Safety of Chlorine Handling

8/2/2019 Safety of Chlorine Handling

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(A) Important Properties of Chlorine related to Safety

Physical Properties : At room temperature, it is a yellow-green gas with a sharp, burning odor. In liquid phase itis clear, reddish colored liquid.Under increased pressure or at temperatures below -30 degrees F. or above the thresholdquantity of 1,500 pounds Chlorine presents a potential for a catastrophic event.Specific Gravity = Gas, 2.485 (air); Liquid, 1.467 0/4C (water) (Heavier than air as gasand water as liquid)Vapor Pressure = 53.51 psi at 0C; 112.95 psi at 25C - Evaporation is total no residue leftSolubility in Water =6.93 lbs/100 gals. (60F and 14.696 psi)- Minor solubility

Chemical Properties 1. Flammability Chlorine, gas or liquid, is non-explosive and non-flammable. It is an oxidizer and is capableof supporting combustion. Many organic chemicals react readily with chlorine, sometimesviolently.2. Reactivity

Reactions With Water - Chlorine is only slightly soluble in water.(0.3 to 0.7 percent)Reactions With Metals - At ordinary temperatures dry chlorine, gas or liquid, reacts withaluminum, arsenic, gold, mercury, selenium,tellurium, tin, and titanium. Carbon steelignites near 483F(251C).

Reactions With Organic Compounds - Chlorine reacts with many organic compounds. Somereactions can be extremely violent or explosive.

It is a highly reacting helogen combining directly nearly all elements hence isolation is theprimary requirement for safety.

(B) Exposure to human body and ill effects

Exposure to chlorine can cause immediate burning of the eyes, nose, and throat, warning of potentially hazardous exposure levels. Short-term exposures to chlorine do not often resultin long-term health effects. Long-term effects are usually found in people who have hadrepeated exposures to chlorine causing them to build a tolerance to its irritant effects,making victims unaware of the chemical's presence. Repeated chlorine exposure irritatesthe lungs, leading to coughing, mucus production, or shortness of breath which can last formonths, even years. The very young and elderly, as well as people with known healthproblems are at increased risk from chlorine exposure.

Common Routes of Chlorine Exposure Inhalation. The most common way for chlorine to enter the body is through the respiratorysystem. Chlorine is a respiratory irritant. The gas irritates the mucus membranes and theliquid burns the skin. As little as 3.5 ppm can be detected as an odor, and 1000 ppm islikely to be fatal after a few deep breaths. In fact, chlorine was used as a war gas in1915.Exposure to chlorine should not exceed 0.5 ppm (8-hour time-weighted average - 40hour week.)

Signs and symptoms of chlorine inhalation include: rapid, difficult breathing; bluish skincolor; wheezing and congestion; cough; nausea and dizziness; burning, irritated throat;swelling or narrowing of the airways; chlorine-induced pneumonia; and possible lungcollapse.


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Absorption through the Skin.Chlorine can be absorbed through the skin causing mild to severe burns. Symptoms include:pain, inflammation or swelling, blisters, frostbite, and tissue death.Absorption through the Eyes.Chlorine can be absorbed through the eyes causing various problems. Symptoms mayinclude: burning or discomfort, irregular blinking, redness, tearing, involuntary closing of

the eyelids, eye burns, eye pain, and blurred vision.Ingestion. Chlorine may cause tissue injury upon swallowing.

(C)Working safely around chlorineContainers

Liquid chlorine comes in two types of containers: - Cylinders with a 68 kg (150 lb.) capacity- Ton containers with a 907 kg (2000 lb.) capacityCylinders and ton containers have fusible plugs designed to melt at 71C when containersare exposed to extreme heat, such as fire, the plug melts, relieving pressure and preventingthe container from rupturing violently.

