PREAMBLE (NOT PART OF THE STANDARD)
In order to promote public education and public safety, equal justice for all,
a better informed citizenry, the rule of law, world trade and world peace,
this legal document is hereby made available on a noncommercial basis, as it
is the right of all humans to know and speak the laws that govern them.
END OF PREAMBLE (NOT PART OF THE STANDARD)
IS : 4263-1967
(Reaffirmed 1995)
Indian Standard
CODE OF SAFETY FOR CHLORINE
(Seventh Reprint OCTOBER 1997)
UDC 661.41 : 614.8
© Copyright 1967
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
Gr 5
November 1967
i
ii
iii
iv
1
2
3
4
Indian Standard
CODE OF SAFETY FOR CHLORINE
Chemical Hazards Sectional Committee, CDC 18
| Chairman |
Representing |
| Shri N. S. Mankiker |
Directorate General of Factory Advice Service &
Labour Institutes (Ministry of Labour, Employment & Rehabilitation),
Bombay |
| Members |
|
| Shri J. D. Adhia |
Hindustan Organic Chemicals Ltd, Bombay |
| Shri S. M. Machiraju (Alternate) |
| Shri S. K. Borkar |
Directorate General of Health Services (Ministry of Health), New Delhi |
| shri P. S. Ramachandran (Alternate) |
| Shri J. M. Dave |
Central Public Health Engineering Research Institute (CSIR), Nagpur |
| Deputy Director, Traffic (General) |
Railway Board (Ministry of Railways), New Delhi |
| Shri J. M. Guha |
Ministry of Petroleum and Chemicals |
| Dr G. Jayarama Rao (Alternate) |
| Dr Jagdish Shankar |
Atomic Energy Establishment Trombay, Bombay |
| Shri Joginder Singh |
Directorate General of Technical Development, New Delhi |
| Shri S. N. Lahiri |
Department of Explosives (Ministry of Works and Housing) |
| Shri S. C. Roy (Alternate) |
| Shri C. C. Maniar |
Indian Chemical Manufacturers’ Association, Bombay |
| Dr V. C. Mankodi |
Hindustan Steel Ltd, Ranchi |
| Dr B. N. Chakravarty (Alternate) |
| Shri M. N. Khanna (Alternate) |
| Dr C. N. K. Murthy |
Ministry of Defence (DGI) |
| Shri R. S. Agarwal (Alternate) |
| Shri Narendra Singh |
Ministry of Defence (R & D) |
| Dr K. J. Balakrishna (Alternate) |
| Representative |
Indian Institute of Petroleum (CSIR), Dehra Dun |
| Shri M. Venugopal |
The Western India Match Company Ltd, Bombay |
| Dr Sadgopal, Director (Chem) |
Director General, ISI (Ex-officio Member) |
Secretary
Dr A. K. Bhattacharya
Deputy Director (Chem), ISI
(Continued on page 2)
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
1
(
Continued from page 1)
Industrial Chemical Hazards Subcommittee, CDC 18 : 4
| Convener |
Representing |
| Shri S. R. Bhise |
Directorate General of Factory Advice Service &
Labour Institutes (Ministry of Labour, Employment & Rehabilitation),
Bombay |
| Members |
|
| Shri J. D. Adhia |
Hindustan Organic Chemicals Ltd, Bombay |
| Shri S. M. Machiraju (Alternate) |
| Shri J. M. Dave |
Central Public Health Engineering Research Institute (CSIR), Nagpur |
| Deputy Director, Traffic (General) |
Railway Board (Ministry of Railways) |
| Dr R. M. Desai |
Indian Chemical Manufacturers’ Association, Bombay |
| Shri O. P. Gupta |
Directorate General of Ordnance Factories (Ministry of Defence) |
| Shri S. C. Das Gupta (Alternate) |
| Shri S. Jagannathan |
Esso Standard Eastern Inc, Bombay |
| Shri K. V. Vijayaraghavan (Alternate) |
| Shri Joginder Singh |
Directorate General of Technical Development, New Delhi |
| Shri G. A. Kulkarni |
Amar Dye Chem Ltd, Bombay |
| Shri S. N. Lahiri |
Department of Explosives (Ministry of Works and Housing) |
| Shri S. C. Roy (Alternate) |
| Dr U. C. Patel |
Union Carbide India Limited, Calcutta |
| Shri K. C. Raghavan |
D. Waldie and Company Limited, Calcutta |
| Dr R. Chatterjee (Alternate) |
| Shri M. L. Seth |
The D. C. M. Chemical Works, New Delhi |
| Shri L. R. Gautam (Alternate) |
Panel for Drafting Safety Codes for Hazardous Chemicals, CDC 18 : 4 : 1
| Convener |
|
| Shri M. L. Seth |
The D. C. M. Chemical Works, New Delhi |
| Members |
|
| Shri L. R. Gautam (Alternate to Shri M. L. Seth) |
| Shri S. K. Barat |
Fertilizer Corporation of India Ltd, Sindri Unit |
| Shri B. N. Chakravarty |
Hindustan Steel Ltd, Ranchi |
| Dr K. V. Viswanathan Nayar |
Fertilizers and Chemicals Travancore Ltd, Udyog Mandal P.O., Kerala State |
2
Indian Standard
CODE OF SAFETY FOR CHLORINE
0. FOREWORD
0.1
This Indian Standard was adopted by the Indian Standards Institution
on 14 June 1967, after the draft finalized by the Chemical Hazards
Sectional Committee had been approved by the Chemical Division Council.
