REPORT OF CASE
STUDIES IN THE STATE OF TAMIL NADU
Case Study on
Accidents I Dangerous Occurrence for the year 2002
1. In a fire works manufacturing factory, while one of the worker tried to cut the fuses with a Iron knife, sparks were generated and fell on the waste stored nearby and resulted 1n a fire accident. "Due to this accident, one worker died.
Causes:
1. Iron knives were used for fuse cutting
2. Wastes were stored in the fuse cutting area.
2. In a coal based power generation factory, the workers were removing the choke In the ash hopper. They opened the hopper gate and found a very huge block in it and hence started hitting the block with a iron rod. Suddently it gave way and the whole slag at a temperature of 250°C - 300°C stagnating above it started flowing and splashed over the body of the workers. One worker died and one worker received bum injuries.
Causes:
There was no provision to contain or hold the slag from splashing when the choke was removed
3. In a semi-mechanized safety matches manufacturing unit there was a frame filling cum dipping machine in the factory. Dipped splints (Match sticks) were received from this machine in a poly woven sack and weighed. This sack was then transferred to the dipped splints room manually. While a worker was dragging the bag and storing the above sack by the side of the wall in the Dipped Splints Racks (DSR) room he noticed sparks of fire from the sack. This fire spread to the other sacks containing the match sticks and it developed Into a major fire. This in turn within a short while spread to the adjacent box filling hall through the door. Due to this fire accident, 13 workers died and 41 workers received bum injury.
Causes:
Synthetic bag contained dipped splints was dragged on the floor. Floor friction ignited the match stick.
4. In a Match factory. in the Box Filling Section. filling the match sticks in the match box was carried out with the help of box filling machine. Around 20 workers were engaged in box filling section./\> ..,
Dipped splints which were kept In the Aluminium tray were filled in the empty match, boxes with the help of filling machine. While doing so, due to friction of match stick heads with the friction composition of the empty match boxes, Fire broke out and spread over the match sticks kept in the Aluminium tray and further the fire spread to the adjacent room where 300 trays of dried match sticks were stored. Due to this fire accident, 4 workers died and 14 workers received burn injured
Causes:
Due to friction between the head composition and the friction composition of the empty match boxes fire broke
out.
5. In a textile industry a worker was engaged In the work of
transferring the bobbins in a trolley from 2nd floor to 3rd floor. He kept the collapsible
gates of both the lift cage and the landing platform open. He was pushing a trolley
towards the lift. Meanwhile someone operated the lift to third floor. The
worker thinking that the lift ca~ was available went pushing the trolley
unwarily. As the lift cage was not available he plummeted into the hollow lift
way along with the trolley and grievously hit at the base of the lift pit after
traversing a depth of 33 ft resulting in his death.
Causes:
Interlocking the device that
will
prevent the lift cage from being operated unless both gates of the lift
cage and landing platform re In closed position was not fitted to the lift.
6. In
a Fertilizer manufacturing factory urea manufactured in prill tower passes
through a grizzly (a stainless steel selve) and falls on a conveyor. To
facilitate repairing works to be carried out to a grizzly bar, two mental rods
were placed above the grizzly bar and this was covered by a tarpaulin
sheet right below this arrangement welding of grizzly bar was carried out.
When the welding process was being carried out heavy lumps of urea
started falling down from the prill tower and fell on the iron plates placed over the grizzly bar. The iron plates
along with heavy lumps of urea fell on the workers working right below the
covered tarpaulin sheet and they sustained head Injuries and died.
Causes :
The temporary arrangements made above the grizzly bar to facilitate welding work was not of a strong and rigid construction to withstand falling of heavy lumps of urea from prill tower.
