On December 3, 1984,
Union Carbide's pesticide-manufacturing plant in Bhopal, India leaked 40 tons
of the deadly gas, methyl isocyanate into a sleeping, impoverished community -
killing 2,500 within a few days, 10000 permanently disabled and injuring 100,000
people. Ten years later, it increased to 4000 to 7000 deaths and injuries to
600,000.
Risks
taken:
· Storage
tank of Methyl Isocyanate gas was filled to more than 75% capacity as
against Union Carbide‟s spec. that it should never be more
than 60% full.
· The
company‟s
West Virginia plant was controlling the safety systems and detected leakages
thro‟
computers but the Bhopal plant only used manual labour for
control and leak detection.
· The
Methyl Isocyanate gas, being highly concentrated, burns parts of body
with which it comes into contact, even blinding eyes and destroying lungs.
Causal
Factors:
•
Three protective systems out of
service
•
Plant was understaffed due to
costs.
•
Very high inventory of MIC, an
extremely toxic material.
•
The accident occurred in the early
morning.
•
Most of the people killed lived in a
shanty (poorly built) town located very close to the plant fence.
Workers
made the following attempts to save the plant:
•
They tried to turn on the plant
refrigeration system to cool down the environment and slow the reaction. (The
refrigeration system had been drained of coolant weeks before and never
refilled -- it cost too much.)
•
They tried to route expanding gases to a
neighboring tank. (The tank's pressure gauge was broken and indicated
the tank was full when it was really empty.)
•
They tried to purge the gases through a
scrubber. (The scrubber was designed for flow rates, temperatures and
pressures that were a fraction of what was by this time escaping from the tank.
The scrubber was as a result ineffective.)
•
They tried to route the gases through a
flare tower -- to burn them away. (The supply line to the flare tower
was broken and hadn't been replaced.)
•
They tried to spray water on the gases
and have them settle to the ground -- by this time the chemical reaction was
nearly completed. (The gases were
escaping
at a point 120 feet above ground; the hoses were designed to shoot water up to
100 feet into the air.)
In
just 2 hours the chemicals escaped to form a deadly cloud over hundreds of
thousands of people incl. poor migrant labourers who stayed close to the plant.
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