0.2
One of the greatest hazards associated with the use of chlorine is
that, in becoming a familiar part of a process, it is often forgotten
that it is potentially dangerous. The shipment of liquid chlorine in
bulk from manufacturer to consumer involves various handling operations,
in which the principal risks are common. These are attributable to its
toxicolgical character, physical properties, and chemical reactivity.
0.3
It is important that personnel, engaged in a, chlorine plant or in
any activity involving handling of chlorine, should understand the
hazardous properties of chlorine and should have a good grasp of the
basis of preventive measures. This will make them more conscious about
safety which would not be achieved if they are trained to follow certain
instructions mechanically.
0.4
In India, chlorine is deemed to be an explosive, when contained in
any metal container in a compressed or liquefied state, within the
meaning of the Indian Explosives Act, 1884. The filling, possession,
transport and importation is governed by the Gas Cylinder Rules, 2004.
1. SCOPE
1.1
This standard prescribes a code of safety concerning hazards relating
to chlorine. It describes properties and essential information for the
safe handling and use of chlorine.
2. TERMINOLOGY
2.1
For the purpose of this standard, the definitions given in IS : 4155-1966* and IS : 4167-1966†, shall apply.
*Glossary of terms relating to chemicals and radiation hazards and hazards chemicals.
†Glossary of terms relating to air pollution.
3
3. PROPERTIES OF CHLORINE
3.1 General Properties
| a) |
CAS Number |
: |
7782-50-5 |
| b) |
UN Number |
: |
1017 |
| c) |
UN Class |
: |
2 |
| d) |
Hazchem Code |
: |
2XE |
| e) |
NFPA Hazard Index |
|
1) Health |
: |
3 |
| 2) Flammability |
: |
0 |
| 3) Reactivity |
: |
0 |
3.2 Physical Properties
3.2.1
Some of the important physical properties of chlorine are:
- Physical State—gas as well as liquid
- Colour—greenish yellow (gas), clear amber (liquid)
- Odour—characteristic, suffocating
- Boiling Point (Liquefying)—34.6°C (1 atm)
- Freezing (melting) point—−100.98°C (1 atm)
- Density—3.209 g/1 (1 atm; 0°C)
- Vapour Pressure—3.617 atm (0°C).
3.2.2
Liquid-Gas Volume Relationship—The weight of one volume of liquid chlorine equals the weight of 457.6 volumes of gas at 0° and 1 atm.
3.2.3
Solubility—Chlorine is soluble in alkalis and only slightly
soluble in water, approximately 1 percent at 9.4°C. Above this its
solubility decreases with rise in temperature up to the boiling point of
water at which it is completely insoluble. Below 9.4°C chlorine hydrate
known as ‘Chlorine-ice’ (Cl
2.8H
2O), may crystallise.
3.3 Chemical and Hazardous Properties
3.3.1
Flammability—Neither liquid nor gaseous chlorine is explosive
or flammable, but both react readily with many organic substances,
usually with the evolution of heat and, in some cases, resulting in
explosion. Chlorine is also capable of supporting combustion of certain
materials.
3.3.2 Reactivity
3.3.2.1 With metals
- Dry chlorine reacts with aluminium, arsenic, gold, mercury,
selenium, tellurium, tin and titanium. At certain temperatures potassium
and sodium burn in dry chlorine. Carbon steel ignites at temperatures
above 250°C.
- Dry chlorine, both gaseous and liquid, may be handled safely in
equipment fabricated from iron, steel, stainless steels, Hastelloy ‘C’,
Monel, nickel, copper, brass, silver, lead and platinum below 110°C (at
temperatures above 65°C, chlorine reacts with steel at an accelerated
rate). However, this temperature is considerably lower if the metal or
alloy is in finely divided, sponge, or wire form.
- Titanium, platinum, gold and silver are resistant to wet chlorine.
Titanium is resistant to both wet and dry chlorine at temperature below
14°C. Moist chlorine readily reacts with mercury. At low pressure, wet
chlorine may be handled in equipment made of glass, porcelain, and
chemical stoneware. 4
3.3.2.2
With other elements—Chlorine reacts with most elements under
specified conditions. Mixtures of chlorine and hydrogen composed of more
than 5 percent of either component may react with explosive violence.
It reacts with ammonia, alkalis and alkaline earth metal hydroxides.
3.3.2.3
With inorganic compounds—Chlorine has great affinity for
hydrogen and as such, removes hydrogen from some inorganic compounds to
form hydrochloric acid. It reacts with ammonia and ammonium compounds to
form various mixtures of chloramines and under proper conditions
nitrogen trichloride which is explosive. Chlorine reacts readily with
lime and caustic soda to form hypochlorites which are well-known
bleaching agents. Chlorine reacts with moisture to liberate nascent
oxygen and form hydrochloric acid. The following chemical reactions take
place between chlorine and lime or caustic soda:
2Ca(OH)2 + 2C12 + 2H2O = Ca(OCl)2.4H2O + CaCl2
2CaO + 2Cl2 + 4H2O = Ca(OCl)2.4H2O + CaCl2
2NaOH + Cl2 = NaOCl + NaCl + H2O
These reactions are important because lime and caustic soda solutions are used for handling chlorine leaks.
