Transitions - Sustainable Design: The Science of Sustainability and Green Engineering - page 111

A new employee was told by a supervisor to clean out connectors to the
storage tanks. The worker closed the valves properly but did not insert
safety disks to prevent the valves from leaking. In fact, the worker knew
the valves were leaking but believed that they were the responsibility of
the maintenance staff. Also, the second-shift supervisor position had been
eliminated, meaning one less source of safety information was available to
workers.
When the gauges started to show unsafe pressures, and even when the
leaking gases started to sting the mucous membranes of workers, they found
that evacuation exits were not available. There had been no emergency drills
or evacuation plans.
The primary fail-safe mechanism against leaks was a vent-gas scrubber.
Normally, this release of MIC would have been sorbed and neutralized
by sodium hydroxide (NaOH) in the exhaust lines, but on the day of the
disaster, the scrubbers were not working. (The scrubbers were deemed
unnecessary, since they had never been needed before.)
A flare tower to burn off any escaping gas that would bypass the scrubber
was not operating because a section of conduit connecting the tower to the
MIC storage tank was under repair.
Workers attempted to mediate the release by spraying water to 100 feet, but
the release occurred at 120 feet.
Thus, according to the audit, many checks and balances were in place, but
cultural considerations were ignored or given low priority, such as the need to
recognize differences in land-use planning and buffer zones in India and in West-
ern nations, and the differences in training and oversight of personnel in safety
programs. Every engineer and environmental professional needs to recognize that
much of what we do is affected by geopolitical realities, and that we work in a
global economy. This means that we must understand how cultures differ in their
expectations of environmental quality. One cannot assume that a model that works
in one setting will necessarily work in another without adjusting for differing
expectations. Bhopal demonstrated the consequences of ignoring these realities.
Smaller versions of the Bhopal incident are more likely to occur, but with more
limited impacts. For example, two freight trains collided in Graniteville, South
Carolina, just before 3:00 A.M. on January 6, 2005, resulting in the derailment of
three tanker cars carrying chlorine (Cl 2 ) gas and one tanker car carrying sodium
hydroxide (NaOH) liquids. The highly toxic Cl 2 gas was released to the atmo-
sphere. The wreck and gas release resulted in hundreds of injuries and eight deaths.
In February 2005, the District of Columbia city council banned large rail
shipments of hazardous chemicals through the U.S. capital, making it the first
large metropolitan area in the United States to attempt to reroute trains carrying