Chlorine Safety

1. CHLORINE USES
&
SAFETY MEASURES IN PRODUCTION AND USE
BY
H S SEHGAL

2. USES OF CHLORINE
Everyday Application
• Disinfectant and purifier
• Plastics and polymers
• Solvents, agrochemicals and pharmaceuticals
• Intermediate in manufacturing other substances.
• Used worldwide to purify water supply .
Household item ---
• Bleach and disinfectantto bullet-resistant vests,
• Computer hardware
• Silicon chips
• Automotive parts.

3. Raise Living Standards
• PVC-Most versatile polymer .
• Durable, easy to clean, stain resistant, lightweight,
corrosion resistant and needs no maintenance.
Other polymers :
- Flexible and rigid polyurethane
- Polycarbonates, used where strength is important.
- Temperature-resistant, non-stick PTFE for frying
pans, bakery tins and irons.
- Poly vinylidene chloride (PVDC) resins for their barrier
coating properties, particularly in food packaging.
- Vinyl swimming pool liners and soccer balls; golf bags;
nylon tents and water-proof jackets; wet suits and
inflatable rafts; surfboards; tennis rackets and many
children’s toys.

4. Raise Living Standards
• Car components, including: nylon for car seatbelts
and air bags; vinyl upholstery; bumpers and mats;
polyurethane seat cushions; dashboards; fan and
alternator belts; hoses gaskets and seals; petrol
additives; brakes and transmission fluids; and anti-
freeze.
• Chlorinated solvents as degreasing agents during
manufacture of metal components for aircraft
engines and car-braking systems.
• Responding to natural disasters, decontaminating
public water supplies damaged by floods,
tornadoes and earthquakes.

5. Raise Living Standards
• PVC window frames and plumbing pipes;
insulation; paint (make titanium dioxide, the non-
toxic white pigment used in paints); nylon
carpeting; and garden sprinkler systems.
• Toiletries and cosmetics, televisions and compact
discs.
• Chlorinated dry cleaning solvent, per chloro
ethylene, most widely used fabric and garment
cleaner since it was introduced about 50 years ago.

6. Medical applications
• Medicines- Allergies, arthritis and diabetes.
• Protect patients from infections through their use
in cleaning, disinfection and antiseptics.
• Prevent bacterial contaminationof patient’ burns
and wounds
• Disinfect kidney dialysis machines
• Clean and disinfect work surfaces and equipment
in medical labs
• Kill bacteria such as those which cause
Legionnaire’s disease, and which can live in
hospital water and air-conditioningsystem.

7. Medicines rely on chlorine
• Chlorine products treat Acids, allergies,
arthritis, cancer, depression, diabetes, heart
disease, hypertension, infections, pneumonia
and ulcers.
• Natural antibiotic vanco mycin, which is the
only effective in fighting hospital
Staphylococcus infections, or methylene
chloride, extensively used as a process
solvent for coating tablets.
• Important intermediate in the manufacture
of Vitamin C.

8. Medicines rely on chlorine
Medicines, which rely on chlorine chemistry:
• Chlorsiazepozide, tranquilizer chlorpromazine (pacifies
or calms)
• Clometacin analgesic (pain-killer)
• Chlorcycclizine antihistamine (relief cold and allergy
symptoms)
• Clobutinal antitussive (suppresses coughing)
• Clobenflural coronaty vasodilator (enlarges blood
vessels of the heart)
• Clonazepam anticomvulsant (prevents convulsions of
the heart)
• Clotdione anticoagulant (precents convulsions)
• Mitotane antineoplastic (inhibits growth and
formation of tumours)

9. Medicines rely on chlorine
• Safety in tamper-resistant pharmaceutical and in “blister”
packages, which help extend shelf life and make it easier
for the patients to take the correct dose.
• Used to make intravenous drips and blood bags, sterile
tubing and packaging, prosthetics and heart catheters.
• Slicer chloride is used for mammo graogy and x-ray films.
• Make semiconductors foot diagnostic instruments, and
polystyrene coolers for organ transplants.
• Common salt is the basic of intravenous saline solutions.
• Powerful disinfectant, added in small quantities to ensure
clean drinking water right up to the top.

