| Case Name |
Fire caused due to incorrect opening of valves during sampling operation at a polypropylene manufacturing plant |
| Pictograph |
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| Date |
March 8, 1996 |
| Place |
Oita, Oita, Japan |
| Location |
Chemical factory |
| Overview |
There was a fire at a polypropylene manufacturing plant during usual operation. By opening two valves at the reactor outlet simultaneously, propylene and polypropylene particles were discharged into the atmosphere. It was apparently the result of human error. However, the problem was that a fail-safe or foolproof approach for preventing human error was not taken. There also might have been some omission in field management. |
| Incident |
A fire occurred due to an operation mistake on sampling at the reactor outlet of a polypropylene manufacturing plant. |
| Processing |
Manufacture |
| Individual Process |
Reaction |
| Process Flow |
Fig2.Unit process flow
|
| Substance |
Propylene, Fig3 |
| Polypropylene, Fig4 |
| Type of Accident |
Fire |
| Sequence |
A worker opened an air driven automatic valve of a degassing tank on the fifth floor to collect samples of polymer products in the reactor during usual operation. At that time, a fire occurred at the lower part of the sampling pot on the fourth floor. At this stage, the lower valve of the sampling pot on the fourth floor which should have been closed was open. (refer to Fig2) Degassing drum: A vessel installed at the polymerization reactor outlet to separate polypropylene particle products from the gas containing unreacted propylene gas.
Sampling pot: A small vessel installed beneath the degassing tank for sampling. |
| Cause |
At the reactor outlet, polypropylene particles coexisted with unreacted propylene gas. By separating the gas and the polymer particles in the high-pressure degassing drum, the polymer particles were removed at the bottom to the sampling pot with unreacted propylene gas. Then the mixture was depressurized and the gas was purged before sampling. In the sampling procedure, confirmation that the sampling valve was closed at the bottom of the sampling pot, which is the last task for preparations before sampling, was neglected. As the sampling valve was left open, polypropylene resin and propylene gas passed through the sampling pot from the degassing drum and spouted out through the sampling valve and the open inlet valve of the sampling pot. It is considered that the mixture was ignited by static electricity in the gas flow. |
| Response |
As an initial measure, emergency shutdown operation was done from CCR. In the field, water sprinkling with fixed fire fighting equipment, separation work, and nitrogen filling were carried out. In addition, water showering for cooling was carried out by 28 fire fighters and a disaster prevention crew using a high-place-pour-water engine and a chemical fire engine.
CCR: Central Control Room, a main instrument room or a control room of the plant. |
| Countermeasures |
Review of the reporting system to prevent a delay in reporting.
Improvement in the structure so that the bottom valve of a degassing drum cannot be opened while the valve at the lower part of the sample pot is closed. |
| Knowledge Comment |
It is difficult to eliminate confirmation errors. Introduction of fool-proof or fail-safe technology to prevent errors is important. |
| Background |
The main cause was human error. A valve that should have always been closed was not checked. However, a safety countermeasure can be easily taken by installing an interlock for an air valve to the sampling pot. |
| Incidental Discussion |
Although human error caused this accident, a fail-safe or fool-proof process to prevent accidents should be designed even if there is an operation error. This is a good example of an accident in which a fail-safe or foolproof system was neglected. |
| Reason for Adding to DB |
Example of fire caused due to simple incorrect operation of valves |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Insufficient Safety Measure, Carelessness, Insufficient Precaution, Carelessness of Operator, Ignorance of Procedure, Disregard of Procedure, Disregard of Operation Procedure, Planning and Design, Poor Planning, Wrong Structure of Sequence, Malicious Act, Rule Violation, Safety Rule Violation, Secondary Damage, External Damage, Leakage/Fire
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|
| Sources |
Fire and Disaster Management Agency, Fire when sampling in a polypropylene manufacturing plant. Accident cases of dangerous materials, 1996, pp.438-439.
Fire and Disaster Management Agency, Fire at polypropylene production plant, Letter from Assoc. for Safety Technic of Dangerous Materials. Special issue, pp.33-35(1997).
|
| Physical Damage |
A gas chromatography room on the 4th floor of the building and some analysis instruments in it were destroyed by fire. |
| Multimedia Files |
Fig3.Chemical formula
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Fig4.Chemical formula
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| Field |
Chemicals and Plants
|
| Author |
ARAI, Mitsuru (Environmental Science Center, The University of Tokyo)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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