Case study on Major Chemical Disasters-

Case study on Major Chemical Disasters-One day Symposium on “Prevention of Industrial/Chemical Disasters at Bangaloru

Accidents in Chemical process industries constitute major threat to property and population because of the magnitude. With the rapid development in science and technology, several new innovations have come up and Chemical process industries deal with thousands of new chemicals and several processes. Nevertheless, there are innumerable causes that lead to disasters of major or minor in nature. So it would be of great use if we could collate and categorize all the disasters, which occurred in the past, so that the analysis results of these disasters are not only a useful lesson but also is helpful to prevent their recurrence.

Disaster is an accident / event that can lead to tremendous destruction to the environment, equipment, plant and people. The consequences of the chemical disaster in the chemical toxic gas release and dispersion. The various accidents due to these consequences are well known and gives prominent caution to prepare, practice and amend the / Toxic Disaster Management plans for each and every hazardous process industries and their material storage / Handling location. As per amended factory act in 1985 after Bhopal incidents. Each chemical industry aims to achieve totally zero accidents potential. Therefore prevention, protection and suppression techniques have been applied to reduce the probability disaster.

Some of the worst disasters of toxic releases have occurred in toxic chemicals like MIC, Ammonia, and Chlorine cyclohexane etc. Some data’s on past planning in details which explains the various stages of Disaster Management plan. The various stages of Disaster Management are, Planning, Prevention, Preparedness, Response and Recovery.

We learn best through our own experiences in different phases of our life. Mistakes could be catastrophic in a chemical plant, but it is a great opportunity to learn and design a safer plant in the future. We must learn from previous incidents and develop design a safer plant in the future. We must learn from previous incidents and develop new procedures, practices and management systems.

These incidents have much learning which reveal many hidden facts about safety and provide efficient tools for prevention of similar incidents in the future. In spite of these lessons Indian industry continues to suffer.

  Let us take up the case of major disasters that had happened in our country. Ammomia & Chlorine are the toxic gases used in our industries, by many fertilizer plant and water treatment, chlore alkali plants bleaching in paper industries

Let us take up the toxic gas release of Ammonia & Chlorine resulted in Fatal accidents.

BHOPAL TRAGEDY

If we see the history of worst chemical disasters, in industries the first thing that comes to our memory is one at Bhopal

On the night of Dec. 2nd and 3rd, 1984, a Union Carbide plant in Bhopal, began leaking. due to run-away reactions, temperature and pressure rise and the safety valve lifted to the atmosphere. About 25-27 tons of the deadly gas methyl isocyanate spread through the city of Bhopal.

Half a million people were exposed to the gas. Protective systems that should have prevented or minimized discharge were out of service. Refrigeration system to cool the reactor was down. Scrubbing system to absorb the released vapour was not immediately available. Flare system to burn vapours getting past the scrubber was out of service.

Lessons we learned form Bhopal Tragedy

1)Reduce inventory of hazardous material (MIC)

2)Keep all the safety related equipment in order

3)Keep residential areas away from the plant

4) Proper Management

Another worst chemical disaster: that comes to our mind was;

 Flixborough Disaster – A CASE SYUDY.

On 1^st June 1974 the Nypro (UK) site at Flixborough was severely damaged by a large explosion. Twenty-eight workers were killed and a further 36 suffered injuries. Offsite consequences resulted in fifty-three reported injuries. Property in the surrounding area was damaged to a varying degree.

A 20 inch bypass system ruptured, which may have been caused by a fire on a nearby 8 inch pipe. This resulted in the escape of a large quantity of cyclohexane. The cyclohexane formed a flammable mixture and subsequently found a source of ignition. At about 16:53 hours there was a massive vapour cloud explosion, which caused extensive damage and started numerous fires on the site.

Eighteen fatalities occurred in the control room as a result of the windows shattering and the collapse of the roof. No one escaped from the control room.

 The fires burned for several days and after ten days those that still raged were hampering the rescue work.

 CASE STUDY 1

Mangalore Chemicals and Fertilizers Limited

There was a chemical accident in the Urea Plant at M/s. Mangalore Chemicals and Fertilizers Limited, Panambur, Mangalore on 9.2.2000. An 8" dia high-pressure pipeline housing a weldolet was connected between autoclave (urea reactor) of 108MT capacity and the stripper to carry ammonium carbamate (Urea Solution). The pressure of pipe line was of the order of 141kg/cm2 and the temperature of 180 C. The Solution had contained 29% of ammonia, 18% carbon di oxide and 32% of urea..

On 9^th February 2000, a substantial quantity of ammonium carbamate solution leakage was noticed at the weldolet joint of the pipeline. A maintenance manager along with two operators, an engineer and two contract workmen were trying to plug the leakage by providing a proper clamping. In the process, the weldolet joint gave way resulting in sudden release of pressurized hot ammonium carbamate solution. As a result, the personnel on the job were exposed to hot solution and toxic gas. Consequent to which, 8 persons were affected amongst them 2 died on the spot and the other two at the hospital amounting to death of 4 persons including the maintenance manager and an engineer.

