report on bhipal gas disaster

8/2/2019 Report on Bhipal Gas Disaster

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BIRLA INSTITUTE OF TECHNOLOGY &

SCIENCES

PILANI-333031

DISASTER MANAGEMENT

REPORT

On

BHOPAL GAS DISASTER

Submitted by Prepared for

Santosh Kumar Gupta Dr. Rajiv Gupta


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ABSTRACT

The most influential process safety accident passed its 20th anniversary on Dec 3, 2004. At an

international symposium to mark the event in Kanpur, India during the week of this anniversary,

process safety practitioners from around the world assembled to discuss progress in resolving the

Bhopal tragedy and in advancing the practice of process safety worldwide. This paper reports the

main conclusions from the conference, and provides insight into the Bhopal site as attendees found

it in December 2004. Since 1984, many positive steps worldwide have been made in regards to

improvements in process safety and protection of personnel within chemical plants and of people in

the surrounding communities. However, little progress has been made in decommissioning and

decontaminating the Bhopal plant site, now under control of the Indian state of Madhya Pradesh.

Many plant chemicals, abandoned there in 1985, were still at the site in 2004, mostly in sub-

standard storage conditions. Mitigation recently commenced, but unconfirmed reports of the

mitigation methods are concerning. The lesson learned: we all have a responsibility to insure that

events which follow a chemical accident reach a proper conclusion; and that no further undue

suffering results to the general public and our fellow employees.

Key Words-

UCC, MIC, Mitigation, UCIL, ICMR, TISS, HCN.SEVIN, CSIR Etc


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1.INTRODUCTION

The worlds worst industrial disaster occurred in Bhopal on the night of December 23, 1984.

An explosion at the Union Carbide India Limited (UCIL) pesticide plant resulted in the releaseof 3040 tons of a toxic gas, methyl isocyanate (MIC) spreading over approximately 30 squaremiles, killing thousands of people and injuring hundreds of thousands . A large number of theinhabitants in the township of Bhopal were exposed to different degrees, depending on theirproximity to the plant and atmospheric factors; in fact there are more than 500 000 registeredsurvivors of the tragedy. The unprecedented mortality and morbidity due to the accidentgenerated global scientific interest and a spectrum of multi-systemic studies were conducted onexposed individuals. Significant number of studies was conducted on varied aspects, but thepublished work has largely been restricted to histo-pathological findings, especially of lungs andsmall cross-sectional studies delineating symptomatology and clinical morbidity in the survivors.The Indian Council of Medical Research (ICMR) was one of the foremostorganizations to initiate clinical research studies on the affected population. It has recentlypresented its first technical report of the research findings on the Health Effects of the ToxicGas Leak from the Methyl Isocyanate Plant. in Bhopal gleaned out of the 24 research projectscarried out between 1985 to 1994 . As part of the ICMR investigations, epidemiological, clinicaland toxicological studies were carried out on 80 000 persons at severely, moderatelyand mildly exposed areas and compared with controls from unexposed areas. According to theICMR report, nearly three-fourth of the deaths occurred within the first 72 hours of the leak.Though the number of deaths declined rapidly, the extent of the impact on the survivors heal thwas compounded by the fact that nothing was known about the toxic effects of MIC, hence therewas no clue about a possible antidote to minimize the impact. According to ICMR,a large fraction of the exposed population continues to be chronically ill with diseases of therespiratory, gastro-intestinal, reproductive, musculoskeletal, neurological and otherSystems. It must be noted that scientific work has been published after this report that not onlysummarizes the health effects of MIC but also highlights the limitations of the studies published.This and many other commentaries have strongly emphasized the need for continued vigilancefor the long term ill effects of MIC.