7. In a cement factory. the Coal Mill which was a horizontal,
rotary unit of 4 m. dial consisted of two chambers divided by a diaphragm the first chamber
Is called "Drying Chamber" and the second one was called the
"Grinding Chamber". The
accident took place in the Drying Chamber of the coal mill. Lumps of coal were
carried to
the Drying
chamber by the hot gas comprising of carbon dioxide, Nitrogen and Oxygen from
the pre-heater. Drying takes place as the coal mill rotates. As the maintenance
crew wanted to tighten the "felt packing" In the inlet seal ring of
the drying chamber, they tried to open the "seal ring" by unscrewing
the bolts. While doing so, some three bolts got jammed; hence a contract worker
(welder) and a company employee (Helper) were assigned the job of cutting the
jammed bolts by means of Oxy-Acetylene gas flame.
These two workers entered the inside of coal mill through the manhole
opening using a ladder and were then given the oxygen and Acetylene Cylinder hoses. The Cylinders were
kept outside the coal mill. At that time, two other contract workers were
already inside the coal mill and were working on the Diaphragm side of the chamber.
Actually these two contract workers were chiseling out the worn-out ball
sticking
to the holes in the diaphragm.
The welder and the Helper meanwhile started cutting the jammed bolt using Oxy
Acetylene Flame and finished cutting the first one. When they started cutting the second bolt, there was a big bang followed by a flash-fire. Flame and smoke came out of
the manhole. All the four
workers who were working inside the coal mill came rushing out of the coal mill
with burnt skin and fire injuries.
Inspite of
hospitalization and medical treatment, all the four victims died later due to burn injuries.
Causes :
1. In the drying chamber of the
coal mill,
there was a residual coal dust formed at the bottom. Due to the shuffling and
movement of the workers inside the coal mill, the dormant coal dust got
disturbed and started getting dispersed
inside. As soon as the Oxy Acetylene torch was lit for cutting the second bolt,
the coal dust got exploded followed by a flash of fire. The rapid release
of heat from the explosion
caused severe
burn injuries to the workers.
2. There was no "work permit system" followed in
the
factory .
1.
In a textile industry,
in the warping section, a worker tried to check the warp tension with his hand.
His hand had got caught in- between the warp yarns on the beam which was
rotating at a speed of about 1000 rpm. Because of the high speed rotation of
the beam he was pulled in and his body was caught in between the warp yarns
resulting in death of the worker.
Causes:
1. Pull cord, to the warping machine with limit switch arrangement was not provided.
2. Electronic sensor was not provided to the warping machine to sense and switch off the machine if anybody enters into the beaming zone of the warping machine.
2. In a match work factory, manual mixing of chemicals
like potassium chlorate, sulphur,
red manganese/black manganese. glass powder. potassium bi-chromate, rosin, Ammonia solution with water has been done
In a bucket made of iron.
While mixing the
chemicals with a wooden stick due to friction developed from the iron bucket a
spark emanated from the bucket and caught fire.
Suddenly the worker kicked the bucket thereby the fire got spread to the sticks of the chemical dipped match sticks, which were stacked in Gunny
bags. Due to this fire, huge smoke developed
and four woman workers rushed into the toilet and locked themselves up inside. Due to this accident 7
workers died and 9 workers were injured.
Causes:
Mixing was done in a container made of iron.
3. In
a foundry, worker was operating the die casting machine along with a
apprentice. The apprentice in an attempt to remove the component which has
fallen down in between the dies earlier, bent down and inserted his head
between the dies and the operator did not
notice this and operated the
die casting machine. The dies closed and the head of worker got crushed in between the dies
and the worked died.
Causes:
Doors covering the 2 dies (fixed and
movable) with an interlock arrangement which will prevent the machine from being
operated when the doors are open was not provided.
4.
A chemical factory. has erected three MS cylinderical storage vessels
with a
capacity of 24 KI. - 2 nos. and 30 KI. - 1 no. At the time of incident, a tanker lorry with 24 KI. petroleum product
was brought to the premises for the purpose of unloading into the
installed storage tanks.
The workers tried to unload the petroleum
product into the left extreme vessel of the 3 vessels (30 KI. capacity) by
using the rubber hose, one end of the rubber hose was connected to the out-let
valve of the lorry and the other end of the rubber hose was connected to the 30
KI. horizontal tank valve.
