The fire in the Janakkala fireworks storage area likely started from a damaged firework

The Finnish Safety and Chemicals Agency (Tukes) has completed an accident investigation into the explosive fire that took place at Pyrokratia Oy’s fireworks storage area in Janakkala on 5 November 2025. The accident was likely caused by a firework that had been damaged during transport or handling.

Course of events

The accident occurred when an employee was in a storage container inspecting a cardboard box containing professional fireworks that had been returned unused from a fireworks display in France. When the employee touched the firework in the box, it ignited and quickly lit other fireworks in the same container.

The fire spread explosively into several containers in the storage area. Several rescue department units were alerted to the scene. As a precaution, a danger zone with a radius of up to one kilometre was established in the surrounding area, and the residents of the area were evacuated.
 

Probable cause of the accident

The first fireworks lit in the accident were F4 class products intended for professional use only.

The investigation could not prove an individual, certain cause of ignition. The investigation team considers it likely that fireworks returned from the display had been damaged during transport or handling. Damage may have made the product more susceptible to ignition, for example, from spark from static electricity or mechanical friction. 

The investigation also revealed shortcomings in the packing and handling of products returned from displays. The products had been packed together in the same cardboard box without any filler material, allowing them to move during transport.

“The accident demonstrates that the risks may be higher, especially when handling fireworks returned from displays. Clear procedures and responsible persons are needed for the planning of displays and the packing, transport and storage of fireworks used in them,” says Aki Ijäs, Senior Specialist at Tukes.

Information for the investigation was collected from Pyrokratia Oy and the display operator, as well as the police, the occupational safety and health authority, the municipal environmental protection authority and the rescue department. In addition, residents in the vicinity of the accident site were interviewed.

Consequences of the accident

Approximately 3,300–3,550 kilograms of fireworks burned in the fire. The accident site was kept restricted for several days because some of the containers were hot for a long time.

An explosive fire occurred in the warehouse when the employee was carrying out an inventory of professional products and transferring fireworks to containers. The fire spread particularly due to burning fireworks fragments and vehicles parked close to the containers. At the time of the incident, the doors of five containers were open due to the inventory, which made it possible for fireworks fragments to end up in these containers, spreading the fire.

The accident did not cause permanent personal injury.

Tukes issues several recommendations to improve safety

Based on the investigation, Tukes proposes several measures for preventing similar accidents in the sector. The recommendations are available in full in the investigation report.

Display operations

• Clear responsibilities and designated personnel should be defined for the packing and return of products used in fireworks displays, and the dismantling of displays and packing of products must follow pre-agreed procedures.
• The safety practices related to packing and transporting fireworks must be discussed in more detail with the safety adviser.

Handling of returned fireworks

• The condition of products returned from displays or sales, as well as the risks associated with them must be assessed before transporting or storing.
• Non-marketable products must have their own storage location, situated at a safe distance from other fireworks.
• Appropriate filler material should be used in the transport boxes to prevent products from moving inside the package.

Operations of the explosives storage area

• Storage containers must be clearly marked to indicate the type of products stored in them.
• A risk assessment must be carried out on the filling and handling of containers; to minimise the number of containers open at any given time.
• The location of containers and restrictions on vehicle parking in the vicinity of containers must be considered in the planning of the storage areas.

Read the accident investigation report (in Finnish): Explosive fire in fireworks storage area (pdf)

See the slide set (in Finnish): Explosive fire in fireworks storage area in Janakkala on 5 November 2025 (pdf)

Further information for the media: 
Senior Specialist Aki Ijäs (available on 17 March), tel. +358 295 052 682
Senior Officer Sanna Pietikäinen, tel. +358 29 505 268

Emails: [email protected]