RISKS OF CHLORINE IN DCM PLANT, NEW DELHI

Prof.T.Shivaji Rao,

Director, Centre for Environmental Studies,

GITAM University, 

Visakhapatnam-530045

 

 

CIVIL ORIGINAL JURISDICTION

 

CIVIL WRIT PETITION NO. 12739 OF 1985

 

M.C.Mehta                                                                            … Petitioner

                                                            Versus

Union of India & Ors                                                 … Respondents.

 

AFFIDAVIT

 

I, M.C.Mehta, S/o Shri.Tirth Ram Mehta, R.o 3, Ring Road, Laj at Nagar-IV, New Delhi, do hereby affirm and declare as under:-

 

  1. That I am petitioner-in-person in above said case.
  2. That as per the direction of this Hon’ble Court, I am enclosing herewith a report of three experts (Annexure-I)  who visited Chlorine Unit of M/s Shriram Foods and Fertilizers Ltd., Najafgarh, New Delhi on 9th December, 1985......................

 

 

Report On The Chlorine Unit Of M/S.Shriram Food And Fertilizers Industries Ltd., New Delhi

 

PREFACE

 

Annexure-I

 

As per the orders of the Supreme Court, and a request made by Shri.M.C.Mehta, the petitioner in Writ Petition No.12739 of 1985, we, the following members, namely,

1.Prof.t.Shivaji Rao

2. Dr.G.D.Agarwal

3. Mr.Prabir Purkaystha

Accompanied by Shri.M.C.Mehta have visited M/s Shriram Food and Fertilisers Industries Ltd. (Chlorine Unit), on Monday, the 9th December, 1985.  The report of our visit including our analysis of the hazards to the people is presented here.

 

 

I.                   INTRODUCTION

 

Thousands of tonnes of hazardous chemical substances are daily produced, transported, stored and used by industries in many countries. Some of these chemicals are highly toxic to human beings and their environment and the accidental release of even small amounts of such toxic substances into the atmosphere of a highly densely populated residential area or the working environment of industrial labour is bound to cause extremely serious consequences to public health and welfare.  It would have been very ideal both for human environment and industrial economy, if such hazardous chemical accidents did not happen at all.

Unfortunately most of the accidents  arise because something unforeseen occurs for which existing safety devices and procedures have not been designed.  Apart from the uncertainty, one has to deal, therefore, with the management of surprise which are definition unpredictable.  People may be exposed to toxic chemicals by an accidental release through an explosion in a factory for reasons like fire accidents, equipment failure or sabotage.  Accidents are going to happen regardless of our efforts to prevent them.

Even when the most ideal emergency-response system is devised and alarm sirens given to alert the public of an impending chemical accidents, and instant evacuation of people is contemplated, the wind-speeds and directions may change so suddenly during the period that the disastrous consequences may be fall population at the most unexpected sports in the neighbourhood of the industry.

Having realized the inherent inadequacies in running the industries without spillover of toxic chemicals into residential areas, the USSR Government have shifted many industries from Moscow and they have made laws to provide protective health zones of 1km. distance around hazardous industries.   Moreover they have provided green-belts of about 10km width in between industrial belts and residential areas in cities like Stalingrad and Perth (Australia).

A good look at the worst of all possible events could make a lot of differed between a disaster and our ability to anticipate such potential hazards and take timely preventive action by taking lessons from past experiences in industrial accidents relating to toxic chemicals as this comparatively new threat of gas leaks is growing day-by-day. Moreover, the toxic chemicals may affect not only the industrial workers, but also the general public by any one or more combination of routes, such as the air we breathe, the food we eat, the water we drink and the whole range of influences and materials in our living environment, producing a range of known or suspected health problems including carcinogenic, mutagenic and teratogenic effects on the present and future generations.