The multi-disciplinary study of histopathology and toxicology of Bhopal gas tragedy resolvedseveral issues. First, the progression of severe pulmonary oedema to chronic fibrosis wasconfirmed experimentally, following a single exposure to MIC. Analysis of the residue in Tank610 revealed over 21 chemicals. Apart from MIC and HCN, some of them were tracked down tothe blood and viscera of dead and living exposees. The rationale of NaTS therapy was

substantiated by elevated urinary NaSCN levels in Double Blind Clinical Trials as well aspatients. Apart from cyanide, the cherry red discoloration was also shown to result frombinding of MIC to end-terminal valine residues of Hb, as shown by changes in 23DPG levelsand blood gas profiles.


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1.1 Nature of Toxic Gases

Public attention to the high reactivity of MIC was drawn by Devkumar and Mukherjee. It wasfollowed by more authoritative accounts in the Varadarajan Committee Report. According to thereport, there was a massive leak of MIC stored for a long period in the incriminated Tank 610 ofthe Pesticide Plant of Union Carbide of India Ltd (UCIL). Several hypotheses attributed for thisdisaster include, prolonged bulk storage of 42 tons of MIC, nonfunctioning refrigeration system,failure of safety measures and malfunctioning of neutralization facilities. Oneor more of these factors might have contributed to the accidental and uncontrolled runawayreaction. From all accounts, quite unlike leakage of a single chemical like ammonia, sulphuricacid, phosgene or hydro cyanic acid, the gas release in Bhopal is not due to mere leakage of coldMIC. The presence of an array of multiple chemicals was demonstrated57. Careful re-examination by the toxicology project of the ICMR, revealed the presence of as many as 21chemical constituents, including 9 or 10 additional unidentified compounds8. However, the

toxicity was NOT known about any of the compounds, including MIC.

1.2 Explanation of Possible Causes.

Several causes have been proposed, two of which have been subjected extensive examination.Cause is the admission of water via a water cleaning process where an isolation valve existed butthe line had not been blanked off (the Water 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 anddeliberately admitted water. Cause 2 would have required intimate knowledge of piping aroundthe tank, where to physically make the correct connection, and the removal of a pressureindicator and then the re-attachment of piping fittings.

However, neither is a root cause. The root causes were management decisions:

-Decision to neglect a flare system in need of repair;

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

- Decision to remove coolant from the refrigeration system used to cool the MIC storage tank.

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

Inadequate emergency planning and community awareness;

Lack of awareness of the potential impact of MIC on the community by the people operating

the plant; lack of communication with community officials before and during the incident.


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Inadequate community planning, allowing a large population to live near a hazardousmanufacturing 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 the importanceof these considerations in the sitting and operation of facilities.

1.3 The Plant Layout -1984

The plant was backwards integrated from a formulation plant to a fully integrated chemical

plant in the late 1970s. Fig. 3 is a photograph looking North where the 3 MIC storage tankswere surrounded with earth for insulation (on the right side, or towards the East side of theplant layout). Fig. 4 shows a cross section of the storage tanks with piping provided forinternal cooling, MIC flow in and out, and attachment to the process vent system via a reliefvalve should the tanks be over pressurized. Finally, Fig. 5 shows the effluent treatmentsystem downstream of the relief valves, for treatment of any material that might be

discharged if the relief valve opened, either due to over pressurization of an MIC tank orbecause of a relief valve leak.


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2.History of UCC

Started in 1969 in Bhopal. Chemical-Phosgene, Monomethlyamine, Methyl Isocyanate (MIC) and the pesticide

Carbaryl, also known as Sevin. Taken over by DOW Chemicals in 2001. DOW refused Union Carbides Liabilities in Bhopal, India.

2.1 The site 20 years later

Our most astonishing discovery was the current condition of the Bhopal plant site. As oneapproaches, it looks like a jungle. Plants and trees have taken over. Tank 610, the tank that overpressured and released the MIC, was removed from its underground vault, and is now aboveground and totally surrounded by brush and overgrowth. Even more astonishing, sadly, bags of

chemicals have been left behind. For 20 years. Filter area where a water washing cycle wasunderway the night of the accident. We were able to identify the gate valve that fed the processvent header located above in the pipe rack. Its stem indicated full closure, although this providesno evidence of its condition more than 20 years earlier during the incident.