3.3.2.4
With organic compounds—Chlorine reacts with organic compounds
to form chlorinated derivatives and hydrogen chloride. Some of these
reactions, particularly those with hydrocarbons, alcohols and ethers may
become explosive. Gaseous chlorine, wet or dry, may be used with hard
rubber equipment at normal temperatures and pressures. However, neither
soft nor hard rubber can be used with liquid chlorine.
4. HAZARDS ASSOCIATED WITH CHLORINE
4.1 Health Hazards
4.1.1
General—Chlorine gas is primarily a respiratory irritant. The
characteristic penetrating odour of chlorine gas usually gives warning
of its presence. At higher concentration it is visible as greenish
yellow gas. The effect of chlorine may become more severe for upto 36
hours of exposure.
4.1.2
Acute Local—Short-duration exposures of skin to high
concentrations of chlorine gas is not much irritating or corrosive. But
this effect is perceptible only when prolonged exposure is tolerated by
the use of respiratory protection. Splashes of liquid chlorine on the
eyes, skin and clothing, may cause immediate irritation and chemical
burns, and severe damage to body tissues.
5
4.1.3
Acute, Systemic—Chlorine gas is extremely irritating to the
mucous memberanes, the eyes and the respiratory tract. If the duration
of exposure or the concentration of chlorine-is excessive, it will cause
restlessness, throat irritation, sneezing and copious salivation. In
extreme cases, lung tissues may be attacked resulting in pulmonary
edema. Inhal lowest published toxic concentration TC
L0 is 15
ppm and Inhal lowest published lethal concentration is 430 ppm. The
physiological effects of various concentrations of chlorine gas are
shown in Table 1.
Table 1 Effect of Chlorine at Various Concentrations
(clause 4.1.3)
| SI No. |
Effects |
Concentration of Chlorine Gas in Air, ppm |
| (1) |
(2) |
(3) |
| i) |
TLV-TWA(ACGIH) |
0.5 |
| ii) |
STEL |
1 |
| vi) |
Least amount for detectable odour |
3.5 |
| iv) |
Threshold of irritation |
4.0 |
| v) |
Noxiousness, impossible to breathe several minutes |
5.0 |
| vi) |
Concentration causing immediate irritation of throat |
15 |
| vii) |
Concentration causing cough |
30.2 |
| viii) |
Concentration dangerous in 30 minutes to 1 h |
40-60 |
| ix) |
Concentration dangerous for even short exposure |
50 |
| x) |
Fatal even if the exposure is brief |
1000 |
4.1.3.1
Effect of liquid chlorine by absorption through skin, lungs, or
intestinal canal is unknown/but when exposed to normal atmospheric
pressure and temperature it vaporises to gas which will produce the
effects described in
4.1.2 and
4.1.3.
4.1.4
Chronic (Local and Systemic)—Chlorine gas produces no known
cumulative effects. A concentration of 1 ppm of chlorine gas may produce
slight symptoms after several hours exposure, but careful examination
of workers exposed daily to detectable concentrations reportedly has
shown no chronic systemic effects. Local chronic effects have not been
clinically demonstrated. Sensitization has not been a problem with
chlorine. It has been observed that prolonged exposure to atmospheric
chlorine concentration of 5 ppm results in disease of bronchi and a
predeposition of tuberculosis while lung studies have shown that
concentration of 0.8 to 1 ppm cause permanent, although moderate
reduction in pulmonary function. Acne is not unusual in persons exposed
for long periods of time to low concentrations of chlorine, and is
commonly known as chlorance—Tooth enamel damage may also occur.
4.1.4.1
It should be noted here that several hours exposure in the atmosphere
containing chlorine at a concentration below that which can be detected
by smell or sight may produce slight irritation. Therefore, suitable
means of leak detection should be employed for the protection of persons
continuously exposed to chlorine handling operations, especially in
confined areas. One of the most effective way of leak detection is the
use of aqueous ammonia solution, which produces white fumes in the
presence of even slight quantities of chlorine.
4.2 Explosion Hazard
Chlorine reacts spontaneously with hydrogen slowly in the dark but explosively in sunlight or at high temperatures, to
6
form hydrogen chloride. The rate of reaction in an equivalent mixture
of the two gases is reportedly increased markedly by the presence of
oxygen. This fact is of great importance during the manufacture of
chlorine by electrolysis and precautions must be taken to prevent the
mixing of hydrogen with chlorine in dangerous proportions which may
cause a serious fire and explosion. Regular analysis of chlorine for its
hydrogen content is essential. The lower explosive limit of
hydrogen-chlorine mixtures varies from 3.1 to 8.1 percent, depending on
pressure and other variables.
4.2.1
Hot chlorine gas from electrolytic cells, may sometimes crystallize as chlorine octahydrate (Cl
2.8H
2O)
due to sudden cooling and clog the pipe lines resulting in hold up of
the gas in the pipe lines and allied equipment. This will cause back
pressure inside the cells and escape of chlorine into air or into the
hydrogen chamber resulting in explosion.
