Describe the Bhopal Gas Tragedy and its causes.

The Bhopal Gas Tragedy (2–3 December 1984) and Its Causes:

The Bhopal Gas Tragedy is the world's worst industrial chemical disaster, occurring at the pesticide manufacturing plant of Union Carbide India Limited (UCIL) in Bhopal:

• 1. Technical and Operational Causes of the Disaster:
  • Runaway Exothermic Reaction: Ingress of water into underground storage Tank 610 containing ~42 tonnes of volatile liquid Methyl Isocyanate (MIC - $CH_3NCO$).
  • Massive Chemical Pressurization: Rapid exothermic reaction raised tank pressure past safety limits ($>55 ext{ psi}$) and temperature $>200^circ ext{C}$, vaporizing toxic gas into the atmosphere.
  • Safety System Failures: Refrigeration cooling unit had been turned off to save electricity; Vent Gas Scrubber was inoperative; Flare Tower was disconnected for maintenance.
• 2. Catastrophic Human Toll:
  • Over 3,787 immediate deaths (official) and $>15,000 ext{–}20,000+$ long-term fatalities; over 500,000 people suffered permanent blindness, pulmonary fibrosis, and inter-generational birth defects.
• 3. Legislative Legacy: Prompted India to enact the comprehensive Environment (Protection) Act, 1986 and Public Liability Insurance Act, 1991.