An identical storage tank to 610. Much of the piping is in place, undisturbed after 20 years. Therupture disk tag is still readable, and somewhat hidden, the spring relief valve that leads to therelief vent system lines. In studying the piping up close, we conclude that it is quitesophisticated. If sabotage was committed, the person who did it had to have intimate knowledgeof piping into and out of the tank. Further, they had to have identified exactly how to remove a

pressure indicator, and attached a quick disconnect hose connection, then after the event removethis quick disconnect hose connection (the condition it was reported to have been found by aneye witness). Manufactured of stainless steel, it is in reasonably good condition after more than20 years. This plant had state-of-the-art equipment in place. Some motors appear as if they couldoperate today; simply flip the switch. Pumps, however, do show signs of corrosion after sitting inthe elements for 20 years. This flare system went out.


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Service several weeks earlier due to a corroded pipe replacement project . Little priority wasplaced on repairing it because the plant at the time was not manufacturing MIC. Much of thepaper that litters the floor are the remains of operating instructions and safe work permits.

Such surface pollution is thought to have contaminated groundwater and rendered the drinkingwater in Bhopal hazardous. It is important for us to learn that when environmental activists speak

of the deaths caused by the Bhopal Plant, they regard the MIC release as minor relative to thelong-term environmental effects.


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2.2 Pesticide Preparation

CHEMISTRY OF SEVIN-

Phosgene + Monomethylamine

Methyl Iso Cynate (MIC)

MIC + Alfa Naphthol

SEVIN

MIC is temperature sensitive & explosive at higher temperature.

MIC is highly reactive with water & iron.MIC damages respiratory system instantaneouslyMIC burns off skins cells on contact.

MIC PHYSICAL& CHEMICAL CHARACTERISTICS.

Methyl Isocyanate (C2H3NO) Liquid form Volatile Colourless

Strong, sharp odour Flash Point-7oC Molecular weight: 57.05 Daltons Boiling point (760 mm Hg): 102F (39.1C) Freezing point: -49F Vapour pressure: 348 mm Hg at 68F (20C) Vapour density: 1.42 (air = 1.00) Water solubility: Reactive 6.7% at 68F (20C) Flammability: Highly flammable

Content of gases

Methyl isocyanide (MIC) reacts with water to formmono methylamine (MMA) and carbon dioxide (CO2)

Hydrogen cyanide (HCN) blocks the oxygenreceptors and is extremely toxic . Phosgene was used as a war gas during World War I

Carbon monoxide (CO) is toxicNitrogen oxides (NOx) causes lung injuries


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All gases were heavier than air and thus replacedOxygen.

2.3 Possible causes

Several causes have been proposed, two of which have been subjected extensive examination. Cause1 captioned is the admission of water via a water cleaning process where an isolation valve existedbut the line had not been blanked off (the Water Washing Theory). This isolation valve was located

about 300 m from the storage tanks via a pipeline. Substantial water (500 kg plus line volume) withsome head was required along with one other key valve leaking. Cause 2 was sabotage, deliberatelyconnecting a water hose to piping that directly entered into the storage tank and deliberately admittedwater. 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.

The UCIL plant manufactured Sevin, a Union Carbide trade name for a pesticide, whose activeingredient is 1-napthyl-N-methylcarbamate, or the generic name carbaryl. The reaction involvedtwo reactants, methyl isocyanate (MIC) and alpha naphthol. Methyl isocyanate is reactive, toxic,volatile, and flammable. The maximum exposure (TLV-TWA) during an 8-hour period is 0.02ppm (20 parts per billion). By comparison, phosgene, another extremely toxic gas, has a TLV-TWA of 0.1 ppm (100 parts per billion). Individuals begin to experience severe irritation of thenose and throat at exposures to MIC above 21 ppm. The LC50 for rats exposed to MIC vapors inair for 4 hours is 5 ppm. In humans, exposure to high concentrations can cause enough fluid

