CoP 49.0 - Compressed Gases and Air

Abu Dhabi Occupational Safety and
Health System Framework
(ADOSH-SF)
Code of Practice
CoP 49.0 – Compressed Gases and Air
Version 4.1
February 2026

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Table of Contents
1. Introduction ....................................................................................................................................................... 3
2. Training and Competency ............................................................................................................................. 6
3. Requirements .................................................................................................................................................... 8
3.1 Roles and Responsibilities ................................................................................................................. 8
3.2 Planning and Assessment.................................................................................................................. 9
3.3 Safety Requirements........................................................................................................................... 9
3.4 Compressors and Compression Units .......................................................................................... 11
3.5 Air Receivers (Tanks and Pressure Vessels) ............................................................................. 12
3.6 Pressure Relieving Safety Devices .............................................................................................. 13
3.7 Compressed Gas Cylinders - Portable Cylinders ...................................................................... 15
3.8 Gases with Specific Hazard Classes ............................................................................................. 19
3.9 Gas Cylinder Disposal ........................................................................................................................ 21
3.10 Inspection and Maintenance ........................................................................................................... 21
3.11 Emergency Response ........................................................................................................................ 23
4. References ....................................................................................................................................................... 24
5. Document Amendment Record ................................................................................................................. 25

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1. Introduction
(a) This Code of Practice (CoP) applies to all employers within the Emirate of Abu Dhabi
that uses compressed gasses to include compressed air. This CoP is designed to
incorporate requirements set by UAE and Abu Dhabi Regulatory Authorities. If
requirements of this document conflict with requirements set by another regulatory
authority, employers are required to follow the more stringent requirement.
(b) This CoP sets requirements on how to use, store and transport compressed gases.
(c) Definitions applicable to this CoP:
(i) Absolute Pressure: Based on a zero-pressure reference point, the perfect
vacuum. Measured from this point, standard atmospheric pressure at sea level
is 14.7 pounds per square inch (psi) or 101.325 kilo Pascal’s (kPa). This is usually
expressed as psia where the 'a' indicates an absolute measurement or kPa.
(ii) Air Receiver means an unfired pressure vessel used to store compressed air for
various end uses which are constructed and maintained in accordance with the
applicable local / national regulations, internationally recognized standards and
industrial best practices including ASME Boiler and Pressure Vessel Code Section
VIII.
(iii) Asphyxiant Gas: Any non-toxic gas which displaces atmospheric oxygen below
limits required to support life. These gases are usually colorless, odorless and
tasteless and include nitrogen, argon and helium.
(iv) Compressed Gas: Any gas which when enclosed in a container gives:
1. an absolute pressure reading greater than 276 kPa (40 psi) at 21°C (70°F)
or
2. an absolute pressure greater than 717 kPa (104 psi) at 54°C (129.2°F) or
3. any flammable liquid having a vapor pressure greater than 276 kPa (40
psi) at 38°C (100.4°F).
(v) Compressed Gas Cylinder: A high-pressure vessel designed to transport gas at
pressures above atmospheric, which is made of durable materials meeting
specific requirements and is fitted with a valve to control the release of the gas.
Such cylinders can be of four major types: Type 1 is all-metal, typically steel or
aluminium; Type 2 has a metal liner with a partial composite wrap; Type 3 is fully
composite with a metal liner; and Type 4 is fully composite with a non-metallic
liner. Only cylinders of the types approved by the concerned government
authority shall be used for storage and transportation of gases under pressure,
including liquefied gases.
(vi) Corrosive Gas: A gas that in contact with living tissue causes destruction of the
tissue by chemical action.
(vii) Cryogenic Liquid: A liquid with a normal boiling point below -150°C (-238°F).
(viii) Cryogenic Liquid Cylinder: Pressurized container designed and fabricated to hold
cryogenic fluids. There are three common types of liquid cylinders: gas
dispensing; liquid dispensing; or gas and liquid dispensing.

