| | |
| |
|
|
|
Go back to the accident listing
|
You do not have a membership or you are not logged in
Become a member
|
|
General accident information
|
| Class/Quality |
* * * * |
| Year |
1999 |
| Summary |
Presence of highly flammable
Liquid in mixing tank have
Formed an explosive mixture
Causing explosion & 1 casualty |
| Country |
D |
| Activity |
WASTE-TREATMENT |
| Location |
CHEMICAL FACTORY |
| Chemicals |
Iron(3) chloride solution, Sewage and/Or waste water, Sulphuric acid (sfa), Toluene (toluol/Methylbenzene) |
| Cause |
Unknown-cause |
| Fatalities/Injuries |
1 / 1 |
| Occurrences or events |
Chemical reaction, Defective-working, Emergency-stop, Evacuation,
Explosion, Fire fighting/Emergency response, Human-operations, Ignition,
Mix, No-action, Pump-over, Safety-measures,
Wrong-composition |
|
|
| |
Full accident information
|
Click here to view a document containing the full accident information
|
Country: (WEST) GERMANY (D)
Date : 1999 1112
Twelve tons of process water effluents from a receiver were transferred into a mixing tank and treated with 150/kg of solid iron chloride (FeCl3) in sulphuric acid (60%), setting pH 2.5-3.0. The pH was controlled by taking a sample with a manual sampler and tested with portable pH testing equipment externally to the tank. After the third test, the pH was at 2.9, corresponding to default parameters. The operator in charge decided to perform a last test after a short stirring time, in order to guarantee a stable pH value. According to the analysis of the damage, an explosion occurred in the gas space of the mixing tank (the presence of a highly flammable liquid in the mixing tank must have formed an explosive vapour-air mixture in the gas space of the tank). The operator in charge, standing in front of the opened manhole, was fatally injured by the explosion. Hydrogen peroxide 35%, which according to operating instructions had to be fed in after setting the pH value, had still not been added due to the fact that the manual pH test had not been concluded. The meeting in time and space of an ignitable explosive atmosphere with an ignition source has to be traced back to a deviance in the operating conditions and was not to be expected in that form.
Material damages are estimated at 2E+6 D marks (1E+6 EURO).
Lessons learned
1.
The preliminary treatment of sewage water will be carried out in a purged tank.
2.
Raw materials are fed into a closed system.
3.
Sampling will not be performed any more on an open tank.
|
|
|
|
|
| |
| | |