Explosion in the Process Reactor of a Silicon Production Plant
The accident occurred during the night during the production of a silicon oil- and additive-based waterproofing agent. A junior technician (hired 6 months back), recently assigned to this post, was left without supervision to manage a process modified very recently and executed only for the second time. In the process, the order of addition of reactants was not specified. The technician loaded first 800 kg of oil into the tank at first floor, started heating the reactor, and descended to the ground floor to pump the reagent. When going up to the second floor to fill a tank with water, he observed a kind of fog escaping from the tank. The explosion of the tank followed, caused by the formation of hydrogen (and perhaps also sodium hydride, NaH) from the decomposition of the silicon oil after the abrupt and uncontrolled addition of an extremely basic alcoholate (wrong pH control). The fire that ensued consumed 500 tonnes of chemicals (mainly alcohols), spread to significant part of the site (7,000 m2) and resulted in a huge cloud of smoke.The technician was severely injured, 2 responders injured and 15 intoxicated by CO during the emergency.
Event Date
June 8, 1988
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Immediate cause was a wrong procedure for chemical production process Root cause was the ill defined procedure, the insufficient training of personnel. Contributing causes was the unavailability of detailed and updated inventory of the chemicals stored on site and ill designed emergency plan.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
chemical reactor
Storage/Process Medium
Location Type
Location description
Industrial Area Near Inhabited Area
Pre-event Summary
The production process had been modified very recently and was executed for the second time only.
Lessons Learned
Lessons Learned
The inquiry discovered the following: 1. Measures to prevent recurrence: violation of the existing safety rules. 2. Measures to mitigate consequences: total lack of an internal emergency plan. 3. Emergency management: improvement needs were identified: among which the availability in higher quantities of the protection means; the need to assess quicker the type and amount of chemical risks for the surrounding, and an earlier quantitative detection of the atmospheric pollutions.
Event Nature
Emergency Action
3:00 The alarm is given by an habitant of the zone. 3:20 Intervention of the first professional fire brigade, not effective in fighting a fire of 500 t of different chemical products, including a majority of alcohols. 4:00 Evacuation of 200 habitants because the fire extends to a surface of 3 000 m, intensifies and generate a dark and toxic fume nitrogen oxides, ammonia, etc.) The high temperature helps the decomposition of the stored chemicals so that the concentrations of HCN, CO and halogens remain under control, and only CO et NOx are detected. 7:00 situation under control
Emergency Evaluation
The absence of retention devices, unused pipes and malfunctioning of the internal waste water treatment plant led to the disposal of the fire water (cyanide compounds, pentachlorophenols, etc.) into the neighboring river, which transported the polluted water into other rivers. .
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Description of the event in the European database eMARS
https://emars.jrc.ec.europa.eu/en/eMARS/accident/view/26029cf3-350b-494…
(accessed September 2020)
Event description in French database ARIA
https://www.aria.developpement-durable.gouv.fr/fiche_detaillee/161-2/
(accessed September 2020)