Investigation conducted by the department under the guidance of an expert committee revealed that the weldolet used in the high pressure pipe line had high carbon content which is not suggested for that kind of a process, maintenance Repair works was undertaken on line even after noticing the hazardous solution which amounts of non implementation of shutting down procedures. Further the high-pressure pipeline was not subjected to hydrostatic test, ultrasonic tests and examinations as required under relevant provisions of law for its soundness. The personnel who were on the job were not wearing any personal protective equipment in addition to non-adherence to work to permit system.

The expert committee investigated made the following recommendations to prevent any incident in future.

The pipeline, connected equipment and the accessories must be subjected to hydrostatic test as required under the relevant provision of law;

Weldolet must be subjected to 100% examination to detect corrosion and the soundness;

Maintenance/repair works shall not be undertaken on line, it shall be done only as per standard maintenance procedure drawn up before hand;

Permit to work system shall be strictly adhered to along with suitable personal protective equipment;

The on site emergency plan rehearsals shall be put to rigorous tests and practiced by updating the weaknesses noticed from time to time;

The personnel including the contract workmen shall be put to rigorous training in handling chemical emergencies particularly to bring a change in their attitudinal behaviour of over confidence;

  CASE STUDY 2

National Fertilisers Limited (NFL) at Panipat.

The Panipat tragedy: what went wrong?

Liquid ammonia burst out at the high pressure of 23 kg per sq cm, vaporising within seconds to form suffocating clouds of deadly gas. This hit and choked to death eleven persons and injured ten even as their colleagues sprung into action to diffuse the gas with water sprays.

Liquid ammonia hit workers Coughing and choking, with lungs bursting, scrambled for fresh air.

It is a Freak accident? This was the first major incident in any of the NFL plants. When working on the ammonia pipelines. It was admitted to down to earth that for such work "Need to take extra precautions to ensure that workers other than those doing the hazardous task, are not present in the vicinity,"

 

CASE STUDY 3

The Chlorine Gas Leak at Jamshedpur

People of Jamshedpur were caught unaware when they were exposed to a dense, pale green, pungent and poisonous gas, Chlorine. This gas had leaked from an unused cylinder lying in the Tata Motor’s water treatment plant for the past 10 years. By the next day, around 150 to 200 people had been hospitalised. The affected people also included company employees and their family members. So far no deaths have been reported. Later, in a statement, Tata Motors claimed that the chlorine leak has been plugged and about 60 to 70 residents who reported breathing difficulty were admitted to the Tata Motors hospital in Jamshedpur. The Chief Minister of Jharkahnd, Madhu Koda, alleged that negligence by Tata Motors had led to the leakage of chlorine gas.

.As we know Chlorine gas has strong oxidising properties. Its toxicity irritates the respiratory system. Severe exposure to the gas may cause pulmonary edema within 30 to 60 minutes and die´. There is no available prophylactic or post exposure therapy for chlorine.

CASE STUDY 4

SPIC ammonia unit shut due to leakage problem

Southern Petrochemical Industries Corporation (SPIC) at Tuticorin has been shut down due to a leakage in the pipeline. When the repair works were going on, a fatal accident occurred on October 1, company sources told Business Line.

Sources said that after the southern grid failure last month, technical problems arose in SPIC's plant, causing a leakage in the pipeline. The plant has been shut down since September 27.

While trying to do the repair work, Mr Thiraviyaraj, Joint Manager (Operations) slipped and fell. The gas mask he was wearing came off and he died of asphyxiation, it is learnt.

It is understood that it would take at least another 10 days to restart the plant.

None of the senior officials of the company was available for comment, and therefore, no estimate of the value of loss in production is readily available.

Only last year, the Tuticorin plant of SPIC had been shut down between May 1 and June 22 for a "routine turnaround maintenance", which caused a loss of production of 1.03 lakh tonnes of urea.

CONCLUSIONS

We learn best through our own experiences in different phases of our life.

Mistakes could be catastrophic in a chemical plant, but it is a great opportunity to learn and design a safer plant in the future.

We must learn from previous incidents and develop new procedures, practices and management systems.

These incidents have much learning which reveal many hidden facts about safety and provide efficient tools for prevention of similar incidents in the future.

MAJOR CHEMICAL DISASTERS IN INDIA

Origin of accident	Year	Date	Location	Products involved	Number of
					Deaths	Injured	Evacuated
Explosion (warehouse)	1992	29.04	New Delhi	Chemicals	43	20
Fire at a chemical store	1994	13.11	New Delhi	Toxiccloud (chemicals)		500
Leakage	1984	03.12	Bhopal*	Methyl isocyanate	2800	50 000	200 000
Leakage	1989	05.05	Britannia Chowk	Chlorine	-	200	..
Leakage	1989	17.01	Bhatinda	Ammonia	-	500	..
Leakage	1987	24.06	Bhopal	Ammonia			200 000
leakage (transport accident)	1997	21.01	Bhopal	Ammonia		400
Leakage from a pipeline	1991	00.12	Calcutta	Chlorine.		200
Leakage in an Ice Factory	1990	00.07	Lucknow	Ammonia gas		200
Release	1985	14.05	Cochin	Hexacyclo-pentadiene	-	200	..
Transport accident	1994	00.01	Thane District	Chlorine gas	4	298
Transport accident	1991	00.01	New Bombay	Ammonia gas	1	150
Transport accident	1995	00.12	Maharashtra	Ammonia gas		2 000
	1985		India	Chlorine	1	150	-