10. Fighting diseases
• Chlorine was first used in drinking water in the 19th
century to control the spread of water-borne
diseases such as typhoid, cholera, dysentery and
gastro-enteritis.
• Remove tastes and odors,
• Controls the growth of slime and algae in main
pipes and storage tanks.
• Remove unwanted nitrogen compounds from
water.
• World’s drinking water depends on chlorination

11. Safety measures
•Training of personnel including:
• Basic knowledge of chlorine properties,
•Correct operating practice
•Emergency procedures,
•Frequent refresher training
•Making sure that contractors' personnel on
the site are familiar with the safety
•Regulations and procedures for the site

12. Proven life saver
• In US, annual deaths from cholera totaled 25000in
1900. In 1960, this figure has fallen to fewer than 20.
In 1991.
• In 1986, 4000 people in Tenerife wee hospitalized due
to water contamination, which followed the
withdrawal of chlorine.
• Products are effective and economical as household
bleach
• Disinfectant to destroy and deactivate a wide range of
dangerous microbes in homes, hospitals, swimming
pools and spas, hotels, restaurants and other public
places.
• Ferric chlorine acid and hydrochloric acid-are used to
purify wastewaterand sewage.

13. Public safety
• Protective equipments for police, fire fighters
• Protective helmets and face shields .
• Bullet-resistant glass is made from polycarbonate.
• Bullet-resistant vests comprise armed fibers.
• Communications equipments such as radios, TV’s, micro
processors and computer parts .
Prevention is better than cure—avoid chlorine
releases at home
Three ways to avoid chlorine in and around home”
1. When using a dry, chlorine-based swimming pool sanitizer.
Always add the sanitizer tot the pool. Never mix water into pool
treatment chemicals.
2. Never mix different types of swimming pool sanitizer together.
3. Never mix household chemical compounds with ammonia or
acid-based household chemicals.

14. Extra facts --Window in the sky
• There is a layer in the atmosphere, about 25km above
sea level.
• This layer of gas helps to support life on earth.
• No organisms can exist without it.
• It is called the ozone, a form of oxygen.
• The ozone protects life on earth by absorbing UV
radiation so that the harmful UV rays cannot reach the
earth’s surface.
• Industrialization by mankind in the past century has
produced many chemicals which destroys ozone.
• A hole in the ozone layer appears above Antarctic
every spring.
• One main culprit is chloro fluoro carbons, or CFCs.

15. Extra facts --Window in the sky
• This substances is released into the air by coolant
fluids used in refrigerators,air-conditioners.
• CFCs in the air is broken up into chlorine atoms.
• These chlorine atoms eat up the ozone without
themselves being destroyed.
• Destroy more ozone molecules repeatedly.
• One Styrofoam plate is capable of destroying an area
in the ozone larger than a football field!
• Too much UV radiation is harmful to our health.
• It causes burns, skin cancer and cataracts.
• UV also kills planktons, disrupting the chain and
upsetting the natural environment.
• What will happen if man continues to release CFC into
the air?

16. Concerns regarding chlorine usage
• Chlorine reacts with many naturally
occurring organic and inorganic
compounds in water to produce
undesirable DBPs.
• Hazards associated with using chlorine,
specifically chlorine gas, require special
treatment and response programs.
• High chlorine doses can cause taste and
odor problems.

17. Safety and Handling Considerations
• Chlorine gas is a strong oxidizer.
• Classifies chlorine as a poisonous gas .
• Regulate the storage and use of chlorine.
• Storing more than 5 tonners/cylinders in INDIA are
subject to safety program.
• Process Safety Managementstandards .
• The Risk ManagementProgram Rule administered
by EPA .
• All of these regulations must be considered during
the design and operation of chlorination facilities .

18. Disadvantages
• Cause a deterioration in coagulation/filtration of
dissolved organic substances
• Forms halogen-substitutedbyproducts
• Taste and odor problems in water quality
• Chlorine gas is a hazardous corrosive gas
• Special leak containmentand scrubber facilities
could be required for chlorine gas
• Sodium and calcium hypochlorite are more
expensive than chlorine gas
• Sodium hypochlorite degrades over time and with
exposure to light
• Sodium hypochlorite is a corrosive chemical

19. Disadvantages
• Calcium hypochlorite must be stored in a cool, dry
place because of its reaction with moisture and heat
• A precipitate form in a calcium hypochlorite solution
because of impurities, therefore, an anti scalant
chemical may be needed
• Higher concentrations of hypochlorite solutions are
unstable and will produce chlorate as a byproduct
• Is less effective at high pH
• Forms oxygenated byproducts that are biodegradable
and which can enhance subsequent biological growth
if a chlorine residual is not maintained.
• Release of constituents bound in the distribution
system (e.g., arsenic) by changing the redox state.
•

