around the affected area, while Stora Enso staff began removing the substance from the water using a suction tanker.

Janne Kallio, director of Stora Enso's Imatra mills, said the situation in the lake was under control and the company expected to complete the removal operation during Tuesday morning.

Tall oil is a by-product of the pulp-making process and is used to produce process chemicals for the pulp industry. Jaako described it as a sticky, bitumen-like substance that moves slowly through pipelines and is biodegradable.

The cause of the rupture remains under investigation. Jaako said Stora Enso was examining why pressure had increased inside the tank and caused it to rupture.

Production at the Imatra mills was temporarily shut down to allow damage assessments and repair work to begin. The duration of the shutdown was not immediately clear.