4.2.2
Since liquid chlorine increases considerably in volume when
evaporated, hydrostatic rupture in containers, pipe lines and other
equipments may occur due to build up of excessive pressure.
Particularly, the danger due to pressure build up in a heated cylinder
leading to an explosion is to be noted.
4.3 Fire Hazard
Though the fire hazard, attributable to chlorine, is only moderate,
it may react to cause fires or explosions upon contact with turpentine,
ether, ammonia gas, illuminating gas, hydrocarbons, hydrogen, powdered
metals, saw dust and phosphorus.
5. STORAGE AND HANDLING
5.1 Storage
5.1.1
Cylinders should be stored in an upright position. They should be
secured to prevent from falling over. Full and empty cylinders should
not be stored together. Ton containers should be stored on their sides.
They should not be stacked or racked more than one high.
5.1.2
Storage areas should be remote from, elevators gangways or
ventilating systems because, in the event of a chlorine leak, dangerous
concentrations of chlorine may spread rapidly.
5.1.3
The storage area should be separate from that in. which other
compressed gas containers are stored, and should contain no turpentine,
ether, anhydrous ammonia, finely divided metals or other Inflammable,
Material. The storage area should be dry, well-ventilated, clean of
trash, and protected from external heat sources (steam pipes, etc).
Sub-surface areas should be avoided for storing chlorine cylinders.
5.1.4
The valves on cylinders and ton containers should be protected by a
stout metal cap securely attached to the cylinder body. This cap should
7
always be kept in place on all containers in storage and at all times except during evacuation of chlorine.
5.2 Handling
5.2.1
Cylinders should never be lifted by means of the metal cap, nor
should rope slings, chains or magnetic devices be used. Unloading
platforms should preferably be at truck or car-bed level. The ton
container should be handled with a suitable cradle with chain slings in
combination with a hoist or crane having at least 2 metric tonnes
capacity.
5.2.2
Cylinders and ton containers being trucked should be carefully
checked, clamped, or otherwise suitably supported to prevent shifting
and rolling. They should not be permitted to drop, and no object should
be allowed to strike them with force. They should not project beyond the
sides or ends of the vehicles in which they are transported.
5.2.3
Using Chlorine From Cylinders—Cylinders normally should be
emptied in the gas phase, standing secured in an upright position. If it
is necessary to empty them in the liquid phase, they should be
partially inverted and clamped securely on a rack set at an angle of
above 60° to the horizontal. Connection of containers discharging liquid
to a manifold is not recommended.
5.2.3.1
Ton-containers set in a horizontal position, with the valves in a
vertical plane, deliver gas from the upper valve and liquid from the
lower valve. When emptied in the liquid phase, a vaporizer should
normally be used.
5.2.4
The flow of chlorine-gas from any chlorine container depends on the
internal pressure which in turn depends on the temperature of the liquid
chlorine. Discharge rates may, however, be increased by forced
circulation of room-temperature air around the container.
5.2.4.1
If the gas discharge rate from a single container will not meet
demand requirements, two or more may be connected to a manifold and
discharged simultaneously, or a vaporizer may be used. When discharging
through a manifold, care shall be taken that all containers are at the
same temperature, particularly when connecting a new container to the
manifold. If there is a difference in the temperature of the liquid
chlorine, it will be transferred by distillation from the warm to the
cool container, and the cooler container may become completely filled
with liquid. If this should occur and the container valve remains
closed, hydrostatic pressure may cause bursting. For this reason, extra
precautions shall be observed when closing valves of containers
connected to a manifold. Connection of cylinders or ton containers
discharging liquid chlorine to a manifold is not recommended.
5.2.5
A flexible connection between the container and the piping should be
used; annealed copper tubing (9.5 mm outside diameter × 0.889 mm
8
wall), suitable for 35.2 kg/cm
2 service is recommended. A
clamp and adapter connector is preferred; if a union connector is used,
the threads on the connector shall match the valve outlet thread. (Valve
outlet threads are straight threads, not standard taper pipe threads.) A
new gasket (lead) should be used when making a connection.
5.2.6
Valves should be opened counter-clockwise with a 9.5 mm square-box
wrench not over 152 mm long. If the valve is difficult to open, the
packing nut may be struck with the heel of the hand, no other implements
ought to be used.
5.2.7
When chlorine is being absorbed in a liquid, proper precautions shall
be taken to prevent suck-back of the liquid into the container when it
becomes empty (due to a partial vacuum created) ; a barometric leg or
vacuum breaking device or both should be used.
6. PACKING AND LABELLING
6.0 General
The packing, labelling, handling, and transportation of chlorine gas,
when contained in a metal container in a compressed or liquefied state
is governed by the Gas Cylinder Rules, 2004.
6.1 Packing
6.1.1
Hydraulic Test—No cylinder should be filled with chlorine gas
unless such cylinder has been, subjected by the person filling it to the
hydraulic test specified in Schedule I of the Gas Cylinder Rules, 2004,
within the preceding 2 years and has passed that test. Any cylinder
which fails to pass the hydraulic test or which for any other reason is
found to be unsafe for use should be destroyed or rendered useless by
cutting holes in it.