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(ix) Cylinder Valve: A mechanical device attached to a compressed gas cylinder that
permits flow into or out of the cylinder when the device is in the open position
and prevents flow when in the closed position.
(x) Dewar: Is an open-mouthed, non-pressurized, vacuum-jacketed container used
to hold cryogenic fluids.
(xi) Frangible Disk is a thin piece of metal in a pressure system to relieve excessively
high pressure.
(xii) Fusible Plugs are fittings with an alloy that melts at a predetermined
temperature.
(xiii) Flammable Gas: A substance that meets the definition of a compressed gas
which:
1. is flammable in a mixture of 13% or less (by volume) with air, or
2. has a flammable range with air wider than 12%, at atmospheric
temperature and pressure, regardless of the lower limit.
(xiv) Gauge Pressure: The pressure above or below atmospheric pressure. Therefore,
absolute pressure minus local atmospheric pressure equals gauge pressure and
is usually abbreviated as psig or kPa.
(xv) Handling: Moving, connecting or disconnecting a compressed or liquefied gas
container under normal conditions of use.
(xvi) High-pressure Cylinders, as defined by international standards are those marked
with a service pressure of 900 psi or greater." The term "high pressure" can
therefore be any level prescribed for the equipment or system in use. For
incident prevention purposes, any pressure system shall be regarded as
hazardous.
(xvii) Highly Toxic Gas: A compressed gas that has a median lethal concentration
(LC50) in air of ≤ 200 ppm. A NFPA Health Hazard rating of 4 is given to gases
having an LC50 in air ≤ 1000 ppm. An example of a highly toxic gas is fluorine
with a LC50 of 185 ppm.
(xviii) High Pressure Gas: A gas in a container that has a pressure of 3448 kPa (500
psig) or higher at 21.1°C (70°F).
(xix) Inert Gas: A gas which is chemically inactive.
(xx) Liquefied Gas: A fluid within a pressurized container, other than in solution,
which exists both as a liquid and gas at 20°C (68°F). Examples include propane,
butane, ammonia, carbon dioxide, and sulfur dioxide.
(xxi) Low Pressure Tank: A tank designed to operate at pressure above 0.35 kg/cm2
but not to exceed 1.055 kg/cm2.
(xxii) Manifold: A gas distribution system which transfers product through multiple
outlets/inlets to or from compressed gas containers.
(xxiii) Non-flammable Gas: A gas which, within the packaging, exerts an absolute
pressure of 280 kPa (40 psi) or greater at 20°C (68°F) but is not a flammable gas
as defined previously.
(xxiv) Oxidizing Gas: A gas that can support and accelerate combustion of other
materials.
(xxv) Pressure Vessel: A tank designed to operate at pressure above 1.055 kg/sq cm.

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(xxvi) Pressure Regulator: A mechanical device used to safely control the discharge
pressure of a compressed gas from a container.
(xxvii) Pressure Relief Device: A pressure and/or temperature activated device used to
prevent the pressure from rising above a predetermined maximum and thereby
prevent rupture of a pressurized container.
(xxviii) Pyrophoric Gas: A gas that will spontaneously ignite in air at or below 54.4°C
(130°F). Examples include silane and phosphine.
(xxix) SCF (Standard Cubic Foot): One cubic foot of gas at 21°C (70°F) and 101.325 kPa
(14.696 psia).
(xxx) Safety Valves: frequently called "pop" valves because they pop full open when
a preset pressure is exceeded.
(xxxi) Relief Valves: Do not "pop" but open slightly and then open further as pressure
increases.
(xxxii) Storage: Holding of gas, in its packaging, either on a temporary basis or for an
extended period in such a manner as to not constitute usage of the gas.
(xxxiii) Toxic Gas: A gas having a Health Hazard of 3 or 4 as defined in
NFPA 704,
Standard System for the Identification of the Fire Hazards of Materials.