20. VENTILATION WHILE WORKING WITH CHLORINE
•Potential for direct exposure to Cl2 during cylinder changes
and making small repairs to the chlorine system,
• Use of a supplied air or self-contained breathing apparatus
is recommended.
• To use air-purifying respirators, the exact chlorine
concentration is required.
• Ventilation should be supplied at the floor level.
• Replace the lead or fiber washer each time you change a
chlorine cylinder regardless of the condition of the old lead
or washer.
• When entering a room containing chlorine, check the proper
functioning of the chlorine monitor
• Turn on the ventilation system, and keep the door open.
• Have someone stand by in case of an emergency.

21. TYPICAL CHLORINE HANDLING ISSUES
• Containers in transit –road accidents
• Deliveries –e.g. offloading on tyres
• Connection/Disconnection –not
following procedures
• Incorrect spanners for opening and
closing valve
• Untrained operators
• Insufficient PPE (Full face mask!!)

22. INDIAN REGULATIONS
• Manufacture, Storage, Import &
Hazardous Chemicals Rules, 1989
• Chemical Accidents (Emergency
Planning, Preparedness and
Response) Rules, 1996
• Public Liability Insurance Act, 1991
• Public Liability Insurance Rules, 1991
• Factories Act 1948
• Gujarat Factories Rules 1963, as
amended 1995
• Motor Vehicles Act, 1988 and Rules 1989
• Gas cylinder Rules 2004

23. Major Hazardous Installation (MHI)
Step 1: Draftingown internaland external
Emergency plan.
Step 2: Local authority Fire Brigade Inspection Officer
to assist
Step 3: SpecificFire Bylaws compliance
Step 4: Local authority will establishthe need to
register for MHI
Step 5: Certified officers to compile MHI…(process)
Step 6: Local Authority to approve MHI

24. Storage of Hazardous products
• Application of the National Building
Regulations
• Compliance to guidelines
• Local authority Fire Brigade Inspection
Officer to approve building
• Issue certificate -license

25. Chlorine Gas
• Chlorine gas is relatively inexpensive and doesn't
produce by-products such as chlorite or chlorate
ions.
• For companies and municipalities concerned
about budgets, chlorine gas is very attractive.
• Two disadvantages of chlorine gas are toxicity and
corrosiveness.
• A more serious disadvantage of gaseous chlorine is
the total cost of handling and operating safety.
• Regulations limit the amount of gas that can be
stored at a single location without extensive
provisions to contain potential leaks.

26. Chlorine Gas
• On-site storage of large quantities of gas
must be enclosed in and protected by
systems called “scrubbers”
• Ability to contain and neutralize gas in the
event of a leak.
• Scrubbers are costly to purchase and install,
and require regular maintenance.
• Operators must have an emergency
response plan in place.

27. Chlorine Gas
• Maintenance costs to wear protective
breathing gear when handling containers or
providing maintenance on the systems even
with the smallest installations.
• Cost associated with is the record-keeping
and reporting required.
• Labor costs of using chlorine gas.
• Overall related costs of using chlorine gas can
far outweigh the cost of the gas itself.

28. safety precautions for chlorine containers
• Kind of gas, weight, owner, producing date and date of the
last testing
• To be noted clearly on the container.
• Chlorine containers are marked by golden yellow color.
• No changes or repair by the user!
• Never open container valves by force.
• Stuck valve spindles can be loosened by wrapping a shred
with warm water around the valve.
• Never use an open flame!
• Never use wrench lengthening!
• Return containers with stuck valves to the manufacturer.
Observer safety precautions and the manuals of the
manufacturer!

29. Chlorine Gas
• Health effects resulting from most chlorine
exposures begin within seconds to minutes.
• Gas causes both internal and external blisters
on the victim within hours of being exposed
to it
• No antidote for chlorine poisoning.
• When liquid chlorine is released, it quickly
turns into a gas that stays close to the ground
and spreads rapidly.
• When chlorine gas comes into contact with
moist tissues such as the eyes, throat, and
lungs, an acid is produced that can damage
these tissues.

