Case Ditails

Scenario
Case Name Explosion and fire of light oil evaporated at a waste oil regeneration factory
Pictograph
Date August 30, 1975
Place Toyo, Ehime, Japan
Location Waste oil regeneration factory
Overview At a factory where regeneration of waste oil from the tanker was executed, an explosion occurred at the end of the work day. There was a lot more combustible gas generated in the indoor vessels than during a usual day. However, the employees seemed not to take precautions against the presence of gas. The gas exploded due to a fire source, and caused serious damage. The facilities and the mode of operation were selected without taking into account the dangerous nature of the material handled, and the real cause of the accident lay with manager and proprietor.
Incident At a factory that regenerated waste oil from a tanker, usual operation was performed and stopping procedure was underway. An explosion occurred on stopping. Waste oil, which was a mixture of oil and water from a tanker, was transferred to an indoor open tank via a water-oil separator. Then, regenerated oil flowed into a recovery oil tank after warming and cleaning as usual. After finishing the operation, the power switch was turned off. Then an explosion and fire occurred. A 1000 kL outdoor recovery oil tank and a 1500 kL outdoor recovery oil tank also exploded and caught fire.
Although gas generated at the water-oil separator was discharged from a vent stack of 30 m high, there is no record of the facilities that discharge the combustible gas generated at a heating drum, etc. in the building.
Processing Manufacture
Individual Process Waste oil recovery
Process Flow Fig2.Unit process flow
Substance Waste oil
Type of Accident Explosion, fire
Sequence Operation proceeded usually through the day. When the electric switch was turned off at the end of work, an explosion occurred.
Cause The content of light components was high in the waste oil that was treated on the day. It was heated to 70 °C in an open heating drum as usual. Therefore, in the heating drum or a downstream process, a large volume of combustible gas was generated, and it filled the inside of the factory building. As the work was done in daytime only, an explosion and fire occurred due to an electric spark on turning off the power supply switch at the end of the work. Although a large volume of combustible gas was generated, the employees did not seem to take any measures. The details are unknown because the persons working at the site died. Poor management of a combustible gas and use of non-explosion-proof type electric devices were direct causes.
Response Fire extinguishing by the public fire brigade and the private fire brigade.
Countermeasures 1. The factory staff should grasp the properties of received waste oil, and determine the processing method that matches the oil properties.
2. The heating drum and tanks downstream should be changed to a closed type, and safe discharge facilities for the generated gas should be installed.
3. Electric devices should be changed to an explosion-proof type.
In short, the following were established: Safe facilities and safe handling methods suitable for the properties of waste oil handled.
Knowledge Comment As waste oil is a mixture of various materials, it is very dangerous. The employees worked without considering these dangers. It is important to educate employees.
Background In an open heating drum and a recovery oil tank, light gas easily evaporates outside the vessel. The quantity of light gas discharged is also large if the light component of the receiving waste oil is large. Increase in the concentration of gas is natural because the vessels were indoors. The employees did not take precautions. Managers and superintendents, who left the facilities and operation as it was, are responsible for the accident..
Incidental Discussion It was a major accident which also involved passers-by. Currently, there are an increasing number of accidents with industrial waste including waste oil disposal.
These accidents seem to occur due to the double structure of industrial in Japan, This accident is typical of those occurring in a small company, which should be more careful when handling dangerous materials. What can we do?
Reason for Adding to DB Example of fire caused due to operation neglecting the hazards of light hydrocarbons in waste oil
Scenario
Primary Scenario Poor Value Perception, Poor Safety Awareness, Inadequate Risk Recognition, Organizational Problems, Poor Management, Poor Work Management, Ignorance, Insufficient Knowledge, Insuficient Study and Experience, Planning and Design, Poor Planning, Poor Design, Malicious Act, Rule Violation, Safety Rule Violation, Secondary Damage, External Damage, Explosion/Fire, Bodily Harm, Death, 8 person died, Bodily Harm, Injury, 5 person injured, Loss to Organization, Economic Loss, Direct Monetary Damage 50 million yen
Sources Fire and Disaster Management Agency. Examples of accidents at dangerous materials manufacturers. pp.356-357 (1975)
Ministry of Labor, Outline of explosion hazard at NM waste oil treating company (1975)
The Ministry of Labor Safety section, Case of explosions and fires, and countermeasures. [A] Explosion gas, vapor, etc. Examples of labor accidents and countermeasures. New edition pp.214-215 (1984)
Kawasaki City Association of dangerous materials for safety research Explosion and fire at waste oil regeneration factory. Accident examples at dangerous materials facilities - with FTA, pp.92-94 (1997).
Number of Deaths 8
Number of Injuries 4
Physical Damage 164.9 square meters of a steel cleaning building with a slate roof collapsed and was destroyed by fire. 203.2 square meters of a boiler room collapsed. The Roof of a 1500 cubic meters recovery tank was damaged. Neighboring buildings was damaged including broken windows. (Ministry of Labor).
Financial Cost ¥ 50 million (damage to buildings, 26 million yen, to contents, 24 million yen) (Fire and Disaster Management Agency)
Field Chemicals and Plants
Author KOSEKI, Hirosi (National Research Institute of Fire and Disaster)
YOSHINAGA, Jun (Graduate School of New Frontier Sciences, The University of Tokyo)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
Scenario