No two chemical accidents need be exactly the same because, by definition, an accident is an unplanned event.  In particular, the environmental impact of an accident involving the sudden release of a toxic chemical due to an exploded tank or a ruptured pipeline is different from that of a normal emergency resulting from a traffic accident, fire or train derailment.    Even though the vulnerable points are identified, adequate preventive and safety measures adopted and emergency-response plans are chalked-out and practiced, there remains the distinct possibility that an accident may occur at a place originally considered safe and it will trigger off a chain reaction whose potential impact including its multiplier effects on the production, distribution and storage of hazardous chemicals in the factory cannot be imagined and hence, our industrial managements must make continuous evaluation of their plants not only for replacement of inefficient and obsolete plant and machinery, but also for relocation of their most hazardous components in the light of their expansion programmes and potentially harmful effects on the growth of population in the industrial neighbourhoods.

II. OBSERVATIONS

 

Having gone through Manmohan Singh Committee Report (hereinafter called the Singh Report), the report of Dr.Slater and other documents and also after a visit to chlorine plant of M/s. Shriram Food Fertiliser Industry (SFFI), Najafgarh, the committee makes the following observations.

Comments on the chlorine plant:

The SFFI stores chlorine in three process tanks of 20MT each and one tank of 25MT.  It has been stated that the use of two tanks of 100MT capacity has been discontinued as per the recommendations of the Singh Committee.  It has also been stated that the danger to the public has been “minimized” after the discontinuance of the 100MT tanks.  The danger which still exists to the population of North, West and Central Delhi will be discussed in quantitative terms below.

  1. Concentration of chlorine in the air above 25 parts per million (PPM) is defined by occupational safety and Health Authorities (OSHA), USA as Immediately Dangerous to Life and Health (IDLH).  The IDLH level for Methyl Isocyanate (MIC) is 20 PPM as per OSHA.  It may also be noted that chlorine was extensively used in the First World War as a poison gas. 
  2. The impact of accidental release of chlorine from the industries on the adjoining area and population based on Standard Texts on Atmospheric Dispersion is presented as follows:

Table: Possible Short-term Peak Concentrations of chlorine (PPM) at different points under different wind speeds for a release of 5kg Chlorine/Sec (18 MT  in one hour)

 

Distance from source km

Natural Wind Stability

Extremely Stable Atmosphere

V=0.5

V=1.0

V=2.0

V=0.5

V=1.0

V=2.0

0.5

1636

818

409

5920

2960

1480

1.0

472

236

118

2226

1113

556

3.0

86

43

22

432

216

108

5.0

38

19

10

262

131

66

8.0

20

10

5

110

55

28

 

Note:  i) Hazardous Level of Chlorine: 25 PPM (Immediately dangerous to life

               and health

                        ii) Instant Death Level of Chlorine: 1000PPM

As per the chlorine dispersion data of Singh Committee, if at any time the chlorine leakage takes place from the storage tanks, the effect on the surrounding community will be disastrous as the lethal dose is 1000 PPM and ‘FEW INHALATIONS CAN PROVE FATA’ (Page 47 of Singh Committee Report) It may be noted that the dispersion shown above is for the failure of the 20/25 MT tanks which have been allowed to be continued by the Singh Committee report or from pipe/valve rupture. 

  1. Storage tank failure could occur in the following way:

a)      Rupturing of the tank due to corrosion or stress induced failure.

b)      Rupturing of valves and piping connected to the tank.

c)      Fire in the area.

d)      Enemy action, sabotage etc.

Any one of the above causes could lead to accidental release of 20 to 25 MT.  The instantaneous release of chlorine vapour on the tank and vapourisation of the liquid chlorine, as chlorine has boiling point -34oC.  The rate of chlorine release can be higher than that shown in the calculations of  20/25 MT release per hour.