30. Safety practices for avoiding the risks and hazards
BASIC INFORMATION ABOUT CHLORINE IN THE MSDS
• The MSDS explains the hazards of and what precautions
to take when handling, storing and using chlorine.
• At room temperature, chlorine is a greenish-yellow gas,
and an amber color as a liquid.
• Chlorine is heavier than air.
• Chlorine monitoring instruments must be capable of
taking measurements near the floor.
• Cl2 reacts with water to form hypochlorous acid and must
be isolated from water until proper mixing can occur.

31. Safety practices for avoiding the risks and hazards
• Make sure piping is dry before admitting chlorine.
• Use only dry, oil-free air for purging;
• Never use water to test for chlorine leaks.
• Chlorine is non-flammable but reacts violently with
some chemicals.
• Frostbite occurs if chlorine liquid is splashed on the
skin.
• If chlorine gas is swallowed, severe burns to the
mouth, throat and stomach will be expected.
• Serious burns to eyes are also potential hazards.
• Cl2 reacts violently with oil and grease creating
spontaneous combustion.
• Chlorine expands very rapidly.

32. Water chlorination
• Taste and odor control;
• Prevention of algae growths;
• Maintenance of clear filter media;
• Removal of iron and manganese;
• Destruction of hydrogen sulfide;
• Bleaching of certain organic colors;
• Maintenance of distribution system water quality by
controlling slime growth;
• Restoration and preservation of pipeline capacity;
• Restoration of well capacity, water main sterilization;
and
• Improved coagulation by activated silica.

33. Operational Considerations
• Mixer usually creates the required vacuum.
• The injector uses water flowing through a Chlorine.
• Liquefied chlorine gas is typically evaporated to
gaseous chlorine prior to metering.
• Chlorine gas is typically fed under vacuum conditions.
Either an injector or a vacuum induction venturi to
draw the chlorine gas into a side stream of carrier
water to form a concentrated chlorine solution.
• This solution is then introduced into the process water
through a diffuser or mixed with a mechanical mixer.
• A vacuum induction mixer uses the motive forces of
the mixer to create a vacuum and draws the chlorine
gas directly into the process water at the mixer.

34. Advantages
• Oxidizes soluble iron, manganese, and sulfides
• Enhances color removal
• Enhances taste and odor
• Enhance coagulation and filtration of particulate
contaminants
• Effective biocide
• Easiest and least expensive disinfection method.
• Widely used disinfection method.
• Available as calcium and sodium hypochlorite.
• Use of these solutions is more advantageous for
smaller systems than chlorine gas
• Are easier to use, are safer, and need less equipment
compared to chlorine gas
• Provides a residual.

35. Special Considerations
• Chlorine is such a strong oxidant and
extremely corrosive,
• Special storage and handling
considerations be considered in the
planning of a water treatment plant.
• Health concerns associated with
handling and use of chlorine is an
important consideration.

36. LEAKS IN CHLORINE CYLINDERS AND SYSTEMS
• Use tools approved for the work atmosphere.
• Leak test the cylinder by spraying an ammonia solution onto the cylinder
joints.
• A leak is indicated by white cloud or mist that is formed when ammonia
reacts with chlorine.
• If a leak is detected, notify your supervisor and follow your organization’s
emergency action procedures, including calling the fire department and
the HAZMAT team.
• Approach a leak with appropriate respiratory protection, protective
clothing, gloves, and other safety equipment.
• Leak repair kits are available.
• Leaks typically occur at valve packing, plugs, and at defective valves.
• Development and implementation of contingency and rescue plans are
essential for companies using chlorine.
• When a leak occurs, never attempt to repair it alone.
• For additional information in the event of an emergency, contact the
FILLER

37. FIRST AID
• First aid for chlorine victims must be approved by
company and physician.
• Remove the victim to fresh air
• Keep the victim warm and quiet.
• If the eyes or skin come in contact with chlorine,
flush them with flowing water for 15 minutes.
• Remove contaminated clothing and transport to a
hospital at once.
• Even a small dose of chlorine gas can cause
pulmonary edema.

38. SAFETY MEETING OR TRAINING
• Make everyone aware of the importance the company
places on health and safety and how each person
must be an active member of the safety team.
• Introduce the videotape program.
• Play the videotape without interruption.
• Review the program content by presenting the
information in the program outline.
• Review questions and ask each participant to interact
• Copy the attendance record as needed and have each
participant sign the form.
• Maintain the attendance record and each
participant's test paper as written documentation of
the training performed.

