33rdrd Dec 1984 Dec 1984

25 years back25 years back

Unforgettable day in the Unforgettable day in the history of Indiahistory of India

THE BHOPAL TRAGEDYTHE BHOPAL TRAGEDY

Methyl Isocyanate, a toxic gas Methyl Isocyanate, a toxic gas released from the Union Carbide released from the Union Carbide factory factory killed over 8,000 people in its killed over 8,000 people in its immediate aftermath and caused immediate aftermath and caused multi-systemic injuries to over multi-systemic injuries to over 5,00,000 people.5,00,000 people.

UNION CARBIDEUNION CARBIDE

UNION CARBIDE IN INDIAUNION CARBIDE IN INDIA

US CompanyUS CompanyManufacturing of Natural gases, Manufacturing of Natural gases,

Petrochemicals, Batteries, Petrochemicals, Batteries, Automotives, Metal and Carbon Automotives, Metal and Carbon products, etcproducts, etc

In 1924, a plant was set up in In 1924, a plant was set up in Calcutta to assemble battery Calcutta to assemble battery components made in Britain.components made in Britain.

Bhopal PlantBhopal Plant Setup in 1969Setup in 1969 To manufacture pesticideTo manufacture pesticide The first batch of MIC was imported from The first batch of MIC was imported from

the USA in 1973. the USA in 1973. In 1979 this plant started to manufacture In 1979 this plant started to manufacture

its own MIC. its own MIC. Though the design of the MIC unit was Though the design of the MIC unit was

based on Union Carbide's West Virginia based on Union Carbide's West Virginia plant, grossly lower standards were plant, grossly lower standards were employed in the selection of construction employed in the selection of construction material, monitoring devices and safety material, monitoring devices and safety systemssystems

METHYL ISOCYANATEMETHYL ISOCYANATE

Highly reactiveHighly reactive Unstable and FlammableUnstable and Flammable Highly toxicHighly toxic Reacts with acid, alkalies, water and Reacts with acid, alkalies, water and

variety of organic chemicalsvariety of organic chemicals Exothermic reactionExothermic reaction FP –18FP –18ºº C C BP 39BP 39º Cº C Reacts more violently when warmReacts more violently when warm

What happened that nightWhat happened that night A violent reaction was triggered as nearly A violent reaction was triggered as nearly

120-240 gallons of water entered the one 120-240 gallons of water entered the one of three tanks which had nearly 11,290 of three tanks which had nearly 11,290 gal of MICgal of MIC

It’s a hypothesis that during the process It’s a hypothesis that during the process of washing the downstream of the filter of washing the downstream of the filter pressure safety valves, the water might pressure safety valves, the water might have entered one of the tank . have entered one of the tank .

At 10:45 PM, the workers began to suffer At 10:45 PM, the workers began to suffer eye and throat irritationeye and throat irritation

At 11:00 PM the control room operator At 11:00 PM the control room operator noticed that the pressure in the tank has noticed that the pressure in the tank has risen from 2 psig to 10 psig risen from 2 psig to 10 psig

What happened that nightWhat happened that nightMIC water reaction proceeded MIC water reaction proceeded

much rapidly much rapidly At 12.15AM the pressure in the At 12.15AM the pressure in the

tank has exceeded 30 psig. tank has exceeded 30 psig. Seconds later the pressure was Seconds later the pressure was off the scaleoff the scale

The result was rapture of safety The result was rapture of safety valvevalve

MIC at the rate of 720 MIC at the rate of 720 pounds/min at a pressure of 200 pounds/min at a pressure of 200 psig and temp of 200 psig and temp of 200 ºC escaped ºC escaped into the vent scrubber which was into the vent scrubber which was out of functionout of function

What happened that nightWhat happened that night

From the scrubber the gas should From the scrubber the gas should have gone to flare tower, but the have gone to flare tower, but the pipeline leading to flare tower was pipeline leading to flare tower was disconnected for maintenance.disconnected for maintenance.

So the gas directly entered the So the gas directly entered the atmosphereatmosphere

At 1:00AM the leathal clould was At 1:00AM the leathal clould was drifting towards the neighborhood drifting towards the neighborhood of Bhopal killing people of Bhopal killing people indiscriminatelyindiscriminately..

Major safety systems had Major safety systems had deficiencies at the time of accident.deficiencies at the time of accident. A 30 ton refrigeration unit to cool stored A 30 ton refrigeration unit to cool stored

MIC, in order to prevent it from vaporizing MIC, in order to prevent it from vaporizing or reacting.or reacting.

A vent gas scrubber (VGS) to neutralize A vent gas scrubber (VGS) to neutralize toxic gases with caustic soda in the event toxic gases with caustic soda in the event of a release.of a release.

A flare tower to burn vented gases from the A flare tower to burn vented gases from the MIC storage tanks and other equipmentMIC storage tanks and other equipment . .

A water spray system to knock down A water spray system to knock down escaping vapors.escaping vapors.

CAUSESCAUSES

MIC StorageMIC Storage Large volume of MIC Large volume of MIC stored in the plant.stored in the plant.

Storage above the safe Storage above the safe recommended quantityrecommended quantity

Large bulk storage Large bulk storage instead of token storage instead of token storage in individual containersin individual containers

MIC chosen on economic MIC chosen on economic groundsgrounds

CAUSESCAUSES

SAFETY SAFETY SYSTEMSSYSTEMS

30 T refrigeration unit to 30 T refrigeration unit to cool stored MIC has been cool stored MIC has been shut down since June 1984shut down since June 1984

Vent Gas Scrubber to Vent Gas Scrubber to neutralize toxic gases was neutralize toxic gases was turned off in Oct 1984turned off in Oct 1984

The flare tower was out of The flare tower was out of serviceservice

Water spray system was not Water spray system was not adequate and effective.adequate and effective.

CAUSESCAUSES

MAINTENANCEMAINTENANCE Inadequate Inadequate maintenance was a maintenance was a longstanding longstanding complaintscomplaints

Leaking valves , Leaking valves , malfunctioning and malfunctioning and broken gauges were broken gauges were common throughout common throughout the plantthe plant

CAUSESCAUSES

MANNINGMANNING Operated with reduced man Operated with reduced man power (production crew from power (production crew from 12 to 6 and maintenance crew 12 to 6 and maintenance crew from 6 to 2)from 6 to 2)

Workers were assigned Workers were assigned jobs,they were not qualified jobs,they were not qualified forfor

Untrained workersUntrained workers Signs and operating Signs and operating

procedures were written in procedures were written in EnglishEnglish

CONSEQUENCESCONSEQUENCES

HORRIBLE TO WATCHHORRIBLE TO WATCH

THANK YOUTHANK YOU

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