accumulation in the lungs to cause drowning. At lower levels of exposure, the gas affects theeyes and lungs. It acts as a corrosive agent, eating away at moist vulnerable tissue, such asmucous membranes and eye surfaces. Long-term effects also exist. MIC has a boiling point of39.1oC and a vapor pressure of 348 mm Hg at 20oC. As such, it is quite volatile and it will easilyenter into the surroundings at very high concentrations. With a molecular weight of 57, about 2times that of air MIC has a higher vapor density compared to air.

The Disaster

9.00 PM Water cleaning of pipes start. 10.00 PM Water enters and reaction starts. 11.30 PM Gases coming out from the VGS-tower 00.30 AM The large siren sounds and is turned off. 00.50 AM The siren is heard within the plant area.


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Previous Warnings

1974 Contaminated well, cows died. 1978 Trade union wrote letter to managers and MP Government. 1978 Large fire. 1981-1984 Many leaks, workers injured,

also died.

3.IMPACT BHOPAL GAS DISASTER

SUFFERINGS-

- 2500 DEATHS IN 48 HOURS- 85000 AFFECTED- 5 Lac EXPOSEDi-PLANTS, ANIMALS INCLUDING FISHES.

Main symptoms:

Lacrimation and burning of eyes Breathlessness, cough & chest pain.

Respiratory Disorders

Irritation to the lungs, causing coughing and/or shortness of breathing. Higher exposurecaused build up of fluids (pulmonary oedema). Caused Asthma.

Cancer Hazard

Caused mutation (genetic changes). It caused cancer.


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Reproductive Hazard

Association between exposure to Methyl Isocyanate and miscarriages. It may damage thegrowing foetus. May also affect fertility in men and women.

Traces of many toxins were found in the Brest Milk of mothers and were in turntransmitted to the recipient babies.

Long Term Health Effects on Children

In 1989, the still-birth rate, the crude birth rate, the perinatal death rate, the neonataldeath rate and the infant mortality rate were still high in severely affected areas.

Higher incidence of psychiatric illnesses, febrile illnesses, acute respiratory infections,gastro- intestinal infections, superficial infections of the skin, eyes and ears.

Intellectual impairment and epilepsy. Failure-to-grow, delay in gross motor and language sector development in children born a

considerable time after their mothers gas exposure

Data Collectors-

TISS Mumbai. Indian Council of Medical Research (ICMR). Centre for Rehabilitation Studies (CRS). India Toxicology Research Centre (ITRC). Defense Research Development Organ (DRDO). Indian Council of Agricultural Research (ICAR). National Environment Engine Research Institute(NEERI). Council for Scientific and Industrial Research (CSIR).


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4. PREPARATION AND MITIGATION

PROCESS SAFETY MANAGEMENT.

Process Safety Information Reactivity Hazards Analysis SOPs & SMPs Equipment Reliability Safety System & Worker Training Emergency


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Compliance Audit & Statutory RegulationsEMERGENCY MANAGEMENT PLAN

1.

Process Safety Management2. Communication Network3. Fire Fighting Squad4. Emergency Medical Services5. Security / Law & Order6. Evacuation / Transportation7. Mock Drill & Simulation Exercise8. Community Awareness9. Rehabilitation Facility10.Adequate & Timely Media Release.

5. RESPONSE AND RELIEF

The company stresses the "immediate action" taken after the disaster and their continued

commitment to helping the victims. On December 4, the day following the leak, Union Carbide

sent material aid and several international medical experts to assist the medical facilities in

Bhopal.

Union Carbide states on its website that it put $2 million into the Indian Prime Minister's

immediate disaster relief fund on 11 December 1984. The corporation established the

Employees' Bhopal Relief Fund in February 1985, which raised more than $5 million for

immediate relief.

