Toxic Vapor Released

Safety Incident Topic : Vent of styrene vapors
Location Of Incident : Wingles, france
Date Of Incident : 28th, April 2006


Brief Account Of Incident
the reactor was vented for 10 minutes while full cooling At 8h00 pm , April 28, 2005 , an operational problem due to too a high polymer melt viscosity led to a an emergency shut-down of crystal line n° 2 in Wingles site. As per the emergency procedure, rarely used, was applied . The estimated vapor release is 1.3 t . Under weak windy conditions, styrene odors were detected by neighborhood community. Fire brigade has been called for enquiry. The odor disappeared within 30 minutes and the operations were successfully and safely stopped. The French Regulations Authorities have been informed. To date, no contact from the media.

Potential Outcome
Environmental and health nuisances; damage to BP image .

What Went Wrong (Critical Factors)
- Lack of judgment : The control room operator increased the contents of one reactor which led to the process upset.
- No use of fire water gyromonitors which would have decreased partially the consequences of the vent via condensation of the vapors .
- Inadequate safety devices No means to catch or condense the vapors during an emergency reactor vent .
- Equipment - Other: The contents of the reactors were fairly high and possibly outside the operating window.
- Inadequate Recall of Training Material: There was no evidence that the operator was aware of the consequences of increasing the contents of the reactor .
- Inadequate correction of prior incident: a similar incident occurred in June 2001 .No adequate corrective action was taken.
- Inadequate technical design: The design input was obsolete.
- Procedures: - This critical factor refers to the operating window of the process. Potential situation not covered: the emergency procedure does not call for fire water use in case of venting .

What Went Well
1· The duration of venting was properly managed and reduced to the minimum
2· The plant fire brigade was responding well
3· Good internal and external communication

Lessons Learned
- Operators should be remembered / trained regarding the hazards of running the process close to the operating window.
- Although venting of the reactor is part of the emergency procedure, the potential consequences were not sufficiently assessed. Adequate safety devices will be provided .

Key Messages
Emergency VOC vent to the atmosphere is no longer tolerated .Risk assessment should be conducted to avoid the consequences of such incidents