| Case Name |
Explosion and fire caused due to a runaway reaction on start-up of the preparation of an adhesive manufacturing plant |
| Pictograph |
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| Date |
September 15, 1978 |
| Place |
Hirakata, Osaka, Japan |
| Location |
Chemical factory |
| Overview |
A runaway reaction occurred on starting a batch reactor at an adhesive manufacturing plant, and an explosion and fire occurred. The cause seems to be re-heating, as the temperature did not rise. However, the responsibility of the executive was indicated in the district court because the same kind of accident had occurred before. |
| Incident |
Due to oversupply of steam for heating at a batch reactor of an adhesive manufacturing plant on starting up, a runaway reaction occurred. Combustible vapor, which leaked from the reactor, filled the factory building, followed by an explosion and fire. |
| Processing |
Manufacture |
| Individual Process |
Reaction |
| Chemical Reaction |
Other |
| Substance |
Methylacrylate, Fig2 |
| Acrylic acid, Fig3 |
| Methacrylic acid, Fig4 |
| Methanol, Fig5 |
| Isopropanol, Fig6 |
| Type of Accident |
Explosion, fire |
| Sequence |
A summary of testimony of a worker at the accident site on September 15th, 1978 is as follows.
1. Raw materials such as methyl acrylate and acrylic acid were charged into the reactor.
2. Steam heating and agitation started. The steam valve was closed because the temperature rose to 70 °C.
3. A temperature rising by initiating the reaction did not observed after three to four minutes, instead there was a drop in temperature of about 0.5 °C.
4. A steam valve of a lower jacket was opened a little for reheating. The temperature rose smoothly.
5. Two minutes after reheating began, the temperature rose rapidly to 76 °C. At that time, when the worker looked inside of the reactor, he saw a foam-like material.
6. The steam valve was urgently closed, and cooling water was supplied into the upper and lower parts of the jacket.
7. The liquid seemed to be swelling from the bottom when he looked inside. He judged it to be an unusual reaction, and he informed a person nearby. Gas spouted out from the lower part of the shaft. He heard an abnormal sound in the reactor. He evacuated, and an explosion occurred. |
| Cause |
On starting an adhesive manufacturing plant, a runaway reaction occurred. The temperature did not rise on starting the batch reaction, and the reactor was reheated. The judgment of the operator to reopen the steam valve for reheating seems to have raised the temperature excessively and caused a runaway reaction.
The ignition source might have been an electric spark at a forklift or a water feed pump for a compressor, etc. |
| Response |
Public fire fighters turned out. |
| Countermeasures |
Although the court decision did not specify it, there was a thoughtless error by the worker who reopened the steam valve when the temperature did not rise at the start of the batch. When temperature does not rise, although reheating is often done, it is important to have a well-prepared operation manual and to obey it. |
| Knowledge Comment |
In reactors, it is necessary to prepare an operation manual covering operating conditions, temperature control, etc. Especially in a batch reaction, it is very important to clarify the points requiring care because detailed conditions differ every time. |
| Background |
The cause of a runaway reaction has not been specified. However, the following two points have been indicated according to an Osaka district court decision (final decision). 1) A similar unusual reaction accident occurred previously at the factory, so the accident could have been foreseen. 2) The company had a responsibility to establish safety by investigating the cooling capacity of the condenser. From this fact, it is speculated that management by the company was one of the causes. |
| Sequel |
In court, the fire was considered to have been foreseeable, and the persons related were judged guilty. |
| Reason for Adding to DB |
Example of explosion and fire due to inadequate operation onstart-up of a batch reactor |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Insuficient Education/Training for Safety, Carelessness, Insufficient Understanding, Insufficient Recognition of Risk, Organizational Problems, Poor Management, Slackness of Management, Malicious Act, Rule Violation, Safety Rule Violation, Bad Event, Chemical Phenomenon, Abnormal Reaction, Secondary Damage, External Damage, Leakage/Explosion, Bodily Harm, Death, 3 person died, Bodily Harm, Injury, 33 person injured, Loss to Organization, Economic Loss, Direct Monetary Damage 160 million yen, Damage to Society, Social Systems Failure
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| Sources |
Fire and Disaster Management Agency. Accident examples at manufacturers of dangerous materials. pp.66-67 (1978)
Hajime Kanto, Summaries of 13 judicial precedents for fire-fighters, Modern fire-fighting, October 97, p.85 (1978)
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| Number of Deaths |
2 |
| Number of Injuries |
30 |
| Physical Damage |
Factory: nine buildings collapsed, five buildings partially collapsed, and 188 buildings were damaged (Fire and Disaster Management Agency). Damage to roofs and windows of 120 private houses within a 700 m radius of the factory. (Asahi Shimbun) |
| Financial Cost |
¥ 145 million (Fire and Disaster Management Agency) |
| Consequences |
A blast and a bad smell caused by explosion |
| Multimedia Files |
Fig2.Chemical formula
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Fig3.Chemical formula
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Fig4.Chemical formula
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Fig5.Chemical formula
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Fig6.Chemical formula
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| Field |
Chemicals and Plants
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| Author |
KOSEKI, Hirosi (National Research Institute of Fire and Disaster)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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