39. Cl2 Program
• Major chemical characteristics of
chlorine
• Proper container handling techniques
• Ventilation requirement during
handling
• How to respond to leaks
• First aid procedures
• How to prevent chlorine exposure by
household chemicals

40. Safety measures
• Identification and Evaluation of Major hazards
• Written information for personnel about safety
measures in normal and abnormal conditions
• Instructions for Safe Operation
• Permanent monitoring of the installations under the
responsibility of a designated person specially trained
for chlorine hazards ,
• Good compliance with safety parameters defined in
the safety report, including periodic inspection and
control of materials specified according to safety
hazards
• Maintenance programs for the installations: for
example, storage, maintenance of pipe work, pumps,
compressors, monitoring of moisture concentrations,
impurities in liquid chlorine

41. Emergencies and Recording of Accidents
and Near-Misses
• Preparation, test and review of emergency plans
• Safety managementsystems completed with
appropriate technical measures.
• High quality preventiveand protective systems, in
particular in the loading area
• Enhanced leak detection and leak isolation
• Good protection of employeesand temporary
workers on the site with appropriate and well
maintainedequipment
• Storage at low temperature

42. Chlor -Alkali Plant
Prevention of liquid chlorine spillage---
• Overfilling protection systems
• Correct choice of construction material and regular
inspection of vessels
• Bunding for vessels containing hazardous material
And also:
• Preventing impurities to avoid any explosive mixture.
• Measuring and control of hydrogen concentration in
the chlorine gas from the cell room and after each
liquefaction step, and measuring
• And prevention of possible NCl3 accumulation.
• Prevention of failure of the electrical supply.

43. Chlor -Alkali Plant
• Emergency generators for supply of power to vital
equipment when/if grid power fails and also the
prevention of failure of the instrument air supply.
• Prevention of chlorine releases by a collection of
chlorine releases during maintenance operation to the
absorption unit,
• A correct warning for process deviations and
irregularities.
• Good layout of the installationand provision for
instant shut-down of some compartments help to
prevent domino-effects.
• Manual emergency push buttons which can be used
by any of the site personnel on discovery of a chlorine
leak should be present around the plant.
•

44. Loading Area
• Weakest link is the connection between the static plant and
the mobile tank.
• Use of pneumatic valves with automatic shut down in case
of failure of the link, at both ends of the link, is essential to
limit the leak.
• Risk assessment study, to each installation, can give the
most likely modes of failure during loading and the
associated safety measures to avoid them.
Examples of some standard measures are:
• Improved chlorine detection and location and rapid
isolation of sources feeding a leak
• Connection of loading area to a chlorine absorption system
• PTFE hoses should not be used (based on information
reported to accident databases)
• Articulated arms or correctly specified flexible hoses and
coils for chlorine transfers

45. Loading area hazards Examples of preventative measures Examples of corrective or emergency measures
- Tank overfill - Overfilling protection of the transport vehicle: a
double weighing installation (two weighbridges
operated by two different workers) should be
installed
• Warning for loading deviations and
irregularities
• Automatic pump shutdown
• Chlorine detectors connected to alarms in
the control room
• Remotely controlled shutdown valves
• Emergency procedures
• Tank over-pressurisation during filling - Venting procedure to remove inert gases • Supply pump can be tripped manually or
from control room
- Corrosion due to chlorine/water reaction - Check tare weight of tank
- Moisture control systemand avoidance of
possible back-flow
• Moisture analysis in chlorine gas and
padding gas, with alarm
• Response by process operators to evidence
of ferric chloride in valves
• Suction failure alarm in vent gas scrubbing
system
• Fire due to chlorine/iron reaction - Use of appropriate materials
- Avoidance of "hot work" areas
- No flammable liquids or materials in the
surroundings of loading areas
- Fire due to contaminants (oil, organics) - Prohibition of use of hydrocarbon oils, greases
and solvents
- Use of oil-free compressors in padding gas
systems
- Internal corrosion • Moisture control systemin chlorine and
avoidance of possible back-flow
• Monitoring procedures for wet ferric
chloride in valves
Preventative and corrective or emergency measures to avoid accidents at loading areas of a chlor-alkali

46. • Fire due to chlorine/iron reaction - Use of appropriate materials
- Avoidance of "hot work" areas
- No flammable liquidsor materialsin the
surroundings of loading areas
- Fire due to contaminants (oil, organics) - Prohibition of use of hydrocarbon oils, greases and
solvents
- Use of oil-free compressors in padding gas systems
- Internal corrosion • Moisture control system in chlorine and
avoidance of possible back-flow
• Monitoring procedures for wet ferric chloride in
valves