According to Union Carbide, in August 1987, they made an additional $4.6 million in

humanitarian interim relief available.

Union Carbide states that it also undertook several steps to provide continuing aid to the victims

of the Bhopal disaster after the court ruling, including.

The sale of its 50.9 percent interest in UCIL in April 1992 and establishment of acharitable trust to contribute to the building of a local hospital. The sale was finalized in

November 1994. The hospital was begun in October 1995 and was opened in 2001. The

company provided a fund with around $90 million from sale of its UCIL stock. In 1991,

the trust had amounted approximately $100 million. The hospital caters for the treatment

of heart, lung and eye problems.


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Providing "a $2.2 million grant to Arizona State University to establish a vocational-technical center in Bhopal, which was constructed and opened, but was later closed and

leveled by the government"

Donating $5 million to IRS. Developing the Response system with other members of the chemical industry as a

response to the Bhopal crisis, which is designed to help prevent such an event in the

future by improving community awareness, emergency preparedness and process safety

standards?

FUTURE PROSPECTIVE

The Bhopal gas tragedy is undoubtedly one of the worst industrial disasters in the historyof mankind. The incident triggered interest from industry, academia, and legislature, andis widely acknowledged as one of the defining events in the history of process safety.India has been experiencing rapid industrialization with gross domestic product (GDP)per capita going up to US$ 2900 in 2004 and the economy continues to grow at over 78% every year. Rapid industrial growth has contributed immensely to the economicgrowth but there has been significant cost in the form of environmental degradation andincreased public health risks. Increasing awareness of potential exposures to exogenousnon-biological agents arising out of human activity will become an important issue forthis century.

These exposures and their consequences generate many questions like health safety,safety of progeny, issues on compensation and punishments and so on. Althoughaccidents involving MIC or an accident of similar magnitude may or may not recur, butfor a country like ours which is fraught with human, environmental and economicalperils, dissecting out the long standing effects of the disaster will be of immense valueand significance while encountering future chemical disasters.

Although there has been an international consensus on the fact that the nature, severity ofdamage and sufferings in the survivors of the accident are of superlative order, attemptsat understanding the persistence of long standing effects are lagging from both academiaand industry. The study of human aspect of the tragedy had perhaps lagged behind andthere has been lack in strategic planning to institutionalize.

Studies on the long-term health consequences of the tragedy. Investigations conducted sofar have also raised a new question of for how long the gas victims would continue tosuffer from multi system disorders and whether their forthcoming generations would alsobe affected by these abnormalities.

In-depth molecular studies of ocular, respiratory, reproductive, immunological, geneticand psychological health must be continued if we wish to understand the extent andseverity of long term effects associated with the disaster. To cover up the inadequacies in


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medical care, the authors strongly suggest the necessity for long-term monitoring of theaffected community. and use of appropriate methods of investigation that include well-designed cohort studies for such conditions, characterization of personal exposure andaccident analysis to determine the possible components of toxic cloud as the investigators

have noted several clinical and epidemiological inadequacies, including poor studydesign, bias and inaccurate exposure classification. Studies aimed at understandingincreasing morbidity of MIC exposure carried out on cultured cellular model systems willprovide a framework of understanding the potential mechanism of toxicity of a host ofother exposures.

And may also uncover unique abnormalities in the survivors thereby stimulating effortsto design newer and more effective diagnostic and therapeutic strategies for helping thesurvivors.

While it is most unfortunate that the accident has occurred, this has opened up animmense opportunity to learn about adverse effects of MIC. In fact, the ramifications of

such findings would aid in shaping strategies for preventive management of futureindustrial disasters and refining risks that mankind faces from chemicals and otherenvironmental hazards.

Discussion

The Bhopal disaster began long before the actual event, and its effects continue today, twenty-one years later. Although many of the early investigation efforts were directed to the initiatingeventimproper line blinding during filter washing, or intentional contamination by attachmentof a water hoseit is clear today that the initiating event is basically irrelevant.