  1. SFFI uses a method of spraying water and foam, on to liquid chlorine to neutralie spillage.  They also have a dyke to contain the liquid chlorine.  While this may have same effect if chlorine spillage is small, it will result in even more rapid vapourisation of chlorine in view of the exotheric reaction of chlorine and water.   To quote from the Slater Report “the principle behind the design of the water deluge needs to be re-examined and some modeling performed to establish under what conditions, if any, it can help and the critical leak size above which it would exacerbate the consequences to the public by increasing the ‘boil-off rate’ (Slater Report P.3)
  2. Three of the 20 MT tanks are of 1949 vintage- they are 37 years old.  The other 25 MT tank is also 21 years old.  Without radiography and thickness survey of the above tanks, the safety margins of the tanks are not known.  In view of the general level of maintenance SFFI as exemplified by the Oleum tank collapse, legitimate doubts exist regarding the safety in this facility.
  3. The danger to the population is directly proportional to the amount of chlorine stored in the container tanks.  If 20 tonnes are stored in ½ tonne container, then the risk is less, as the failure of any container will release only half a tonne.  If one 20/25 MT capacity tank is used, its failure releases 20/25 MT and thereby raises the concentration level of chlorine above the danger point for large sections of the people.  The danger in SFFI lies in the size of the storage.  Further, at any point, a number of cylinders are in the filling area, and this could be hazard in case of fire etc.
  4. The Manmohan Singh Committee had recommended that these 100MT tanks should not be used for storage (P.53).  However, we understand that these tanks were used for storage till recently.  There is no guarantee that even if designed as surge tanks, these may still not be used to store chlorine.
  5. The SFFI has a scrubbing system of  MAXIMUM CAPACITY OF ONLY 4 MT /HR.  While the maximum storage capacity was              as large as 285 MT even the reduced storage of 60 to 85 MT allowed by the Singh Committee is far above the neutralizing capacity.  Indeed the Singh Report states that, the scrubber system has ‘so far been used for neutralization upto 1.5 tonnes/hr’ only (P.8) In case an emergency like failure of tank, fire etc. takes place, the neutralsiation system cannot be used effectively to control the situation.
  6. A number of deficiencies exist with the scrubbing system. As the Singh Report makes clear (PP.37-38), the scrubber neutralizing system is designed for normal venting only and not for emergency discharges which would involve much larger gas flows.  This is similar to the situation which obtained at Bhopal where due to fundamental inadequacy of the neutralizing system designed for normal discharges only, massive quantities of toxic gases escaped into the atmosphere.  The result of such design practice is clear now to everybody. It is surprising that even after a disaster of such magnitude at Bhopal, this plant should be allowed to operate with such a small capacity of neutralizing system.
  7. A number of studies have shown that scrubbers designed for small leakages are not able to handle high discharges for the following reasons:

a)      Two phase flow i.e. mixture of liquid and gas in case of major accidents.  The scrubber designed for small leaks gets overwhelmed in such  conditions.

b)      Pressure of discharge is much higher than the pump head leading to non-flow of the scrubbing solution.

  1. Though the Singh Committee had suggested the modification f the scrubbing system, the committee observed that only inadequate marginal modifications have been made.  The MAJOR TECHNICAL PARAMETERS OF THE SCRUBBER REMAIN THE SAME, NAMELY LOW NEUTRALISATION CAPACITY.
  2. Apart from the scrubber, there does not seem to be any major safety system in the plant.  There are no provisions for water curtains or other arrangements to knock down the gas cloud or vapour.
  3. If any leakage develops in the chlorine storage tanks, the contents of the tank can only be transferred by siphoning action and not by pumping.  Rapid evacuation of a leaking tank is not possible under such conditions (pp 24-25 of Singh Report)
  4. Continuous measurement of moisture in the tanks is a must in view of the danger of wet chlorine corroding the tanks.  Currently intermittent sampling is  used to keep track of the moisture content.
  5. The filling system of the 20/25 MT tanks is manual with a temperature switch as an indication of the prescribed level being crossed.  No direct indications exist for overfilling which could lead to a hazard.
  6.   Long piping systems with a number of joints pose an environmental hazard as undetected leaks can continue for long  periods.   Even during the plant  visit on 9-12-1985 chlorine leakage was noticed from a flanged joint.
  7. SFFI has not so far implemented the recommendations of Singh Committee in respect of

a)      constructing a shed over cylinder store area,

b)      installing load cells and carrying out radiography of chlorine storage tanks,

c)      modifications to control room

d)      maintaining adequate pressure in fire-fighting systems and

e)      provision of under-ground pit etc. etc.

