| Case Name |
Leakage of heat medium oil from a varnish manufacturing plant caused due to an error in judgment and a mistake in operation at startup |
| Pictograph |
|
| Date |
November 30, 1992 |
| Place |
Kawasaki, Kanagawa, Japan |
| Location |
Chemical factory |
| Overview |
At a manufacturer in Kanagawa prefecture, heating medium oil for heating/cooling of reactors for varnish production spilled into the sea via a public sewer. It had leaked through a vacuum pump exhaust line and a water purge line from the varnish manufacturing plant. This leakage resulted from an error in operation of an oil supply pump and negligent temperature control, ignoring the standards of operation procedure. |
| Incident |
Hot medium oil leaked into the sea from a varnish production plant caused by ignorance of procedure on starting heating medium operation. |
| Processing |
Manufacture |
| Individual Process |
Other |
| Process Flow |
Fig2.Unit process flow
|
| Substance |
Alkylnaphthalene |
| Type of Accident |
Leakage, environmental pollution |
| Sequence |
On November 30th, 1992, 08:40 Preparation of heating medium oil started for heating and cooling a reactor for varnish manufacturing.
08:45 A circulating pump and a vacuum pump operation started to remove water in heating medium oil in a flush tank.
08:50 A heater for heating medium oil was switched on.
08:55 A feed pump was switched on and supply of heating medium oil to the flush tank started.
09:00 The temperature of the flush tank reached 160 °C, but the heater was not turned off. It was to be turned off when the temperature reached 130 °C during standard operation.
0910 The vacuum pump was turned off and an air vent valve was opened. Heat medium oil leaked from the exhaust line of the vacuum pump and spilled into the drain. The oil escaped into the sea via a public sewer.
Refer to Fig2 |
| Cause |
1. The standard of operation procedure was ignored: heating medium oil should not be supplied when a vacuum pump for a flush tank is working. Supplied oil leaked through the vacuum pump because valves were not set correctly.
2. Heating of oil for removing water should be stopped at a temperature between 130 °C and 150 °C. The standard of operating procedure was ignored and the temperature reached 160 °C. This negligence resulted in escaping of oil vapor through the vacuum pump, and it was condensed by cooling.
3. There were no facilities to prevent oil leakage to the drain at the end of the exhaust line of the vacuum pump. |
| Response |
The oil heater was turned off. |
| Countermeasures |
1. Improving the standards of operation procedure.
2. Providing thorough education for employees.
3. Installing an interlock.
4. Installing an oil mist trap to the vacuum pump exhaust line.
5. Installing a drainage sensor.
6. Remodeling a receiving drum for an oil mist. |
| Knowledge Comment |
Only the foreman understood the whole procedure, and each operator concentrated on his own task of the operation. This might have been the cause of the accident. All of the operators should be educated to understand the whole operation. |
| Background |
1. The foreman forgot the standard of operating procedure.
2. Operators know only their individual jobs and did not understand the whole picture of the operation and the hazard they might face because adequate education was not given.
3. There was no oil trapping facilities at the end of the vacuum pump, which must be a mistake in construction design.
4. After all, safety management of the company was inadequate. |
| Reason for Adding to DB |
Example of leakage of heat medium oil into the sea caused due to inadequate operating procedure without confirming tasks before work |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Insufficiet Safety Measure, Carelessness, Insufficient Precaution, Insufficient Confirmation, Planning and Design, Poor Planning, No facicity against Leakage, Regular Operation, Erroneous Operation, Valve was not Closed Tightly, Secondary Damage, Damage to Environment, Environmental Pollution
|
|
| Sources |
High Pressure Gas Safety Inst. of Japan. High-pressure gas protection overview. pp.234-235(1994).
National dangerous material safety association. Leakage caused by error in heating medium oil operation at insulating varnish manufacturing facility. 100 cases of accidents at dangerous facilities -No.2-. pp.125-126(1994).
Kawasaki City Fire fighting station Prevention division Peace section. Outline of leakage accident of heating medium at T Co. C factory. Material of the Kawasaki City Complex safety countermeasures committee.
|
| Financial Cost |
¥250,000 (Material of the Kawasaki City Complex safety countermeasures committee) |
| Consequences |
About 20 liters of heat medium oil leaked into the sea. |
| Field |
Chemicals and Plants
|
| Author |
YOSHINAGA, Jun (Graduate School of New Frontier Sciences, The University of Tokyo)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
|