While transferring the material, there was
some leakage at the point of outlet valve connected to the rubber hose. In order to control the leakage, the workers
decided to move the lorry to correct position. The driver started the tanker
lorry and immediately there was a sudden fire noticed at the out let valve
leakage area. The workers tried to put out the fire but they could not do so.
Fire spread out to the other area and consequently the storage vessel got
suddenly burst out and thrown out from its foundation.
Because of this explosion, the petroleum material
became a
fire ball, causing minor burn
injury to about 23 on-Iookers and
nearby factory workers.
Causes :
1.
The petroleum
product which is very highly flammable in nature was unloaded from the road
tanker to the M.S. tanks without providing proper bonding to the road tanker
and the storage tank; also earthing to avoid the risk of static electricity was
not done.
2.
While the
petroleum product was leaking through the rubber hose, the driver started the tanker
lorry. The small sparks released from the exhaust pipe, ignited the petroleum
product vapour, resulting in fire and tank explosion.
5. In a Cement factory, lubrication oil pipeline of
vertical Roller Mill II of Raw
Meal Section was rinsed with kerosene using centrifugal circulating pump, to remove the sludge. The total length of the pipeline
was 70 metres. The inlet of the
pipeline was located near the
control panel; the kerosene so pumped into the VRM-II pipeline was collected in
a carboy.
At about 10.45 am, the pump was stopped.
In order to remove the residual kerosene from the pipeline, the Assistant Foreman used a Nitrogen gas cylinder at one end of the pipeline; he asked
a khalasi to connect a hose to the other end of the pipeline and hold the hose to a 200 litres barrel. By opening the Nitrogen gas cylinder and due to the
Nitrogen Gas pressure, about 20 litres
of residual kerosene was flushed from the pipeline and collected in the
barrel. As the Nitrogen gas in the
cylinder was exhausted, the Assistant Foreman brought an Oxygen Cylinder from
the nearby area and by using a regulator he connected the oxygen cylinder to
the inlet of the pipeline. At the other end, the khalasi was asked to insert
the hose from the pipeline outlet into the 2 inch opening of the 200 litres
barrel and hold it. At about 11.15 a.m., the Assistant Foreman, using the
Regulator, reduced the Oxygen pressure to 4 kgf/sq.cm. (g) and let in the Oxygen gas into the Lube oil pipeline with the intention of flushing out the entire residual kerosene
from the pipeline. In a few seconds, the barrel got exploded causing fire burn
injuries to the khalasi who was holding the delivery end hose to the 200 litres
barrel as well as to a Fitter/Welder and two contract workmen who were working
closeby.
Causes :
1.
Instead of using
steam or an inert gas, like Nitrogen, the Assistant Foreman used Oxygen
gas for flushing out the Kerosene from the pipeline. As kerosene is a flammable
liquid, using the Oxygen gas for flushing out the kerosene will certainly cause
explosion.
2. The khalasi was holding the delivery end hose into the 2 inch opening of the barrel which was already having about 20 litres of kerosene.
Insufficient vent in the barrel had caused
pressure build-up, resulting in explosion. (In fact, the 2 Inch vent opening of
the kerosene barrel was completely covered with the hose).
Case Study On
Accidents/Dangerous Occurrence For The Year 2004
1. In a chemical factory yellow phosphorous was converted into red phosphorous in a rotary
furnace. When the yellow phosphorous was cooked in the rotary furnace for its conversion to red
phosphorous at 244oc,
water
which was surrounding the yellow
phosphorous, became steam. When steam was vented, it carried away certain
amount of
phosphorous and this caused the vent line choke. This ultimately Increased the temperature and pressure of the vessel.
Temperature shot up to 300oC and pressure was not being monitored. Suddenly the furnace exploded and the stored up hot gases caused
flash fire injury on the worker and
subsequently he died.
Causes :
1.
The outlet for
the generated
steam and system pressure was chocked by the phosphorous and there was a pressure and there was a
pressure temperature built up in the vessel
2.
Pressure was not monitored by the pressure gauge installed in the
furnace
3.
No safety valve with the proper scrubber arrangement was not installed
in the furnace.