Storing chlorine - Do and Don'ts

Location Requirement : q Use signs to clearly identify all areas where chlorine is used or stored. Only qualifiedpersonnel are permitted to enter these areas.q Store chlorine cylinders and containers in a cool, dry, and relatively isolated area,protected from weather and extreme temperatures. If storing cylinders and containersoutside, shield them from direct sunlight, unless they are specifically designed for unshaded, outdoor storage.q Note: Never apply heat to pipes, containers, or container valves unless they have beenthoroughly purged of chlorine.q When storing chlorine containers inside, store the containers in a well-ventilated building,away from any heat sources, such as steam pipes.q Store chlorine containers on the lowest working level but not below grade.q Do not store chlorine near busy roadways or anywhere else where vehicles operate.Chlorine reacts with carbon monoxide to produce phosgene, an extremely poisonous gas.q Store cylinders upright and secure them against falling. Cylinders will discharge vaporswhen upright and discharge liquid when upside-down.q Store ton containers on their sides, on steel or concrete supports. The supports should beequipped with trunnion wheels so that, if chlorine leaks from the bottom valve, thecontainer can be quickly rotated with the leak at the top to minimize leakage. Discharge toncontainers while they are horizontal, with the two valves in a vertical line (vapour from thetop valve, liquid from the bottom).Housekeeping in Storage place

q Do not store materials that may react violently with chlorine in the same room as chlorine(for example, hydrogen, ammonia, acetylene fuel gases, ether, turpentine, and mosthydrocarbons, such as solvents, greases or oils, finely divided metals, and organic matter).q Store containers with enough room between them to allow for complete accessibilityduring an emergency.q Use cylinders and containers on a "first-in, first-out" basis.q Clearly tag or mark empty cylinders and separate them from full cylinders.q Note: Never assume a container is empty and therefore non-hazardous even though itmay weigh empty.


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Handling chlorine - Do and Don'tsMoving containersq Handle containers with care while moving or storing them. Do not allow containers tostrike objects and do not drop containers.q Do not use slings or magnetic devices to move chlorine containers.q Use new gaskets as recommended by the chlorine supplier each time a cylinder or

container is connected.q Follow the chlorine supplier's recommended disposal procedures for leaking containers.q Do not modify, alter, or repair containers and valves. Only the supplier should carry outthese tasks.Valvesq Ensure that cylinders have valve protection hoods in place when not connected to asystem.q Do not lift a cylinder by its valve protection hood. The hood is not designed to carry theweight of a cylinder.q Till possible, open valves by applying a steady force to a 200 mm (8 in.) wrench.q If the valve is very difficult to open, loosen the packing nut slightly. Tighten the packingnut after the valve is opened or closed.Repair and maintenanceq Employers are responsible for providing written preventive maintenance procedures andwritten emergency procedures to any person who works on a chlorine system.q Workers should be familiar with these procedures before carrying out repairs ormaintenance on the chlorine system.q Qualified workers must supervise the cleaning and repairing of chlorine systems.q The chlorine system must be shut off before cleaning or repairing it, and all piping andother equipment must be thoroughly purged with dry air or nitrogen. Vacuum systems canbe purged by drawing the remaining chlorine into the process. Do not weld any part of achlorine system until it has been purged with dry air or nitrogen.q After repair or maintenance work and before using the system, the pressurized part of thechlorine system must be pressurized to 150 psi with dry air or nitrogen and tested for leaksby applying soap solution to the outside of joints. Once detectable leaks are repaired, the

system must be retested.MoistureChlorine reacts with moisture to form corrosive acids. Every precaution must be taken tokeep chlorine and chlorine equipment free of moisture, including the following steps:q Close pipes, lines, valves, and containers tightly when not in use to keep moisture out of the system. Moisture causes chlorine to rupture steel pipeq Avoid contact between chlorine and any residual material that drips from the equipmentwhen pipes or lines are being dismantled before repair.q Dry pipes and lines before use by purging with dry air (air that has a dew point of at least-40C) or nitrogen.Foreign materialPipes, lines, and fittings must have all cutting oils, grease, and other foreign materialremoved from them before use. Trichloroethylene or other recommended chlorinatedsolvents may be used; however, take special precautions as required. Never usehydrocarbon or alcohol solvents for cleaning because they can react vigorously withchlorine.Linseed oil with graphite or white lead, Freshly mixed glycerin and lithargemay be used as a lubricating pipe dope for threaded joints. If Teflon tape is used, allremnants must be removed before joints are remade.HeatBecause iron and steel will ignite in chlorine at about 230C (450 - 500F), all welding orburning must only be done after the chlorine equipment is completely emptied and purged