6.1.2
Examination Prior to Filling of Cylinder—Every cylinder should
be completely emptied, thoroughly cleaned and dried, before it is
passed for filling. It should also be examined externally and so far as
practicable internally, for surface defects, corrosion and foreign
matter.
6.1.3
Filling Ratios and Working Pressure—Cylinders should not be
filled with liquid chlorine in excess of the filling ratio of 1 : 19 as
specified in Schedule II. of Gas Cylinder Rules, 2004.
6.1.3.1
The working or internal pressure in the cylinder charged with chlorine should not exceed 19.9 kg/cm
2 gauge in tropical climates at a maximum of 65°C.
6.2 Marking and Labelling of Cylinders
6.2.1
Every cylinder should be legibly marked with the label as given in
Fig. 2 of IS : 1260-1958* and the warning in the following terms should
be
*Code of symbols for labelling of dangerous goods.
9
printed in the lower half of the label:
Warning ! CHLORINE !
- Do not change the colour of this cylinder.
- This cylinder may not be filled with any gas other than chlorine.
- This cylinder should be kept cool. It should not be placed near a stove or any other source of heat, nor be exposed to the sun.
- No oil or similar lubricant should be used on the valves or other fittings of this cylinder.
- This cylinder should not be stored with any inflammable or explosive material.
7. GENERAL PREVENTIVE MEASURES
7.0
The fundamental steps for safe working conditions in a plant or area where chlorine is produced, stored or processed are:
- designing of layout of area with due consideration for adequate natural or mechanical ventilation,
- use of properly selected material for construction of plant and equipment for handling of chlorine,
- preventive maintenance of all equipment in proper working condition, and
- availability and use of adequate and suitable personal protective equipment at all times.
7.1 Employee Selection and Training
7.1.1
Employee Selection—Chlorine is particularly irritating to
persons afflicted with asthma, certain types of bronchitis, other
chronic lung conditions, and irritations of the upper respiratory tract;
such persons should not be employed where exposures to chlorine gas
might occur. Pre-placement medical examination including a chest X-ray
is recommended for all new entrants and follow-up medical examinations
at suitable intervals for all workers handling chlorine.
7.1.2
Employee Training—Training classes for both new and old
employees should be conducted periodically to keep them conscious and
informed of the hazards. There should be periodic drill and instruction
regarding location, purpose and use of personal protective equipment,
safety showers, eye fountains, first aid kits, etc. They should be
cautioned to prevent leaks, avoid inhalation of gas and direct contact
with the liquid. They, should be told to report to proper authorities
immediately in case of an equipmen failure.
10
7.1.2.1
All workers should be instructed and trained to adopt preventive
measures in case of emergency. Such training should include knowledge of
emergency, fire fighting equipment, fire alarms, crash shut-down
procedures for valves and switches, steps to be taken before starting
repairs anywhere in the plant, use of personal protective equipment and
first-aid. Regular and surprise drills for the above should be conducted
to improve further the training in preventive and emergency aspects.
7.2 Eye Protection
Eye protection devices should always be worn in a chemical plant. If
there is danger of contact with liquid chlorine, it is essential to wear
a gas mask with a full facepiece.
7.3 Respiratory Protection
A suitable gas mask should be available to every employee involved
with chlorine handling. Respiratory protective equipment should be
carefully maintained and kept in clean, dry, light-proof cabinets
properly protected by paraffined paper or polyethylene bags. Cleaning
and inspection by competent person is generally necessary after each
occasion on which the apparatus is used and should, in any case, take
place at least once a month. Equipment used by more than one person
should be sterilized after each use. A defective or. inoperable mask is
worse than none at all.
7.3.1
So far as it is possible and consistent with efficient protection and
use, the protective equipment should be comfortable to work with.
7.3.2
No person wearing a respirator should enter a chlorine contaminated
area unless attended to by an observer who can rescue him in the event
of respirator failure or other emergencies.
7.3.3
Respiratory Protective Devices—have moulded flexible
facepieces with transparent windows which vary in size and shape. Eye
protection is imperative due to the irritating nature of moist chlorine
gas or liquid chlorine splashes. Provision for exhaust air is
accomplished by various types of valving devices which remain tightly
closed during the intake cycle of breathing. Connections between the
facepiece and other parts of the apparatus utilize a flexible tube,
which permits free head movement. This tubing shall be visually
inspected and tested for performance at frequent intervals. If leaks in
the facepiece, tube, or tube connections cannot be eliminated by
tightening the head straps, the complete facepiece and attached flexible
tube shall be replaced.
7.3.4
It is equipped with a cylinder of respirable air carried on the body,
and is suitable for high concentrations of chlorine in an
oxygen-deficient atmosphere and is preferred means of respiratory
protection. Such apparatus operates for a specified length of time.
7.3.5
Industrial Canister-Type Masks—It is equipped with a chlorine or all-purpose canister and is suitable for moderate concentrations of chlorine,
11
provided sufficient oxygen is present. The mask should be used for a
relatively short exposure period only. It may not be suitable for use in
an emergency. For example, the rupture of a chlorine container
coincident with oxygen-consuming fire would clearly indicate the use of a
self-contained or supplied-air protective device, since, at that time,
the actual chlorine concentration may exceed the safe 1-percent limit
and the oxygen content may be less than 16 percent by volume. Under this
condition suffocation is likely to result.