As can be seen from the above, the plant is totally unsafe on the following counts:-

a)        STORAGE OF LARGE VOLUMES OF CHLORINE UNDER PRESSURE.

b)        UNDERSIZED NEUTRALISATIONSYSTEMS

c)        PROXIMITY TO POPULATION CENTRES OF HIGH DENSITY

d)        UNSAFE WORKING CONDITIONS AND PREVIOUS ACCIDENTS IN SFFI AS SEEN BY THE MASSIVE OLEUM LEAKAGE ON DECEMBER FOURTH.

 

III. DISCUSSIONS

 

Under the circumstances, it is pertinent to review the question of protection of public health and safety in the context of the crucial location of the industry and its potential for chemical accidents.

Question: Can a facility such as the chlorine-section of SFFI (providing around 120tpdof dry chlorine gas, liquefying it, supplying some 70 tpd to HIL converting a part of it into Hcl and another part into bleaching powder and filling 20-30 tpd in standard one tonne cylinders for sale to sundry customers) ever be made entirely safe for the community living around it (such as that living around SFFI)?

Answer: No, the reasoning being as follows:

a)      Toxicity:  The extremely high toxicity of chlorine needs no elaboration.  It was invented as a war gas.

b)      Storage: The greatest hazard is posed from large storage since they are under high pressure and often at low temperatures and any failure or significant leak results in release of large quantities within a short period.  SFFI has 2 bullets of 100 MT capacity each and 5 of 20/25 MT capacity each on location, one stated to have been abandoned for some years.  The stress of Manmohan Singh Report and of other recent arguments has been to avoid (or discontinue, as they say) the use of the tanks for storage and use them only “dump” or surge” tanks.  We consider this infructuous and impractical since (i) In an industrial system like this production and consumption or utilization cannot be balanced most of the time and some balancing storage shall always be necessary.  Thus, what if HIL operates only one shift a day or wants their total requirement of the day within a few hours?  What if HIL stops functioning or there is a problem in pipe-line?  Or there is a problem in pipe-line? Or there is a problem in Hcl unit or bleaching powder unit?  Or if filled one-tonnersre not lifted due to bundh, a curfew or a transporter’s strike? There will always be a 101 reasons for imbalance and the surplus chlorine shallhave to be stored or “dumped” whatever one may call it.

ii)             The very presence of these costly tanks is a proof of their need and once they are there, they will be full sometimes if not all the time.  Experience indicates that in India all “Guard-ponds”, ‘buffer-tanks” etc. remain full all the time and generally, act as flow through units.  Miss Bali’s impression that often all chlorine tanks at SFFI were full may not be far from truth and to us not far from expectation.

iii)           Discontinuing the use of these tanks (2 Nos. 100MT capacity and 1 No.;20/25 MT cpacity) but retaining them as emergency “dump” tanks, as suggested in Manmohan Singh Committee Report shall lead to poor maintenance and loss of reliability of various systems on these tanks when an emergency really arises.

iv)           With the operational requirements of one tank receiving chlorine, one tank delivering chlorine, and the third under evacuation, an average of 20 MT and a frequent peak of 35-40 MT shall be in storage at any time in the 3 Nos. 20/25MT bullets if the Singh Committee recommendations were fully implemented.  To this may be added the 40-60 MT in one tonne in the filling yard.  Even 20 MT is enough to cause a disaster in the location of SFFI..  And as discussed, storage annot be reduced even to this level,leave apart lower levels.