2. In a cashewnut
processing factory, 23 workers were working in a shed which formed a part of
the factory. The size of the shed was 20' x 60'. The truss of the tiled roof in the shed was made up of logs of coconut tree.
The height of the wall of the shed was 4”
& above the wall 1.5' x 1.5' pillars made up of bricks were
constructed without cement plastering.
Due to continuous
rainfall & gusty wind the brick wall lost its stability and the pillars
supporting the roof collapsed. The entire structure fell on the workers who were working and 3 workers died and 11
workers were injured.
Causes :
1.
The truss of the roof was constructed with logs of coconut tree.
2.
Pillars were
constructed with poor cement bonding and also without cement plastering.
3.
In a Chlor-Alkali
Plant, there were two Cell Houses, (viz.)
Cell House-! & Cell House-II. Cell House-I was being operated on Tamil Nadu Electricity
Board Power Supply and
Cell House II on Captive Power.
On 18-07-2004 at
06.02 P,M.. the Captive Power Plant
feeding electrical supply to Cell House - II got tripped due to a flashover (earth fault).
This resulted in the tripping of load in Cell House - II and a few motor drives
in other sections. But the Cell House-! continued to function, producing
Chlorine as it was being operated on TNEB Power. There was a Chlorine Scrubber system which was a packed column and whose function
was to absorb the chlorine gas by means of the circulating lime slurry, in the
event of any operational upsets in the process and chlorine free air was vented
to the atmosphere. There is a chlorine
gas compressor in the chlorine liquefaction section, the compressor sucks the
chlorine which is evolved in the cell during electrolysis and compresses it for
chlorine liquefaction.
Since both the
Chlorine scrubber blower and the Chlorine Compressor also got tripped along wlth the Cell House - II, the Chlorine gas which
evolved from the Cells of Cell House – II came out freely and drifted along
with the wind toward the adjoining villages, namely Mettur and Katturvalavu and caused
suffocation to about 24 villagers. They were admitted in the Mettur Government Hospital and were treated for
chlorine inhalation. No casualty.
Cause :
1.
Emergency power supply was not provided to the Chlorine absorption system
to meet out any problem of power interruption during emergency of chlorine leak
2.
Cell House – I and Cell house - II were not provided with interlock
arrangements in such a manner that if one cell house trips due to operational
problem, the other cell house also gets tripped instantaneously.
4. In a textile mill
there was a dangerous occurrence caused due to the collapse of partition wall separating the
third & the fourth compartments of the Cotton Mixing area. The said wall was 17' long 11' high
and ½' thick. It was just constructed
above the floor without any foundation.
Huge quantity of cotton were stored in the fourth compartment
whereas the third compartment was empty.
The partition wall separating the 2 compartments suddenly collapsed
clue to the stress developed by huge quantity "of cotton stored In the 4th
compartment
& fell on the workers in the 3rd compartment. Due to this 1 worker died and 3 were
injured.
Cause :
Partition wall was
constructed without proper foundation
5. In
a textile mill large quantities of cotton dust were deposited on the roof and over surface of the
tube lights provided for illumination.
Due to voltage fluctuation, spark was generated
from the choke of one of the tube lights and cotton dust deposited over the
tube light caught fire and fell on the sliver cans containing silver.
As a result of this fire spread to the other machines in that
hall and
caused damage to the machinery and no worker affected.
Cause :
Flame proof
electrical fittings were not
provided
6. In a fire works factory, lighting
arresters were provided only In crackers store room and not provided in any of
the manufacturing sheds. Lightning struck one of the manufacturing sheds and
the rockets, and other crackers stored in the sheds got exploded. As a result of this 7 sheds were totally
damaged and 3 sheds were partially damaged.
No worker was affected in this accident
Cause :
Lighting arrestors were not provided In the manufacturing shed.