7.3.5.1
The canister removes contaminants during inhalation but does not
supply oxygen. The wearer must leave the contaminated area immediately
on detecting the odour of chlorine or on experiencing dizziness or
difficulty in breathing; these are indications that the mask is not
functioning properly, that the chlorine concentration is too high, or
that sufficient oxygen is not available.
7.3.5.2
Unless the presence of other gases require the use of an all purpose
canister, the chlorine canister should be used. The service life of a
canister depends on the size of the unit, the chlorine concentration and
humidity of the atmosphere to which it is exposed, and the rate of
breathing. It usually varies from 15 minutes or less at high
concentration up to several hours at very low concentrations. Canisters
installed in the mask proper with seals broken to render the unit
immediately available, do not retain their chlorine-absorptive capacity
and shall be replaced immediately after use or within 1 year in any
case.
7.3.5.3
Spare canisters should be stored in a cool, dry, accessible place,
with seals intact, and dated so that rotation of new supplies is
possible.
7.3.5.4
Exceeding manufacturers recommended limits on maximum non-use shelf
life might be hazardous. Regular replacement of over-age canisters, even
though unused, is recommended. Canisters should be periodically checked
for their efficiency.
7.3.6
Positive Pressure (Blower) Hose Mask—It is equipped with air
supplied through a hose from a remote blower and is suitable for high
concentrations of chlorine provided conditions will permit safe escape
if the air supply fails. This device is suitable in any atmosphere,
regardless of the degree of contamination or oxygen deficiency, provided
that clean, breathable air can be reached. This device is of the
continuous flow type.
7.3.7
Demand-Type Hose Mask—It supplies air to the facepiece (at a
rate governed by breathing) of the user only when he inhales. Air supply
for this device may be full-sized compressed air ^cylinders or a
compressor. As for continuous flow type units, the air supply must be
suitable for respiration.
7.3.8
Combination units are available which consist of a self-contained
demand air unit with a reinforced, high-pressure hose through which air
is supplied to the demand regulator from remote air cylinders or a
compressor. In the event that escape is not possible through the path of
entry, the air hose
12
may be disconnected and escape made using air supplied by the demand air unit on the user’s back.
7.3.9
The information given above should be abstracted, and put into a form
which is not only suitable for instant use in the event of emergency,
but which may also be used as the basis for first-aid drill. Regular
rehearsals, which include the entire testing procedure and wearing of
the equipment, will help to save the life of an employee faced with an
emergency.
7.3.10
Prevention From Long-Term Effects—The danger from long-term
effects may be minimized by maintaining careful medical supervision of
those exposed to the hazard, removing from contact anyone who shows
early symptoms of being affected, and by excluding anyone who may be
expected to show undue sensitivity by reason of existing bodily defect
or disease.
7.3.11
Containers, piping and equipment should be checked for leaks daily.
If a leak is detected it should be reported and immediate steps taken to
correct the conditions.
8. EMERGENCY MEASURES
8.0 General
Wherever chlorine is handled a potential risk is involved and a
serious, emergency might suddenly and unexpectedly occur. Emergency
situations should be anticipated, plans established and persons trained
to counteract them.
8.1 Handling Leaks
Chlorine leaks always get worse unless they are corrected promptly.
Chlorine leaks should be investigated by authorized, trained personnel
equipped with suitable gas masks. If the leak is extensive an effort
should be made to warn all persons in the path of the gas. Chlorine is
heavier than air; therefore persons should be instructed to keep above
and upwind of the leak.
8.1.1
Water shall never be used on a chlorine leak as it always makes the
leak worse due to the corrosive effect. In addition, heat supplied by
even the coldest water to a leaking container causes liquid chlorine to
evaporate faster. A leaking container, shall not be immersed or thrown
into a body of water as the leak will be aggravated due to the corrosive
effect and the container may float when partially full, allowing gas
evolution and dispersion at the surface.
8.1.2
Equipment and Piping Leaks—If a leak occurs in equipment in
which chlorine is being used, the supply of chlorine shall be shut off
and chlorine which is under pressure at the leak shall be disposed off
safely.
8.1.2.1
Leaks around valve stems usually may be stopped by tightening the
packing nut or gland. If this does not stop the leak, the container
valve shall be closed and the chlorine, which is under pressure in the
outlet piping, shall, be disposed off. If a container valve does not
shut off tight, the outlet
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cap or plug should be applied. In case of a valve leak on a
ton-container, the container shall be rolled so that the valves are in a
vertical plane with the leaking valve on top;
this is important.
8.1.2.2
If practical, the pressure in the container should be reduced by
removing the chlorine as gas (not as liquid) to process or a disposal
system. In some cases it may be desirable to move the container to an
isolated spot where it will do the least harm.
8.1.3
In case of chlorine leaks, while seeking an escape, or while
respiratory equipment is being secured and adjusted, short, shallow
breaths should be taken and eyes should be closed as much as possible.
It is important to keep above and to the windward side of escaping
chlorine gas. All exhaust mechanisms should be turned on immediately.
The leaks should be investigated at once by authorized, trained
personnel equipped with suitable respiratory protection. All other
persons should be kept away from the affected area, until the cause of
the leak is discovered and the difficulty corrected. Respiratory
protective devices should be located outside the probable area of
contamination so that it will be possible to reach them in emergency.
