Bhopal Disaster-Case Study

8/11/2019 Bhopal Disaster-Case Study

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Welcometo

Presentation

on

Bhopal Disaster

Case Study

by

P.C. VenkateswarluSecretary

National Safety Council,

Karnataka Cha ter - Ban alore.


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UNION CARBIDE CORPORATION - BHOPAL


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WHAT HAPPENED ?

A worst accident in the history of thechemical industry occurred in the UnionCarbide plant at Bhopal on 3 December1984, when a leak of 25 t of methylisocynate (MIC) from a storage tank spreadbeyond plant boundary, killing about 2000

people and injuring over 200000 people.Most of them were living in a shanty townthat had grown up close to the plant.


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WHAT HAPPENED ?


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HOW IT HAPPENED ?

The tragedy started when a tank of MIC, anintermediate used in the manufacture ofinsecticide became contaminated with waterand a runaway reaction occurred.

Temperature and pressure rose, relief valveopened and MIC vapour discharged into

atmosphere.


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WHAT WENT WRONG ?

The protective equipment which should haveprevented or minimized the discharged wasout of action or not in full working condition.

The refrigeration system which should havecooled storage tank was shutdown.

The scrubbing system which should haveabsorbed the vapour was not available.

The flare system which should have burntvapour was out of use.


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Gas Vent Scrubber Gas Vent Scrubber Stack


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WHY DID RUNAWAY REACTION OCCUR ?

MIC storage tank became contaminated bysubstantial quantities of water andchloroform which led to runaway reactions, arise in temperature and pressure anddischarge of MIC vapour from storage tank.

One theory is that water came from a section

of vent line that was being washed out.

This vent line should have been isolated by aslip plate which was not done.


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LESSONS LEARNT

What you donthave, cantleak :MIC which was an intermediate, not a productor raw material, need not have been there at

all.Originally MIC was imported and had to bestored but later it was manufactured on site.

Over 100 t were in store at the time of tragedyInstead of storing in tanks there can be only5-10 kgs. in a pipe line.

Mitsubishu were said to be doing this already.


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LESSONS LEARNT

Plant Location :The death toll at Bhopal would have beenmuch smaller if a shanty town had not been

allowed to grow up near the plant.It the government cannot control their growth,the industry should be prepared to buy theland and fence it off.


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LESSONS LEARNT

Safe Design :Since it is well known that water reactsviolently with MIC no water should have been

allowed anywhere near the equipment, forwashing out lines or for any other purpose.

If water is not there, it cannot leak in, nomatter how many valves leak or how many

errors are made.

This is another example of inherently saferdesign.


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LESSONS LEARNT

Whatever you have, you should maintain ingood working condition :

The storage tank was fitted with refrigerationsystem but this was not in use.

The scrubbing system which should have absorbedMIC was not in working condition.

The flare system which should have flared MIC

was disconnected for repair.

The high temperature and pressure on MIC tankdid not operate as the instruments were poorly

maintained and therefore unreliable.


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LESSONS LEARNT

Joint Venture :The Bhopal plant was half owned by US company,Union Carbide and half owned by Indians.

Although Union Carbide designed and installed,the Indian company was responsible foroperations.

It was not clear who is responsible for design and

operation.


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LESSONS LEARNT

Handling Emergencies :Bhopal incident showed the deficiencies in theprocedures for handling emergencies both by thecompany and local authorities.

Public Response :

Public responded poorly when there was gasleakage. They ran in wrong directions to escape

from the gas.


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WHAT DID WE DO ?

The Factories Act, 1948 was amended in1987 to include the following

Section 41A : Constitution site appraisal

committee.Section 41B : Compulsory disclosure of information

by the occupier.

Section 41C : Specific responsibility of the occupierin relation to hazardous processes.

Section 41D : Power of Central Government to

appoint inquiry committee.


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WHAT DID WE DO ?

The Factories Act, 1948 was amended in1987 to include the following

Section 41E : Emergency standards

Section 41F : Permissible limits of exposure of

chemical and toxic substances

Section 41G : Workersparticipation in Safety

Management.

Section 41H : Right of workers to warn about

imminent danger


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DID WE REALLY LEARNLESSONS ?


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ThanQ

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Bhopal Disaster-Case Study