47. - Collision with other rail/road tanks • Braking the transport vehicle and blocking
the road or railway track during loading
• Prevention of runaway rail wagonsor
tankers getting into filling area
• Alarms linked to rail retarders
- Emergency shut off valves on tank and supply
initiated by push buttons
- Rupture of the filling pipe - Containment of the loading installation
• Use of articulated arms or correctly specified
flexible hoses and coils for chlorine transfer
• Maintenance and inspection procedures
- Emergency shut-off valves
- Connection of dissipated chlorine gas from the
transport vehicle to the chlorine destruction unit
Other causes:
- Liquid chlorine in vent
- Back-flow of chlorine into padding gas system
- Valve leaks
- Control procedures on gas supplies system to avoid
over-pressurisation due to warming
- Avoidance of possibility of inversion on the
connection between liquid and gaseous phases
• - Liquid chlorine in vent detector (alarm/trip) to
alert operator
• - Increasing venting rate and draining liquid to
vented tanks
• - High and low pressure alarms on padding gas
system
• - Padding gas chlorine detector and differential
pressure control

48. Storage tank hazards Examples of preventative measures
Examples of corrective or emergency
measures
- Vessel failure due to over pressurisation (vapour
padding/ inert, liquid overfill)
• Physical tank protection against over-
pressurisation or hydraulic overfill
• Maintain stock tank pressure below the
maximum allowable pressure
• Pump maximum discharge pressure less
than maximum allowable system pressure
• Design standards of pump, pipework and
vessels
- High-pressure alarms on stock tanks
- Two independent level/weight alarms on
receiving tank
- Relief valves at appropriate settings and
capacities. It includes, in series: a bursting disk
protecting the valve from corrosion; a detection
device giving an alarm in case of failure of the
disk; a protection against corrosion due to back-
flow of moisture from the absorption unit. A
protective membrane may be used, or a
continuous flow of inert dry gas may be added
after the valve.
• Pump trips at high level and/or pressure
• Pump can be tripped remotely
• Internal explosion due to build up of NCl3 • Never allow liquid chlorine to evaporate
completely to dryness; no branches or wells at
bottom of small tanks; brine quality control
• Internal explosion due to hydrogen • No direct connection between a chlorine storage
tank and a chlorine gas stream containing
hydrogen
• Contamination with organics • Prohibition of use of solvents or organic drying
agents
- Contamination with oil • Prohibition of use of oil or hydrocarbon
greases, use of oil-free compressors in
padding gas system
- Fire due to chlorine/iron reaction - Use of appropriate materials
- Avoidance of "hot work" areas
- No flammable liquids or materials in the
surroundings of loading areas

49. - Corrosion due to chlorine/water reaction;
internalcorrosion
- Check tare weight of tank
- Moisture control system and avoidance of
possible back-flow
• Alarm on padding gas moisture indicator
• Response by process operators to
evidence of ferric chloride
• Chlorine monitors on cooling waterside of
heat exchangers
- External corrosion • All stock tanks operated at temperatures
below zero insulated; fully watertight lagging
where freeze/thaw conditions exist
• Pressure vessel inspections include selective
removal of insulation to permit inspection of
external surfaces
- Low temperature thermal stress • Tanks have to be stress-relieved to prevent
failure from high induced stress
• Prohibit excessive physical force on valves
• Use of steel resilient at low temperature (-40
°C)
- Pump failure • The pump shall be equipped with high
temperature alarm
• Pump should be bunded
• Pump design specifications respected
- Chlorine detectors close to the pump

50. Economics
• General Electric Plastics in Bergen op Zoom (Netherlands)
Cryogenic storage of chlorine includes:
• 1 tank of 58 tonnes currently in use,
• 1 full tank of 58 tonnes and 1 emergency tank.
• All tanks are kept at -34 °C and atmospheric pressure.
• The whole storage is contained inside a building of 8000 m3.
• The chlorine absorption unit is 11 m high and 1.8 m in
diameter.
• A fan allows a continuous venting of 5000 m3/h.
• The cost of the storage built in Bergen op Zoom in 1988 is
estimated at about 4.3 million euros (10 million NLG,
exchange rate 1998)
• Maintenance cost at about 2% of the building cost.