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with dry air or nitrogen.Engineering controls (building design)specific design and ventilation requirements and guidelines for chlorine systems and storagefacilities.Chlorine enclosureConsider the following points when designing a chlorine system or storage facility:

q Containers and equipment must be located in a separate enclosure with fire-resistantfloors and walls. If possible, chlorine containers should be housed in a room separate fromthe area where the chlorination equipment is located.q Chlorine storage enclosures must be designed so that chlorine containers and equipmentare located at the lowest level. Work areas should not be located below the chlorine system.q Storage rooms with floor areas larger than 60 square meters (200 sq. ft.) must have twoor more exit doors which must open outwards and should not be self-locking to ensureaccessible escape routes.q Each room or building housing chlorine containers or equipment should have a viewingwindow at least 30 cm (12 in.) square or larger that will provide a clear view of thecontainer and distribution system.Ventilationq A suitable fan, having switch outside the room/ shed providing at least 15 air changes perhour, must ventilate the chlorine storage room.q Because chlorine gas is much heavier than air and tends to collect at floor level,ventilation fan suction must be located at or near floor level. Air inlets must be located toprovide cross-ventilation using outside air.Administrative controlsAlarm systemsq In case of a chlorine leak or emergency, all factories must have a working alarm that canbe heard and seen by workers. A continuous (24-hour) chlorine monitor must be connectedto the alarm system. The continuous monitor checks chlorine concentrations in the air andthe alarm responds if chlorine concentrations reach a certain pre-set level.q All the workers and nearby public must be made acknowledge about alarm soundingpattern and actions they are required to take.

Detector tubesSeveral systems use detector tubes to give a direct reading of the chlorine concentration.Workers must be properly trained in detector tube use and maintenance. When takingmeasurements to determine the extent and severity of a leak outside the enclosure,workers must wear appropriate respiratory protection.Personal protective equipmentControlling exposure requires strict attention to chlorine exposure limits. Appropriate eye,skin, and respiratory protection are essential. Workers must be familiar with and understandthe requirements of their employer's written exposure control program.Other Equipments required for Leak ControlEmergency kit : It must be having good no rusted condition, and must have all the requiredcomponents in order. Kit should be easily available any time.Other Equipments : Whole Body Protection Suit and gloves, Shoes, Breathing apparatus of required types, Helmets, Perfect eye protection spectacles, Dry sand bags etc. are requiredto be readily available and in usable condition.Eye protectionWhen chlorine gas is in the air, safety glasses and face shields will not protect the eyes.Workers in an area that contains a chlorine concentration that may irritate the eyes (forexample, greater than 0.5 ppm) must wear eye protection with a tight seal around the eyesor face to prevent chlorine gas entering the eyes. At this concentration, eye protection willbe worn with the required respiratory protection.Skin protection


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Emergency response workers who are controlling a serious chlorine leak must have accessto full-body protective suits.Respiratory protectionOutlines of the types of respirators available to protect workers from exposure to chlorineand the limitations of each respirator. Respirator choices must be based on the needs of each individual worksite and the requirements of the employer's written safe work

procedures.Full-face piece respirator with cartridgesA worker must wear a full-face piece respirator fitted with acid gas cartridges during anyhazardous work where there is a chance of a chlorine leak. Full-face piece respirators arealso appropriate for leak control where tests show the chlorine concentration to be less than10 ppm (IDLH level).Full-face piece respirator with canisterAlthough cartridges are preferable, a worker may use a full-face piece respirator fitted withan air-purifying canister for leak control and repair or maintenance procedures in chlorineconcentrations less than 10 ppm.Notes:1. When a worker is repairing a leak, cartridges or canisters can only be worn when thechlorine concentration is known.2. Canisters with an indicator window must be replaced when the material in the windowhas changed color. Canisters without an indicator window must be replaced after each use.In either case, canisters must never be used after the expiration date stamped on the label.Half-face piece respirator with gogglesA worker may use a half-face piece respirator with vapour-tight chemical goggles whenworking on a chlorine system where there is a chance of a small leak. This type of respiratoris permitted only when the chlorine concentration is below 5 ppm.Self-Contained Breathing Apparatus (SCBA)A worker must use an SCBA when a chlorine leak is suspected and the airborne chlorineconcentration is unknown or is measured at more than 10 ppm. A worker wearing an SCBAmust not enter a contaminated atmosphere until a second, qualified person is present, alsoequipped with an SCBA, and ready to perform a rescue. SCBA air cylinders should be refilled