Clues to this accident were available in the days and months before it happened, and from the

perspective of our experience twenty-one years later, perhaps even years before. If even one ofthe basic protections, i.e. the refrigeration system, the scrubber, the flare, the pressure gauge, thewater curtain, and community emergency procedures, had been in place and functioningproperly, many, many lives could have been saved. If communications between the plant andcorporate management had been strongerand perhaps given the state of communicationtechnology in 1984, communications were as strong as they could have been local managementmay have had better information and support and therefore not have made flawed decisionsabout fundamental safety principles. Likewise, corporate management would have had theopportunity to hasten the already-planned shutdown of the plant.

Roots of this accident extend even further back, well before the involvement of Union Carbides

manufacturing and safety personnel. Optimistic market-size expectations led to an oversizedplant and therefore MIC storage capacity oversized by a factor of three. Failure of state andlocal government to control the shantytown growth near the plant meant a considerably largerimpacted population unable to shelter in place.

The consequences of Bhopal extend well beyond December 3, 1984 and the days immediatelyfollowing. Thousands of people injured that day continue to suffer from symptoms caused byexposure to MIC, including respiratory distress. And, because Union Carbide was banished soabruptly from the site, the chemicals remaining on site were never properly removed, leading to


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significant environmental and health impacts, including a large number of stillbirths, whichcontinue to this day.

Union Carbide paid an unprecedented large settlement to the Indian government and sufferedother significant business and market losses in the years following 1984. Forced to sell of

business after business in order to maintain its core operation, Union Carbide was eventuallysold to The Dow Chemical Company in 1999, marking the sad end of a chemical industrypioneer.

Serious accidents are not common, so it is easy to fall into the mindset that they cannot happen.This is a common human failing, and it explains many risky behaviors from driving too fast onthe highway to failure to maintain critical safety systems in a chemical plant. Bhopal clearlydisproves this. In no circumstances does unlikely mean impossible, and some possibleconsequences are clearly so significant that unlikely still leaves one with unacceptable risk that

must be addressed more aggressively.

If there is a silver lining to this dark cloud, Bhopal has lead to improved process safety practices,

through leading companies, through AIChEs Safety and Health Division and Center forChemical Process Safety, and through many other organizations around the world. Fundamental

principles such as Management of Change, Mechanical Integrity, Hazard Analysis, and Layers of

Protection are now in the toolbox of most practicing chemical engineers around the world. It

would be a stretch to say that an accident like Bhopal could never happen today, but as we work

6. 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.


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4. All the disasters that occurred in developed countries were neither due to the managerialoperations nor due to the safety regulations. However these were the biggest componentin the Bhopal gas tragedy as the management gave only lip service to process andpersonnel safety and the governments did not ensure compliance with the regulations.

5. There is a need for the improvements in method of safety. New legislation, stricterenforcement and personnel training should be in place.

6. Elementary R&D is needed in the causes of accidents and in industrialized processesused in the chemical process industries.

7. All the stakeholders need to play their part in building a safety culture.8. The effects on health caused by the leakage should have been mitigated if the medical,

social, and economic rehabilitation had been adequate.

7. REFERENCE

1. P. Shrivastava, Bhopal: Anatomy of a Crisis (2nd Ed.), Paul Chapman Publishing Ltd,London, UK 1992. T. R. Chouhan and others, Bhopal: the inside Story, The Apex Press,New York, NY 2005.

2. Bhopal Information Center, http://www.bhopal.com/, Accessed 30 Dec 2005 .3. Bhopal Gas Tragedy Relief and Rehabilitation Department, Bhopal, Government of

Madhya Pradesh.

4. J.P.Gupta, Ed., "Selected Papers Presented at the International Conference on Bhopal GasTragedy and its Effects on Process Safety," J. Loss Prevention, Vol 18, 2005, pp. 195-558.

report on bhipal gas disaster

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