Case Study On
Accidents/Dangerous Occurrence For The Year 2005
1. In a factory, Steel Ingots are
manufactured from iron scrap through induction furnace. Due to the cracks in
the ramming mass, lining the furnace, the hot metal in the furnace
penetrated through the cracks and punctured the S.S.. coil and a hole of about 5
mm. diameter developed in the SS ring due to this puncture. Hence, water from
the above S.S. coil leaked into the furnace which on contact with the hot
molten metal at 1550°C, inside the furnace resulted in formation of steam below
the furnace top. Due to high pressure developed in the furnace, the hot molten
metal from the top opening of the furnace splashed on the workers, working on
the platform as well as the side of the platform. Out of 15 injured workers 4
of them died.
Causes :
1.
The ramming mass lining
was not packed properly without any cracks.
2.
The work of segregation
of the iron was carried on the furnace platform
3.
Splash
arrestors are not provided all around and above the top opening of the induction
furnace.
2. In a factory,
where 10 MT weak sulphuric acid was stored, suddenly the suction line valve
tank nozzle assembly got broken and through this opening sulphuric acid drained
out from the tank and this resulted in vacuum formation in the tank. This FRP
tank hit against the supporting channel legs due to the formation of vacuum
Causes :
1.
The FRP tank was not maintained
with a adequate strength and stability
2.
The FRP tank was not tested and certified
by the Competent person every year
3. In a fire works factory during the process
of manufacturing flower pots, in order to load the Aluminium power mixture into
the paper cone, the paper cones were placed over a wooden tray and after loading they were beaten with a wooden stick. The wooden tray
used for this purpose had iron nails in the joints and small quantity of
aluminium powder had already spilled over
the tray. Due to friction between the iron nails and chemical mixture, spark emanated and the chemical mixture kept
nearby caught fire and resulted n explosion. Due to this explosion 2
workers died.
Cause :
Due to friction
between the iron nails and chemical mixture, spark emanated and
the chemical mixture kept nearby caught fire
and resulted in explosion.
4. In an ingots manufacturing factory, a
contractor was assigned the job of
cutting one old metal gas cylinder. While doing so, a small hole was cut by means of
gas cutting operation. Without
informing the pungent smell of
some gas. he left the factory. Through the hole, the chlorine gas emanated
from the liquefied chlorine, escaped and vapourised with air and
this affected the residents of
the village.
Cause :
Gas detector to indicate the leakage of gas was not
provided
5. In a
fire works manufacturing factory, rockets which was manufactured using aluminium power, potassium nitrate,
sulphur & charcoal were not
properly dried on the drying platform. In the wet stage, the rockets were kept in the working shed. Due to moisture
content, aluminium powder had undergone exothermic reaction and with the
evolution of heat, the rockets got exploded. As a result of this explosion 10 workers died and 3 working sheds
completely collapsed.
Cause :
Lighting arrestors were not
provided In the manufacturing shed.
1. Rockets, which were not properly dried had undergone exothermic reaction due to moisture content and with the evolution of heat, got exploded.
2.
Mixing and manufacturing sheds were not provided with
rubber mats on the floor
6. In a factory,
extraction of oil from rice bran was being carried on using hexane as a
solvent. On a day of accident, repair works to the gadder frames of the
extractor meant for transferring the rice bran was being carried on. A 40W
electrical hand bulb was used for providing lighting. When the worker was
holding the electrical hand bulb near the view glass opening, the hand bulb hit
against the view glass opening. Spark emanated due to this, ignited the hexane
vapour which was present in the extractor, a big fire consequently.
Causes :
1.
Oil extractor was not
purged with inert gas - nitrogen before
being taken up for maintenance activity.
2.
Electrical bulb and its
electrical wirings are not of flameproof construction.
7. In a fire works industry, the unfinished and
incompleted tubes containing the chemical mixtures of sulphur, aluminium
powder, barium nitrate, strontium nitrate, charcoal, dextrin & salt petre
were kept in the wooden box in the transit shed. Due to decomposition of the
chemical mixture the tubes exploded.
Causes :
1. Chemical mixture used for the
manufacture of fire works were kept in the
decomposition stage in the transit shed.
8. In a fertilizer factory,
as the granulator discharge chute got chocked the plant was stopped and the
workers cleaned the choked discharge chute by means of poking. After cleaning, the plant was, started
without feeding the raw materials namely phosphoric acid, sulphuric acid and
ammonia; the granulator was put on dry run.
