Preview-Amongst the worst Industrial Disasters ofits time.• Occurrence: 3rd December 1984.• Place of occurrence: Bhopal, Madhya Pradesh, India.• Company: Union Carbide Corporation.• Chemical: Methyl Isocyanate (40 tons)• People Affected- >500,000• People Died- ~40,000
About 550,000 people were exposed to the gas. A government affidavit in 2006 stated the leak caused 558,125 INJURIES including 38,478TEMPORARY PARTIAL INJURIES and approximately 3,900 SEVERELY AND PERMANENTLY DISABLING INJURIES
Bhopal Scenario Union Carbide Corporation Plant
About Union Carbide Corporation(UCC) • Started in 1969 in bhopal • Phosgene, Monomethlyamine, Methyl Isocyanate (MIC) and the pesticide carbaryl, also known as Sevin. • Taken over by DOW Chemicals in 2001. • DOW refused Union Carbide’s Liabilities in Bhopal, India.
All safety system fails due to poor maintenance.
MIC STORAGE TANKPicture shows the tank as it is today.
TANK SAFETY FEATURES• A Nitrogen line was connected to the tank to transfer the product byinert pressurization of the headspace.• The tank was fitted with a pressure relief valve and rupture disc. Thevent line from the valve exhausted into a scrubbing tower filled withcaustic soda (NaOH). This would neutralize the MIC to form Sodiumisocyanate. Any residual gas from the scrubber was sent to a 30 m tallflare stack where it would be burned off.• There was an external coiled jacket on the vessel through which coolant(freon / chloroform) was re-circulated. This was to keep the vesselcontents at 0 C and thus prevent any adverse exothermic reactionsoccurring.• Tanks were not to be filled above the 50 % mark so that in the event ofdangerous chemical reactions occurring, solvents could be pumped in toquench the reactions.
ACCIDENT DESCRIPTIONPipe Cleaning ProcedureAs part of routine procedures, the pipes leading from the MICdistillation column to the storage tanks were regularly flushed withpressurized water. MIC and any associated products can be quitecorrosive and could form corrosion deposits in the pipe. These depositswould contaminate the MIC in the tanks and could initiate unwantedreactions. During cleaning, valves in the product lines were to be closedand a blank or slip-blind placed in the product line leading to the storagetank to prevent contamination.However the valves, although closed, were not sealing properly becauseof corrosion and the maintenance crew forgot about the blank. Itappears that about 1000 kg of water plus metal debris entered tank 610.Assuming all the previously described safety features were operative,this should not have been a catastrophic occurrence.
Effects on Human Health. • Respiratory Disorders – Irritation to the lungs, causing coughing and/or shortness of breathing. Higher exposure caused build up of fluids (pulmonary enema). Caused Asthma. • Cancer Hazard – Caused mutation (genetic changes). It caused cancer. • Reproductive Hazard – Association between exposure to Methyl isocyanate and miscarriages. It may damage the growing fetus. May also affect fertility in men and women. • After Effect- Traces of many toxins were found in the Brest Milk of mothers and were in turn transmitted to the recipient babies.
Animal Slaughter 2,000 buffalo, goats, and other animals died.
Toxic Materials in Soil and Water• Lead, Nickel, Copper, Chromium, hexachlorocyclohexane and chlorobenzenes were found in soil samples.• Mercury was found to be between 20,000 to 6,000,000 times the standard level in soil.
Chemicals Dumped by Union Carbide in Bhopal S.No Chemical Amount Use in factory Nature of original pollution 1 Methylene Chloride 100 MT Solvent Air 2 Methanol 50 MT Solvent Air 3 Ortho-idichlorobenzene 500 MT Solvent Air, Water, Soil 4 Carbon tetrachloride 500 MT Solvent Air 5 Chloroform 300 MT Solvent Air 6 Tri methylamine 50 MT Catalyst Air 7 Chloro benzyl chloride 10 MT Ingredient Air, Water, Soil 8 Mono chloro toluene 10 MT Ingredient Air, Water, Soil 9 Toluene 20 MT Ingredient Air, Water, Soil 10 Aldicarb 2 MT Product Air, Water, Soil 11 Carbaryl 50 MT Product Air, Water, Soil 12 Benzene Hexachloride 5 MT Ingredient Air, Water, Soil 13 Mercury 1 MT Water, Soil 14 Mono methyl amine 25 MT Ingredient Air 15 Chlorine 20 MT Ingredient Air 16 Phosgene 5 MT Ingredient Air 17 Hydro chloric acid 50 MT Ingredient Air, Soil 18 Chloro sulphonic acid 50 MT Ingredient Air, Soil 19 Alpha Naphthol * 50 MT Ingredient Air, Soil 20 Napthalin 50 MT Ingredient Air 21 Chemical waste Tar 50 MT Waste Water, Soil 22 Methyl Isocyanate 5 MT Ingredient Air, Water, Soil
Toxic materials found in Soil and Water afterthe accident Benzene, oxides 7, 890 Dichlorobenzenes 87,500 Polynuclear Aromatic 2,340 Hydrocarbons Phthalates 9,940 Trichlorobenzenes 9,410 Trimethyl Trianzintrione 24,470 1-Napthalenol 59,090 Units in parts per billion (ppb) Additionally, Dichlorobenzene and Trichlorobenzenes were found in the soil and water samples.
Compensation and Legal Aspects• Compensation of $470 million ($500 per dead).• Twenty years of passiveness.• Case was reviewed and put up in American Court.• DOW Refused Union Carbide’s Liabilities in Bhopal, India.• In order to provide safe drinking water to the population around the UCIL factory, Government of Madhya Pradesh presented a scheme for improvement of water supply.• Supreme court directed the UCC and M.P. govt. to take immediate steps for disposal of toxic waste lying around and inside the factory.
20,000 KILLED550,000 SEVERELY AFFECTED …And you thought only weapons could cause Mass Destruction.