Report Bhopal

8/6/2019 Report Bhopal

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Introduction

Background about the original accident

The pesticide plant and the MIC release

Much information about the original Bhopal accident is available through books journal reports

case histories, documentaries proceedings from international conferences and the Internet. In

essence, about 41 metric tons of methyl isocyanate(MIC) was released from the Union Carbide

India Limited (UCIL) pesticide plant in Bhopal just after midnight on December 3, 1984. This

gas spread slowly southward from the plant site during the early morning hours with very stable

weather conditions. Of the 900,000 population within the city, over 200,000 people were

exposed to MIC tainted air. Documented death counts are listed at 3,787 .The number of

undocumented deaths will never be known, but estimates are over 10,000. Chaos surrounded the

city afterwards. Thousands panicked. As the story of the disaster circled the globe, international

aid began to flow into the city. Union Carbide, USA, was the majority owner of the plant

(50.9%) with Indian investors owning the rest. Warren Anderson, then chairman, made a

personal trip to the India to reach out, only to be placed under arrest. Several years later Union

Carbide settled with the Indian Government for over $470 million dollars plus other

considerations.

The event that caused the release was traced to a runaway reaction created by the contamination

of a storage tank of methyl isocyanate with a substantial amount of water. Although the safety

relief valve opened at design pressure, all downstream measures to mitigate an external release

of MIC to the surroundings were on stand-by (a caustic scrubbing tower) or out-of-service (a

flare tower). Furthermore, a water curtain spray designed to mitigate releases did not reach the

elevation of the release plume. Thus, MIC exited at an elevation from ground level of

approximately 35 meters for a period of 15 to 30 minutes. The cloud then descended to ground

level (MIC gas is approximately 2 times as dense as air), infiltrating the surrounding residential

areas (illegal shanty towns), and flowing slowly towards the center of Bhopal, located about 2

km to the south.



Product

Carbaryl

- Brand name Sevin (Union Carbide)- Third most used insecticide in US

- Not fatal to people- Does not cause cancer

Chemistry

TLV = 0.02 ppm

MethylIsocyanate



Methyl Isocyanate (MIC)

Effects of 0.4 ppm- Coughing- Chest pain

- Breathing pain (dyspnea)- Asthma- Eye irritation- Nose, throat, skin damage

Effects of 21 ppm- Lung oedema- Emphysema (damage of lung tissue)- hemorrhaging- bronchial pneumonia- death

Clear, colourless, b.p. 39o

C, odour threshold 2.1 ppmIf you smell it, there is too much!

40,000 kg were released in Bhopal on 3rd December 1984!

In 1970s

- Indian Government invites UCC to set up Sevin plant- Plant built in Bhopal to central location and transport

infrastructure- Indian Government has 22% stake in UCIL (UCC¶s

India Subsidary)- Plant initially approved for forumulation only (built in

area zoned for light industrial use)

In late 1970s and early 1980s

- Competition forces ³backward integration´. MIC manufactured at Bhopal site.- 10 times the daily use amount of MIC stored in plant- Drought causes drop in market demand for Sevin ± safety and maintenance lax- 6 minor accidents involving MIC between 1981 and 1984

- Plant conformed to much laxer standards than sister plant US



Explanation of the Possible Causes

Several causes have been proposed, two of which have been subjected extensive examination.

Cause 1 captioned in Fig. 2, is the admission of water via a water cleaning process where an

isolation valve existed but the line had not been blanked off (the ³Water Washing Theory). This

isolation valve was located about 300 m from the storage tanks via a pipeline. Substantial water

(500 kg plus line volume) with some head was required along with one other key valve leaking.

Cause 2 was sabotage, deliberately connecting a water hose to piping that directly entered into

the storage tank and deliberately admitted water. Cause 2 would have required intimate

knowledge of piping around the tank, where to physically make the correct connection, and the

removal of a pressure indicator and then the re-attachment of piping fittings.

Fig. 2. Overview of the piping system.

However, this is a basic cause. The root causes were management decisions:

� a decision to remove coolant from the refrigeration system used to cool the MIC storagetank.

� a decision to neglect a flare system in need of repair;

� a decision to place a scrubber system on stand-by to save on operating expenses;



And, there are additional root causes which made the incident more severe:

y inadequate emergency planning and community awareness;

y lack of awareness of the potential impact of MIC on the community by the peopleoperating the plant; lack of communication with community officials before and during

the incident.y inadequate community planning, allowing a large population to live near a hazardous

manufacturing plant. This situation was not unusual in the chemical industry in the early1980s, and one major impact of Bhopal was to warn all chemical plants about theimportance of these considerations in the site and operation of facilities.

Weaknesses/weak factors associated with the accident

i. Inadequate Maintenance

- During the incident, several safety equipments including scrubber and flare system did notoperated to control the leak. It shows that schedule maintenance procedure was notfollowed.

ii. Housekeeping Procedure Negligence

- Housekeeping procedure was not appropriately followed that led to the main cause of the

incident. During the incident, storage tank containing a large amount of MIC becomecontaminated with water, which eventually reacted to increase the MIC temperature pastits boiling point.

iii. Inappropriate Reaction Scheme Used

- The reaction scheme used at Bhopal plant is through Methyl Isocyanate (MIC) as anintermediate. This intermediate is very dangerous and its inventory should be minimized.An alternative reaction scheme (reaction route) that involves a less dangerousintermediate should be implemented.

iv. Weak Local Authority Enforcement

- A huge numbers of civilian residents were built near the plant site. Although the nearestcivilian residents were 1.5 miles away when the plant was constructed, because the plantwas the dominant source of employment in the area, shantytown eventually grew aroundthe immediate area. This shows a weak local authority enforcement to prohibit suchsituation from occurring.



Consequences of the accident

� Among the 500,000 people exposed to the gas:

± 20,000 have died till date

± 120,000 continue to suffer

� Out of every 3 children born after the Bhopal disaster, only 1 survived.

Conclusions

1. Every business decision has safety consequences.

2. A negative safety outcome is a negative business outcome.

3. In order to do the right thing, politics and the local community must be assessed, understood,and protected.



Appendix

Report Bhopal

Documents

Transcript of Report Bhopal