8.1.4
Leaks in Transit—If a chlorine leak develops in transit in a
populated area and if the magnitude of the leakage is minor, and no
emergency kits are available, excessive quantities of lime should be
used to arrest leaking chlorine. If the leakage is extensive, it is
advisable, to keep the transporting vehicle moving until open country is
reached in order to minimize the hazards. Appropriate emergency
measure, as given above, should then be taken as quickly as possible.
8.2 Alkali Absorption
As a regular part of chlorine storage and use, provisions shall be
made for emergency disposal of chlorine from leaking cylinders or
ton-containers. Chlorine may be absorbed in solutions of caustic soda or
soda ash, or in agitated hydrated-lime slurries. Caustic soda is
recommended as it absorbs chlorine more readily. The proportions of
alkali and water recommended for this purpose are given below:
| Chlorine Container Capacity |
Caustic Soda and Water |
Soda Ash and Water |
Hydrated Lime and Water |
| kg |
Weight kg |
Volume 1 |
Weight kg |
Volume 1 |
Weight kg |
Volume 1 |
| 45 |
58 |
182 |
136 |
450 |
58 |
566 |
| 68 |
90 |
270 |
220 |
680 |
82 |
815 |
| 900 |
1 160 |
3 680 |
2 720 |
9 050 |
1 160 |
11 350 |
8.2.1
A suitable tank to hold the solution should be provided in a
convenient location. Chlorine gas should be passed into, the solution
through
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an iron pipe or rubber hose properly weighted to hold it under the. surface; the container should not be immersed.
8.3 Emergency Kits
The majority of chlorine suppliers have emergency kits and skilled
technicians to use them. These kits may be used to stop most of the
leaks in a chlorine cylinder, ton container, etc, and may usually be
delivered to consumer plants within a few hours in an emergency.
However, it is advisable for the consumers to purchase kits and to train
employees in their use.
8.4 Fire
In the event of fire, chlorine containers should be moved from the
fire zone immediately. If chlorine containers cannot be moved, water
should be applied to cool them provided no chlorine is escaping.
9. FIRST-AID
9.0 General
Suitable notices should be fixed in convenient places regarding
first-aid measures. The need for speed in all first-aid shall be
impressed on everyone concerned, together with the necessity of avoiding
further shock to the patient. All employees should be informed of the
urgent necessity in their own interests of reporting immediately for
first-aid treatment, all minor accidents and also report any sickness
which may be thought to be connected with their employment. Any one
overcome by or seriously exposed to chlorine gas should be removed at
once to un-contaminated area.
9.1 Inhalation
If breathing has not ceased, the patient should be placed on his
back, with head and back elevated, and kept warm, using blankets, if
necessary. Rest is essential.
9.1.1
If breathing apparently has ceased, artificial respiration shall be
started immediately. The ‘Nielson armlift-back pressure’ method is
preferable. A physician shall be called immediately. If
oxygen-inhalation apparatus is available, oxygen should be administered
by a person authorised for such duty by a physician.
9.1.2
Stimulants rarely are necessary where adequate oxygenation is
maintained, and any such drugs for shock treatment should be given only
by a physician. Milk may be given in mild cases as a relief from throat
irritation. 1 Nothing should ever be given by mouth to an unconscious
patient.
9.2 Skin and Clothing
If liquid chlorine or chlorinated water has contaminated skin or
clothing, the emergency shower shall be used immediately. Skin areas
should be washed with large quantities of soap and water. No attempt
shall be made to neutralize chlorine with chemicals. No ointment shall
be applied for 24 hours. Contaminated clothing should be removed
immediately.
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9.3 Eyes
If eyes have been affected with liquid chlorine or high
concentrations of chlorine gas, they shall be flushed immediately with
running water for at least 15 minutes. (No attempt shall be made to
neutralize with chemicals.) Thereafter, as a first-aid measure, 2 or 3
drops of 0.5-percent solution of pontocaine or other equally effective
topical anaesthetic shall be instilled into the eyes. No oils or oily
ointment should be used unless prescribed by an eye specialist.
9.4 Ingestion
The swallowing of liquid chlorine is extremely unlikely. However, if a
person has swallowed chlorine and is conscious, he should immediately
be made to drink copious amounts of lime water, milk of magnesia, or
fresh water if the others are not readily available. Sodium bicarbonate
shall not be given. The victim may be expected to vomit spontaneously,
but no attempt should be made to induce vomiting or to use a stomach
tube. A physician shall be called immediately.
9.5 First-Aid Equipment
All employees should be given comprehensive instructions on the use
of first-aid equipment mentioned below and any other that may be
available with the authorities.
9.5.1
Properly designed emergency showers and eye baths should be provided
in convenient locations and they should be properly maintained.
9.5.2
Oxygen administration apparatus should be available in the plant’s
first-aid or ambulance room or medical dispensary. Such equipment should
be in the charge of a person knowing use of such apparatus in an
emergency. The big manufacturers and large scale consumers should train
several persons in the use of oxygen administration apparatus and make a
trained person available all the time.