every six months or after each use, whichever comes first.Escape respiratorThere are two acceptable types of escape respirators: bite-block respirators and half facepiece cartridge respirators fitted with acid gas cartridges. Bite-block respirators must beworn with nose plugs. Escape respirators may only be used for immediate evacuation of thecontaminated atmosphere.Anyone entering a chlorine room for any reason must carry an escape respirator and keep itwithin arm's reach at all times.Situation of Chlorine concentration and Respirator choice (for guidance)Routine work in chlorine room - escape respirator(If a leak occurs, the concentration will be unknown. Exit room immediately.)working on chlorine system - half-face piece respirator with tight chemical goggles, or full-face piece respirator (If a leak occurs, the concentration will be unknown. Exit roomimmediately.)up to 5 ppm o half-face piece respirator with tight chemical goggles, or o full-face piecerespirator greater than 5 ppm up to 10 ppm full-face piece respirator greater than 10 ppmSCBA, when leak occurs, or to enter space (having Chlorine in atmosphere repair) unknownppm-- always assume to be IDLH level SCBAPerson-check telephoneEmployers must establish a check system to ensure the continued well-being of workerswho are working alone or at an isolated worksite. Where visual checks are not possible, thecheck system may require a radio or telephone. Workers who will need to use such a


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system must be trained in the written procedure.Emergency equipmentEmergency equipment includes eye wash and shower facilities, first aid kits, and containerrepair kits. Workers must have immediate access to each of these items and must knowhow to use them in case of emergency.First aid in various injuries:

Chlorine inhalationSomeone who has inhaled chlorine may be unconscious, and may have difficulty breathingor may have stopped breathing completely. Assess the victim's breathing: If breathing has stopped, begin artificial respiration and continue until the victim resumesbreathing. Pocket masks are recommended for artificial respiration, although the mouth-to-mouth method may also be used. If the victim is having difficulty breathing (for example, gasping or coughing), place thevictim in the most comfortable position, usually semi-sitting. If an oxygen therapy unit and trained personnel are available, administer oxygen at a 10-litre flow. Ensure that the victim is transported to hospital in case the victim suffers a delayedreaction in the form of pulmonary edema. Any physical exertion, excitement, orapprehension increases the chance and severity of a delayed reaction. Keep the victimwarm and completely at rest. Reassure the victim while waiting for assistance andtransportation to hospital.Unconscious patientsAs soon as they resume breathing, always place unconscious patients in the drainageposition (on their side, so fluids can drain from the mouth and airways). Never give anunconscious patient anything by mouth.Skin contactSkin contact with chlorine can result in severe burns. Before attempting to flush a victim'scontaminated skin, make sure the victim is breathing properly. Follow these steps: Assessthe victim's breathing and follow the procedure as indicated for inhalation.q As soon as the victim resumes breathing, flush the victim's contaminated skin andclothing with large amounts of water for 30 minutes.

q Remove all contaminated clothing while flushing.q Continue flushing until all traces of chlorine have been removed.q Dress obvious burns with sterile gauze and bandage them loosely. Apply insulated coldpacks to help reduce pain.q Get the victim to hospital.

Eye contact Eye contact with chlorine (liquid or gas) for even a short period can cause permanentdisability. Flushing must begin within 10 seconds. Follow these steps:1. Flush the eyes immediately with large amounts of running water (preferably lukewarm)for 30 minutes. Hold the eyelids forcibly apart to ensure full flushing of the eyes andeyelids.2. After flushing has removed all traces of chlorine, cover both eyes with moistened sterilegauze pads and bandage, enough to keep light out.3. Apply insulated cold packs to help reduce pain.4. Get the victim to hospital.Notes:1. Do not attempt to neutralize the chlorine with other chemicals. 2. Do not applyoils, ointments, or medications to the eyes.

What to Do When a Person is Exposed to Chlorine - q Remove the exposed person(s) to fresh air.


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q Call immediately company safety personnel.q If the victim is not breathing, begin artificial respiration. If the victim is breathing, place ina seated position or lying down with the head and upper body in an upright position.Encourage slow, deep, regular breaths. Have a health professional administer oxygen.q Keep the person warm and quiet.q Persons with serious symptoms may need to be hospitalized.