c)      Pipe-lines, flanged-joints valves, pump-gaskets etc. The hazards due to a failure in these appears to have been under-estimated and under-stressed.  Maintaiing such long, complex and jumbled systems in a leak-proof condition is IMPOSSIBLE.  Some significant leaks are known to have taken placed and many more may have gave unnoticed.  Unfavourable meteorological conditions combined with a significant leakmay any day result in the death of some unsuspecting passers-by on a cold winter-night, or children walking to school at dawn.

d)      Safety devices and provisions: Most of thee are designed to protect healthy, knowledgeable and alert plant-workers against routine leaks and failures and shall rarely be effective in case of a significant failure or accident.  Provision of oxygen masks or medical facilities can be of little help to persons falling victims outside the premises.

e)      Meteorology :  Often notions like chlorine gas is heavier than air and so can be contained by a few meters of AC/GC sheet curtain probably do mere damage than good.  The density of chlorine is not much different than that of MIC, SO3 or SO2.  The formation f clouds with fine droplets of the liquid entrained in the gas evaporating from release of liquids stored under pressure (as at Bhopal or recently at Delhi)and being swept by winds horizontally with almost no vertical dispersion could have (or would have) happened, with chlorine too. The occurrence of low-level inversions (as low as 30-40 m above GL)in Northern India and its’ affects on transport has neither been properly studied nor is understood.  And one an never be too sure.

f)        The only safe solution::  Whether one takes the Dr.Slater Report or the Manmohan Singh Committee Report, the ultimate gist is, and so is going to be the consensus of all people having even a rudimentary knowledge of the subject that a facility, like SFFI cannot be made SAFE at its present location.  The only alternatives to being really SAFE are either relocate the factory with a minimum 10km green belt/buffer zone or to relocate the neighbouring communities to create such a green belt/buffer zone.

Question: At this stage one is likely to ask –Given a Unit like SFFI can never be made entirely SAFE for its present location in densely populated surroundings, can it be made atleast reasonably SAFE?  Will a complete compliance of  Singh Committee Report be not adequate for this?

Answer: No. The reasoning being as follows :-

i)        Reasonably safe for what conditions? For normal steady-state operation conditions- Yes. SFFI (Whether on itself or under Government and public pressure) has already rigged up a system for such normal steady-state conditions.  Singh Committee recommendations further help on it.  If need be opinion of more experts (people with real experience in handling toxic and hazardous chemicals) can be sought to improve the system further.  Even these improved facilities may not work under emergencies and upset conditions which are none too rare in India due to (i) frequent power tripplings (ii) extreme climate variations (iii) presence of all types and hues of extremists and anti-social elements all-around and most of all (iv) extremely poor equipment maintenance and credibility/reliability of operating personnel to act correctly on the spur of  the moment.  The last factor may be due to (a) stress and nervousness leading to confusion at moments of  crisis, (b) poor training (c ) lack of commitment, dedication and involvement (do poor working conditions or (d) any other factors.  But the fact is, that it is there and has been proved time and again by Bhopal, Delhi and Bombay gas leaks and even the frequent rail and road accidents.  In facilities like SFFI poor maintenance of equipment and operations performance accentuated by (i) extremely poor and ineffective inspection and enforcement by Government agencies like Inspector of Factories, Labour Inspector, Pollution Control Board etc. (ii) a plethora of non-specific and often confusing rules and regulations and (iii) extremely poor industrial relations.

 

IV.  CONCLUSION

 

Under so many uncertain factors, a chlorine manufacturing unit cannot be even reasonably safe when located in proximity to a densely populated area.  Under the circumstances, the only practical solution is to re-locate the chlorine plant of SFFI so as to be at last 10km away from the urban limits of densely populated areas, with adequate safety measures.

 

Sd/-                                          Sd/-                                           Sd-

Dr. G.D.Agarwal                    Prof.T.Shivaji Rao                      P.Purkaystha.

 

 

 

 

 

 

 

 

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