Fires reported at a chemical plant east of Houston, which was inundated by forty inches of rain dropped by Hurricane Harvey, highlight in the starkest possible terms the need to exercise all precautions in securing equipment and safety and restarting operations at flood-affected facilities with hazardous chemicals. The U.S. Chemical Safety and Hazard Investigation Board (CSB) is particularly concerned about restart.
Houston and surrounding areas, extending into Louisiana are densely populated by large petrochemical facilities.
“Over the coming weeks and months, [oil refineries and chemical plants] will be restarting,” states the CSB. “This is a time to make sure no lives are needlessly claimed by this tragedy and no further delays occur in the production of essential transportation fuels and chemicals. Facilities should pay particular attention to process safety requirements during this critical period to assure a safe and expeditious return to operation.”
Organic peroxide fires
The fires occurred at Arkema Inc.’s Crosby, Texas, plant. According to an Arkema statement, flooding caused loss of power and shut-down of refrigeration systems and also rendered backup emergency generators inoperable. The plant manufactures organic peroxides, which are highly flammable and burn if not maintained at low temperatures. Arkema said that after consultation with local public officials, it was decided that the best approach was to let the fires burn out. Based on their assessment of the situation, local officials had previously established a 1.5-mile evacuation zone surrounding the plant.
Higher level of attention
The CSB alert notes that starting up a complex petrochemical process requires establishing stable flows, levels, temperatures, and pressures within large-scale equipment.
“Startup requires and receives a higher level of attention and care than normal processing because numerous activities are occurring simultaneously and many automatic systems are run under manual control,” says the CSB.
The alert includes a number of checklists containing general guidance for safe startup. Points of paramount importance include:
- Using appropriate management-of-change processes before modifying any startup procedures, equipment, or staffing arrangements due to the impact of the hurricane.
- Making sure that adequate staffing and expertise are available before starting up, recognizing that human performance may be compromised due to crisis conditions.
- Evacuating nonessential personnel (including personnel in trailers) from the vicinity of process units that are starting up.
Equipment checks
Short checklists for “thoroughly reviewing” process equipment are included in the alert. Equipment damage that may be caused by flooding include voids created under tanks that may compromise stability; floodwater leakage into tanks; loss of insulation in furnaces; floodwater damage to many types of electric motors and drives; and debris and silt obstruction in sewers and drains.
“The lists are not exhaustive and are not intended to substitute for any other procedures or checklists regularly used or developed in response to Hurricane Harvey,” notes the CSB.
The CSB’s safety alert is here.