Meanwhile, the heavy lump which caused the block in exhaust ducting fell
down and consequently the unreacted ammonia, came out from the discharge end in the form of
heavy puffing and injured 5 contract workers. They were given medical treatment
in Government hospital and were discharged later
Causes :
1. Un-reacted ammonia in the granulator
came out from the discharge end in the form of heavy puffing and injured the
workers
9. In a textile industry, when a cotton lap was
being processed in a carding machine, iron particles which were present in the
lap created sparks and this ignited the cotton waste materials in carding
cellar, blow room cellar and blow room MBO machine, resulting in big fire.
Causes :
1. Iron particles present in the
cotton lap created spark, when it was processed in the carding machine
10. In a pharmaceuticals manufacturing industry,
after the bulk drug is produced the solvents are recovered by distillation in
solvent recovery plant. In this instance, a flash distillation still, T-302 was
used for the recovery of solvent, Dimethly Sulfoxide (DMSO) in the Solvent
Recovery Plant. A batch
quantity of 5 KI. of 75% concentration DMSO was charged into the still T-302 in
which 700 mm. of Hg vacuum using a piston vacuum pump and a temperature of 136~
were maintained. When this batch was going on and 2.5 KI. of DMSO was inside
T-302, there was a hissing sound and immediately after the hissing sound was
heard by the worker the still T-302 got exploded with a fire ball, killing a
chemist and another chemical engineer. The control room which was located very
close to the Solvent Recovery Plant was heavily damaged in the explosion. There
were so many joints, flanges a gaskets in the pipe line along the DMSO vapour
route on the vacuum pump side. Hence failure of such parts might have led to
leakage of air in the circuit and could have caused air DM50 explosive mixture.
Causes :
1.
DMS0 is a
flammable liquid. It has a flash point of 80°C and flammable
range from 2.6% (voIume) LFL to 63% (volume) UFL. Hence when the still, T-302 is at 136°C, vacuum is
absolutely necessary to rule out air
entry and to prevent fire. Before the explosion, a hissing sound was heard by a
witness; this indicates that vacuum still, T-302 could have failed due
to development of hole (s) through which air entered and formed an explosion.
2.
As air
ingressed the still T-302, static charges could have been generated due to
mixing with the DMSO. The static charges generated could have ignited the explosive mixture, leading to
explosion and fire ball
11. In a factory, the
waste wood material was accumulated on the floor below the expansion tank and was not removed atleast once in a
day. The temperature of the thermic fluid
inside the expansion tank could have been higher than the designed value. Due
to high temperature there could be rise In pressure, which could have caused
the spillage. The flash point of thermic fluid was 220 degree celsius. The
required temperature at the hot press area was around 210 degree celsius. The thermic fluid was not tested for
suitability by a competent person once in every three months period. Variation
in specifications (acidity, flash
point,
suspended matter, viscosity and ash
content) of the thermic fluid
could have necessitated overheating and the flash point of the fluid
could have been reached. At flash point the thermic fluid spilled and
ignited the waste wood materials and caused this fire accident.
Causes :
1.
Variation in
specification (acidity, flash point, suspended matter, viscosity and ash
content) of the thermic fluid, could have necessitated overheating and the
flash point of the fluid could have been reached. At flash point the thermic
fluid spilled and ignited the waste wood materials and caused this fire
accident.
12. In a fine chemicals
manufacturing industry, chemicals like 2 – amino Di-bromo-benzly alcohol, manganese dioxide and toluene were loaded into the 4 KI. stainless steel reactor
(SSR5) and heated upto 65-70 degree centigrade and agitated in the above process. The resultant
product layer was settled and filtered in SS nutsche
filter by transferring through
a HDPE hose. The remaining layer containing toluene was unloaded in a 200 litre
HDPE barrel which was not provided with proper earthing or bonding to dissipate
the static electric charges and hence fire broke out and spread to the nearby nutsche filter and SSR 6 reactor.
Causes :
1. HDPE barrel which was not provided with proper earthing
or bonding to dissipate the static electric charges and hence fire broke out.