51. Economics
ICI in Wilhelmshaven (Germany),
large quantity chlorine storage:
• 2 tanks of 1600 tons each
• 1 emergency tank.
• Chlorine is stored in steel tanks enclosed within a
shell constructed ofsteel/polyurethane/aluminium
sandwich material.
• This storage was built in the 1970s and cost about 7.7
million euros (about 15 million DEM).
• This storage was the solution at that time to a specific
situation;
• Today it might not have been built for such large
quantities.

52. Economics
ATOCHEM in Jarrie (Isère, France),
loading area:
• Containment of a separated loading area
(2 x 58 tonnes railway tanks),
• Chlorine destruction unit
• Water spray equipment.
• Cost was approximately 1.5 million
euros (September 1998).

53. Chlorine absorption unit
• Purpose of the chlorine destructionunit is to avoid large
emissions of chlorine gas to the environmentduring
irregular plant operationand/or emergencies, and to
take care of all chlorine-containingwastegases during
normal operation.
• Most common way to destroythe chlorine is to absorb
in weak caustic soda to produce sodium hypochlorite.
• Absorptionsystem can make use of packed towersor
venturi ejectors.
• Packed columns, though more complex, are betterin
case of emergencyif electricitysupply fails.
• Continueto absorb chlorine from a pressurerelief
system using causticsoda storedin a gravity-fed head
tank.

54. Chlorine absorption unit
• Concentration of caustic soda should not exceed
22% NaOH because of the risk of salt deposition,
causing blockages in the absorption plant, and
freezing.
• Design of an absorption system requires clear
specifications of:
• Maximum quantity of chlorine
• Composition of the gas stream
• Maximum instantaneous flow

55. Chlorine absorption unit
• To ensure that in case of a major accident, a massive release of
chlorine could be absorbed.
• The size of the unit is of great importance and should be
calculated to cope with emergency conditions.
• Caustic soda supply and the storage capacity for caustic soda and
hypochlorite solution should be correctly sized as well. It is
essential that faults are detected quickly and adequate
instrumentation with alarms should be applied at the vent
absorption plant to ensure that warning is given if equipment
fails.
• Temperature control of the absorption solution is essential, as is
measurement to prevent over-chlorination.
• The emergency power supply should be tested periodically.
• If the sodium hypochlorite cannot be sold, it has to be treated
before it is discharged.
• Several technologies are available to destroy sodium
hypochlorite without generating significant cross-media effects,
in particular catalytic processes.

56. Main achieved emission levels
• Absorption units designed to limit the chlorine content to
below 5-10 mg/m3 in the emitted gas in the worst case
scenario.
• Under normal operation concentration of chlorine is less
than 1-3 mg/m3 in the case of partial liquefaction
• Less than 3-6 mg/m3 in the case of total liquefaction.
• This level should tend to zero.
• Methodologies such as HAZOP (Hazard and Operability
Study), HAZAN and QRA are designed to ensure that the
operation of a chlorine installation poses a negligible risk
to employees, the neighboring public and the natural
environment.
• Use of checklists is useful methodology to reduce the risk

57. METHODS AND RESULTS
• Chlorine is stored in amounts ranging from 150 kg to 2.5 t,
• Found at unexpected and poorly protected sites.
• Sometimes even being forgotten.
• Two years ago, 300 kg of chlorine were detected in an old
and abandoned pool for medical rehabilitation in a densely
populated area of the city.
• Difficult to find a site in the city which further endangered
by either of the two chemicals in case of an accident due to
any reason.
• An act of sabotage should by no means be ruled out.
• Extremely efficient and simple way of causing damage or
endangering human health.
• Storage facilities built with poor protective and accident-
preventing systems,
• Protection from a potential terrorist attack does not exist at
all

58. METHODS AND RESULTS
• Chemicals-chlorine and ammonia, produce a vigorous and explosive
interaction,
• Each of them is extremely life- and health threatening.
• Chlorine storage had two 1000-kg chlorine containers situated right above
a crowded and densely populated area.
• Accident simulation with complete destruction of one of the chlorine
containers in the present conditions of total absence of efficient measures
for disaster prevention or disaster consequence reduction was performed,
taking into account unfavorable weather conditions with a most common
northeast wind of 2 m/s in a densely populated area within 250 m from
the site of accident,
• Risk of life would begin 2 minutes from the accident and would last for at
least 30 minutes, when atmosphere concentrations would decline below
those causing death on the spot in those found outdoors.
• An area within storage would be highly endangered.
• High chlorine concentrations in the atmosphere, lethal chlorine
concentrations would be reached indoors within the chlorine
contaminated area of 250 m in a few minutes.
• At least 10,000 people would be at high danger, and hospital capacities of
the city of Zagreb would be inadequate to. provide care for such a great
number of patients suffering from, e.g., lung edema due to chlorine
exposure