Decontamination Procedures -q Remove soaked clothing from the victim and double-bag it immediately.q Flush exposed skin/hair with water for 2-3 minutes; wash twice with mild soap and rinsethoroughly with water.q Flush exposed or irritated eyes with water/saline for 15-30 minutes. If the person iswearing contact lenses, try to remove them.What to Do in Case of an Emergency Chlorine Release -q Follow the procedures laid down in On Site Emergency Plan.q All persons not engaged in stopping the leak should leave the affected area until normaloperating conditions are restored. If the amount of chlorine released is excessive, thenspecial steps should be taken to warn all persons in the path of the fumes.q Small leaks may be readily located by the use of a squeeze bottle containing ammoniawater near the suspected leak (avoid squeezing liquid on the leak). If the container orequipment is leaking, then dense white fumes of ammonium chloride will indicate the exactlocation of the leak. Approach the leak from the upwind side and since chlorine gas isheavier than air, keep the head above the leak.q If the leak is in the chlorinating or unloading equipment, the nearest control valvebetween the chlorine container and the leak should be immediately closed and the chlorinelines emptied to the process. Leaks around a container valve stem can generally be stoppedby tightening the packing nut.q Use emergency kit to stop the leak but only by persons wearing foolproof PPEq Far as possible use the Chlorine in process using secondary valve of the kit.q If leakage is not controllable by kit use FRP HOOD and scrub the Chlorine usingneutralizing arrangements.Water should never be applied around a chlorine leak or onto a spill of liquid chlorine..

Apart from the corrosive action caused by the addition of water, the heat supplied by evencold water may cause the liquid in the container or on the ground to vaporize faster. Sincethe pressure within a container governs the rate of discharge, a leak can be reduced bydrawing off gaseous chlorine to the process as rapidly as possible. If the consuming processcannot take the gas rapidly enough, then the chlorine may be absorbed in a solution of sodium hydroxide, soda ash or hydrated lime.q Notify trained personnel immediately, such as the company's safety team and the localfire department. Untrained persons or those without proper personal protective equipmentmust not enter areas with high concentrations of chlorine.q Evacuate people from the hazardous area for at least 500 feet in all directions and havethem stay upwind of the chlorine release. They should be sheltered in a building with doorsand windows shut and air conditioners turned off.q Stop/control the source of exposure. If the exposure is from a leaking cylinder, take itoutdoors or to an open area until completely drained and contents have evaporated.q Ventilate potentially explosive atmospheres by opening windows.q Keep combustibles such as wood, paper, and oil, away from the leak.q Remove all sources of heat and ignition.q Refer to Material Safety Data Sheet (MSDS) for more information.

Conclusive Suggestions Based On Experience During Inspections Accidents in factories using Chlorine are found to be, because of the following reasons whichare avoidable by sincere efforts.


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Physical reasons a. Improper storage place and nonscientific unsafe pattern of storage.b. Insufficient and poorly maintained plant, workplace and equipments including PPE.c. Not using standard materials like pipes, clamps, spanners etc.d. Insufficient work force hence Chlorine related processes poorly supervised.e. Untrained or partially trained workers ( many times ever changing contract workers)

engaged in the process.f. No sincerity towards rehearsal of On Site Emergency Plan and Emergency ControlProcedures.Attitudinal Reasonsg. Implementation of safety laws as a legal must, just for protection against authorities.Hence continuity in implementation not maintained.h. An attitude to save money against safety compliance.i. A wrong confidence and belief - No accident took place in past so factory is safe.

j. Poor understanding regarding benefits of implementation of safety laws.k. Willful ignorance and violation of safety laws.

Some Tips

a. Have a positive attitude for safety, time has changed you must change accordingly foryour own at least.b. Spend sufficient to implementing on safety related requirements- i t will prove to be yourwise investment.c. Never allow hazardous work in absence of insufficient trained staff or with untrained workforce.d. Have best of safety equipments and maintain it too, arrange for it's regular and randomsupervision.e. Share your experiences and difficulties with near by Chlorine user factory managements.If possible form a Chlorine users club for local area pocket or estate.f. Introduce some incentive scheme for motivation of safety related activities and attitude of employees.

Safety of Chlorine Handling

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