9.6 Boxes or Cupboards
distinctly marked with the words ‘First-Aid’ shall be provided in
readily accessible positions. These should not contain anything except
the prescribed medical appliances and requisites. A list of contents
should be fixed to the inside of the box. A sufficient number of persons
should be imparted effective training in First-Aid.
10. EQUIPMENT CLEANING AND REPAIRS
10.1
Equipment and tank cleaning and repairs should be under the direction of thoroughly trained personnel.
10.2
Workmen should not attempt to repair chlorine equipment while it is in operation and when piping system is in service.
10.3
Welding, cutting or other work using flame or spark should not be
attempted on chlorine lines or containers until purged with steam and
then hot-air-dried. As a substitute they may be filled with carbon
dioxide provided the line is equipped with a low-pressure safety valve.
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10.4
If pipe sections are to be removed and flanges opened, the lower
bolts should be loosened first and although the lines have been purged,
care should be exercised to avoid contact with any residual material
that drips from the equipment.
10.5
Immediate drying of a chlorine pipe line or container into which
water accidently has been introduced or which has been opened for
repairs or cleaning is essential if corrosion is to be prevented.
10.6
Workers entering tanks should be equipped with suitable personal
protective devices, preferably a self-contained breathing apparatus.
Canister mask should not be used unless the oxygen content is
periodically determined to be suitable for this purpose. At least one
other person should be observing operations from outside the tanks at
all times.
10.7
Under no circumstances should a rescuer enter a tank to remove a
victim of overexposure without proper respiratory protection, a safety
harness and an attached life-line. Another attendant should be available
at all times and the rescuer should be in view of the outside attendant
at all times or in constant communication with him.
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BUREAU OF INDIAN STANDARDS
| Headquarters: |
| Manak Bhavan, 9 Bahadur Shah Zafar Marg, NEW DELHI 110002 |
| Telephones : 323 0131, 323 3375, 323 9402 |
| Fax : 91 11 3234062, 91 11 3239399, 91 11 3239382 |
Telegrams : Manaksanstha
(Common to all Offices) |
| Central Laboratory: |
Telephone |
| Plot No. 20/9, Site IV, Sahibabad Industrial Area, Sahibabad 201010 |
8-77 00 32 |
| Regional Offices: |
| Central : Manak Bhavan, 9 Bahadur Shah Zafar Marg, NEW DELHI 110002 |
323 76 17 |
| *Eastern : 1/14 CIT Scheme VII M, V.I.P. Road, Maniktola, CALCUTTA 700054 |
337 86 62 |
| Northern : SCO 335-336, Sector 34-A, CHANDIGARH 160022 |
60 38 43 |
| Southern : C.I.T. Campus, IV Cross Road, CHENNAI 600113 |
235 23 15 |
| †Western : Manakalaya, E9, Behind Marol Telephone Exchange, Andheri (East), MUMBAI 400093 |
832 92 95 |
| Branch Offices: |
| ‘Pushpak’, Nurmohamed Shaikh Marg, Khanpur, AHMEDABAD 380001 |
550 13 48 |
| ‡Peenya Industrial Area, 1st Stage, Bangalore-Tumkur Road, BANGALORE 560058 |
839 49 55 |
| Gangotri Complex, 5th Floor, Bhadbhada Road, T.T. Nagar, BHOPAL 462003 |
55 40 21 |
| Plot No. 62-63, Unit VI, Ganga Nagar, BHUBANESHWAR 751001 |
40 36 27 |
| Kalaikathir Buildings, 670 Avinashi Road, COIMBATORE 641037 |
21 01 41 |
| Plot No. 43, Sector 16 A, Mathura Road, FARIDABAD 121001 |
8-28 88 01 |
| Savitri Complex, 116 G.T. Road, GHAZIABAD 201001 |
8-71 19 96 |
| 53/5 Ward No. 29, R.G. Barua Road, 5th By-lane, GUWAHATI 781003 |
54 11 37 |
| 5-8-56C, L.N. Gupta Marg, Nampally Station Road, HYDERABAD 500001 |
20 10 83 |
| E-52, Chitaranjan Marg, C-Scheme, JAIPUR 302001 |
37 29 25 |
| 117/418 B, Sarvodaya Nagar, KANPUR 208005 |
21 68 76 |
| Seth Bhawan, 2nd Floor, Behind Leela Cinema, Naval Kishore Road, LUCKNOW 226001 |
23 89 23 |
| NIT BUilding, Second Floor, Gokulpat Market, NAGPUR 440010 |
52 51 71 |
| Patliputra Industrial Estate, PATNA 800013 |
26 23 05 |
| Institution of Engineers (India) Building 1332 Shivaji Nagar, PUNE 411005 |
32 36 35 |
| T.C. No. 14/1421, University P. O. Palayam, THIRUVANANTHAPURAM 695034 |
6 21 17 |
| *Sales Office is at 5 Chowringhee Approach, P.O. Princep Street, CALCUTTA 700072 |
27 10 85 |
| †Sales Office is at Novelty Chambers, Grant Road, MUMBAI 400007 |
309 65 28 |
| ‡Sales Office is at ‘F’ Block, Unity Building, Narashimaraja Square, BANGALORE 560002 |
222 39 71 |
__________________________________
Printed at Pantograph, New Delhi (INDIA).
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