59. METHODS AND RESULTS
• Chlorine risk limited to lower floors and to the
unprotected people on the streets.
• Chlorine storage of 300 kg is located at about 150 m
above the Umka tunnel entrance,
• With wind blowing in such a direction that it would
drive chlorine into the tunnel
• There was no plan of emergency action in case of an
accident at the storage.
• Storages located at swimming pools highly frequented
during summertime, poorly maintained and
completely lacking any supervision have often been
detected.
• Highest proportion of accidents has been recorded at
swimming pools due to chlorine.

60. Accident Reasons
Deficiencies
• Poorly educated personnel and complete lack of their training
• Lack of efficient plan of emergency intervention
• Inappropriate instructions (procedures elaborated in writing) that
actually pose more serious threat than their nonexistence;
• Lack of a reliable burglary-proof system with alarm and
telecommunication on increased storage concentrations of
gaseous toxin;
• Lack of a system for limitation of accident consequences, e.g.,
hazardous substance neutralizers or water curtain device;
• Total lack of risk data in the local community, and especially on
the procedures for healt and life protection in case of accident;
and other (e.g., poor maintenance of liquefied gas containers).
• All these factors increase the risk of accidents involving
hazardous substances., with potential risk for human health
within a certain area from the respective storage

61. Accident Reasons & Prevention
• Continuous training, with development of mandatory
intervention plans for prevention of accidents and
reduction of their consequences.
Intervention plans,
1.Field of health care
2.Field of environmental control.
• Clear and properly written procedures for all activities,
accident prevention, and intervention in case of accident,
first aid and decontamination, communication with all
services in charge of intervention, notification and
population protection, medical procedures in care for
casualties, etc., have a crucial role.
• In charge of these issues in the companies involved
consider the development of written procedures mere
formality.
• Mistakes in the first aid and decontamination procedures.
• Point out common mistakes during education.

62. Accident Reasons & Prevention
• Exposure to gaseous ammonia via respiratory system state
that breathing should be done through a piece of cloth
soaked in acetic acid, with similar instructions fox skin or
eye decontamination upon acid or alkali
Spilling.
• Instructions for citizens on the procedures in case of
accident with a gaseous chemical also are quite risky,
especially when a decision on evacuation or confinement to
airtight spaces is to be made.
• We insist on mandatory simulation of the movement of a
gaseous toxin cloud at most unfavorable weather
conditions, which should be used as a basis to decide when
and at what distance from the risk facilities particular
population protective procedures should be performed.
• Population involved properly informed on the potential
hazards in their neighborhood and on the modes of self-
protection.

63. CONCLUSIONS
• Besides educationand clear procedures providedin writing,accident
preventionincludesmany other factors.
• In additionto continuousand quality maintenanceand service of the
system,efficientpreventionof uncontrolledentry in the facilitiesand
telecommunicationfor all potentialhazards such as attempted
burglaryor detectionof gaseous toxin leakagewithinor outsidethe
facilitiesare consideredto be of utmost importance.
• Developmentof neutralizers appears to be appropriatein case of usual
liquefiedgas evaporationon pipelineor valveaccidents, however,
variousother possibilitiesshould be anticipatedfor so-called worst
cases when any neutralizerwould turn inefficient.
• Responsiblepersons and services should be promptlynotified,at the
same time trying to buy some time and to preventimmediaterelease
of all the amounts of liquefiedgas, thus to be able to warn and protect
the populationon time.
• Each facilitypresentsa specific case, and that all possiblemodes of
delayingthe developmentof the worst case shouldbe carefully
studied

64. CONCLUSIONS
• Construction of a collecting basin under the ammonia
container with hermitization of all outlets in the main
engine-room of 1800 m3, except for one outlet on the
building in front of which a device for preparation of a
highly efficient water curtain should be mounted.
• For other facility with another toxin, the situation
would be different, pointing to a conclusion that each
risk site should be approached individually on
assessing the hazards and determining the measures
for risk reduction.
• Most important of all is to change the awareness of
those employed in risk facilities,
• This issue should be paid most time and attention
indeed.