| Case Name |
Explosion and fire of toluene excessively contained in paper in the paper-coating process |
| Pictograph |
|
| Date |
August 10, 1989 |
| Place |
Kasugai, Aichi, Japan |
| Location |
Paper mill |
| Overview |
On August 10th, 1989. An explosion and fire occurred in a paper factory. Paper was coated being with coating liquid, whose main component was toluene, and was dried. The paper dipped into the coating liquid due to a problem with the winding roller. Then combustible gas concentration in the drying furnace increased because the dipped paper entered the drying furnace. A static electricity spark was generated there, and the explosion occurred. Facilities were installed in 1972, and protective devices were not sufficient. |
| Incident |
An accident occurred during usual operation at a coated paper manufacturing plant. The explosion was caused in a hot air drying furnace which dried "coated paper", coated with a coating liquid (containing dangerous material: toluene). A fire followed at coated paper near the electric heater just after the explosion. Half of the factory was destroyed, and part of the machine was also destroyed. |
| Processing |
Consumption and usage |
| Process Flow |
Fig2.Equipment schematic diagram
|
| Substance |
Toluene, Fig3 |
| Type of Accident |
Fire, explosion |
| Sequence |
About 02:35 on August 10th, 1989. The machine was stopped once by a failure of the winder, and was checked. It was confirmed that there was no abnormality, and operation started again. The paper on the usual line was being pulled only by a winder. The failure occurred in the winder again about 30 seconds before the explosion. Therefore, the line speed was gradually lowered from 200 m/minute to 100 m/minute, and to 50 m/minute at the winding control panel.
04:18 An explosion occurred when a worker intended to go to the center control panel to cut the switch of the electric heater. The electric heater was heated to about 250 °C and ignited the coated paper, because the machine stopped due to the explosion.
04:28. The fire was extinguished. |
| Cause |
Due to A failure of a winder, the paper loosened, and workers did not notice that the paper had dipped into the coating liquid (toluene) bath. The paper soaked with toluene ignited and there was an explosion in the high-temperature drying furnace. The equipment was installed in 1972, and protective devices were not sufficient (background to the accident). |
| Countermeasures |
1. Installation of equipment for detecting paper winder failure.
2. Increasing concentration detecting points in the drying furnace.
3. Effective installation of a static electricity eliminating device.
4. Reliable execution of inspections. |
| Knowledge Comment |
Especially in old facilities, installation of protective devices is necessary. |
| Background |
Lack of consciousness of handling a dangerous material such as toluene, which is highly flammable, and lack of safety education were the true causes of the accident. |
| Reason for Adding to DB |
Example of explosion caused due to old-fashioned facilities with insufficient safety equipment |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Inadequate Risk Recognition, Organizational Problems, Inflexible Management Structure, Insufficient Education/Training, Carelessness, Insufficient Precaution, Carelessness of operators, Planning and Design, Poor Planning, Poor Design, Regular Operation, Nonobservance of Procedure, Insufficient Recognition, Bad Event, Mechanical Event, Meander, Bad Event, Chemical Phenomenon, Evaporation/Combustible Gas-air Mixture, Secondary Damage, External Damage, Explosion/Fire, Loss to Organization, Economic Loss, Direct Monetary Damage 200 million yen
|
|
| Sources |
Fire and Disaster Management Agency. Major cases of accidents. Accident that occurred when toluene vapor caught fire when ignited by static electric spark and exploded. Accident cases of dangerous materials. pp.34, 292-293.
|
| Physical Damage |
Destruction of the factory roof. Destruction of drying equipment (a furnace, a duct, a pump, etc.). |
| Financial Cost |
¥ 200 million (Accident cases of dangerous materials) |
| Multimedia Files |
Fig3.Chemical formula
|
| Field |
Chemicals and Plants
|
| Author |
DOBASHI, Ritsu (School of Engineering, The University of Tokyo)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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