3 rd Dec 1984 25 years back

1. 3rd Dec 198425 years back Unforgettable day in the history of India

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

3. UNION CARBIDE

4. UNION CARBIDE IN INDIA • US Company • Manufacturing of Natural gases, Petrochemicals, Batteries, Automotives, Metal and Carbon products, etc • In 1924, a plant was set up in Calcutta to assemble battery components made in Britain.

5. Bhopal Plant • Setup in 1969 • To manufacture pesticide • The first batch of MIC was imported from the USA in 1973. • In 1979 this plant started to manufacture its own MIC. • Though the design of the MIC unit was based on Union Carbide's West Virginia plant, grossly lower standards were employed in the selection of construction material, monitoring devices and safety systems

6. METHYL ISOCYANATE • Highly reactive • Unstable and Flammable • Highly toxic • Reacts with acid, alkalies, water and variety of organic chemicals • Exothermic reaction • FP –18º C • BP 39º C • Reacts more violently when warm

7. What happened that night • A violent reaction was triggered as nearly 120-240 gallons of water entered the one of three tanks which had nearly 11,290 gal of MIC • It’s a hypothesis that during the process of washing the downstream of the filter pressure safety valves, the water might have entered one of the tank . • At 10:45 PM, the workers began to suffer eye and throat irritation • At 11:00 PM the control room operator noticed that the pressure in the tank has risen from 2 psig to 10 psig

8. What happened that night • MIC water reaction proceeded much rapidly • At 12.15AM the pressure in the tank has exceeded 30 psig. Seconds later the pressure was off the scale • The result was rapture of safety valve • MIC at the rate of 720 pounds/min at a pressure of 200 psig and temp of 200 ºC escaped into the vent scrubber which was out of function

9. What happened that night • From the scrubber the gas should have gone to flare tower, but the pipeline leading to flare tower was disconnected for maintenance. • So the gas directly entered the atmosphere • At 1:00AM the leathal clould was drifting towards the neighborhood of Bhopal killing people indiscriminately.

10. Major safety systems had deficiencies at the time of accident. • A 30 ton refrigeration unit to cool stored MIC, in order to prevent it from vaporizing or reacting. • A vent gas scrubber (VGS) to neutralize toxic gases with caustic soda in the event of a release. • A flare tower to burn vented gases from the MIC storage tanks and other equipment . • A water spray system to knock down escaping vapors.

11. MIC Storage Large volume of MIC stored in the plant. Storage above the safe recommended quantity Large bulk storage instead of token storage in individual containers MIC chosen on economic grounds CAUSES

12. SAFETY SYSTEMS 30 T refrigeration unit to cool stored MIC has been shut down since June 1984 Vent Gas Scrubber to neutralize toxic gases was turned off in Oct 1984 The flare tower was out of service Water spray system was not adequate and effective. CAUSES

13. MAINTENANCE Inadequate maintenance was a longstanding complaints Leaking valves , malfunctioning and broken gauges were common throughout the plant CAUSES

14. MANNING Operated with reduced man power (production crew from 12 to 6 and maintenance crew from 6 to 2) Workers were assigned jobs,they were not qualified for Untrained workers Signs and operating procedures were written in English CAUSES

15. CONSEQUENCES • HORRIBLE TO WATCH

22. THANK YOU .