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2. Training and Competency
(a) Employers shall ensure that OSH training complies with the requirements of:
(i)
ADOSH-SF – Element 5 – Training, Awareness and Competency.
(ii)
ADOSH-SF – Mechanism 7.0 – Occupational Safety and Health Practitioner and
Service Provider Registration.
(b) Employers shall ensure all relevant employees and contractors that perform tasks
that work with or near compressed gasses receive training that includes at a
minimum:
(i) physical hazards associated with compressed gases;
(ii) design specification, capabilities and limitations of compressed gas storage
systems and their uses at the work site;
(iii) methods and procedures that will prevent exposure to compressed gases or
hazards associated with compressed gases;
(iv) the importance of control measures;
(v) safe work practices;
(vi) required use, maintenance and storage of PPE;
(vii) emergency response procedures;
(viii) safe handling and storage;
(ix) health hazards associated with compressed gases used at the work site;
(x) signs and symptoms of exposure to compressed gases used at the work site; and
(xi) operator maintenance requirements for compressed gas systems.
(c) Employers shall ensure managers and supervisors of operators of compressed gas
systems shall be trained on:
(i) requirements listed in Section 2(b);
(ii) maintenance requirements of compressed gas system to ensure they are working
appropriately and within specifications;
(iii) how to recognize unsafe work practices when working with compressed gas; and
(iv) how to identify when the compressed gas systems are not working appropriately.
(d) Refresher training shall be provided at appropriate intervals and include the criteria
listed in Section 2(b) of this CoP.
(e) Employers shall maintain a record of the required training that contains the
following:
(i) name and ID number;
(ii) Emirates ID number of the employee;
(iii) subject(s) of training;

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(iv) date(s) of training; and
(v) person providing the training.

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3. Requirements
3.1 Roles and Responsibilities
3.1.1 Employers
(a) Employers shall undertake their roles and responsibilities in accordance with the
general requirements of
ADOSH-SF – Element 1 – Roles, Responsibilities and Self-
Regulation Section 3.2.5.
(b) Employers shall be responsible for performing a risk assessment in accordance with
ADOSH-SF – Element 2 – Risk Management to determine the risks associated with
compressed gases and to identify control measures and safe work practices required
to reduce employee’s exposures to compressed gases.
(c) Employers shall implement the Occupational Health and Safety hierarchy of controls,
ADOSH-SF – Element 2 – Risk Management, when developing control measures to
remove or reduce employee exposure to hazards associated with exposure to
compressed gases.
(d) Employers shall ensure that protective equipment or other control measures shall be
used to keep the exposure of employees to compressed gases and hazardous
materials/chemicals within limits prescribed by applicable federal and local exposure
standards.
(e) Employers shall develop and implement an inspection, testing and preventative
maintenance plan to ensure compressed gas systems are safe and working efficiently
and according to manufacture specifications and applicable legal requirements.
(f) Employers shall ensure compressed gases systems are tested and inspected regularly
(at a minimum annually) to ensure the system work in accordance with manufactures
specifications.
(g) Employers shall monitor the use of compressed gases systems to ensure employees
are using compressed gases appropriately.
3.1.2 Employees
(a) Employees shall undertake their roles and responsibilities in accordance with the
general requirements of
ADOSH-SF – Element 1 – Roles, Responsibilities and Self-
Regulation Section 3.2.7.
(b) Employees shall report any activity or defect relating to compressed gases which they
believe is reasonably foreseeable to endanger their safety or that of another person.
(c) Employees shall comply with safe work practices and standard operating procedures.
(d) Employees shall use appropriate equipment or safety devices provided by the
employer in accordance with any training or instruction received in the use of the work
equipment or device concerned.

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(e) Employees shall not perform any task requiring training until they have received the
required training and it is documented.
(f) Employees shall not operate any piece of equipment that they are not familiar with,
competent to operate and/or appropriately trained on its use.
3.2 Planning and Assessment
(a) Employers shall ensure the following:
(i) an assessment of the various risks is undertaken and systems of work are
established which are safe to all parties involved or affected including the public;
(ii) that appropriate control measures are implemented in order to manage activities
safely and without risk to health;
(iii) that for the Building and Construction Sector the management of compressed
gases requirements are included in the Pre-Tender Safety and Health Plan in
accordance with
ADOSH-SF – CoP 53.0 – OSH Management During “Construction
Work”; and
(iv) that associated safe systems of work, and site rules are included in Safety and
Health Construction Management Plan (OSH-CMP) in the case of the Building and
Construction Sector in accordance with
ADOSH-SF – CoP 53.0 – OSH Management
During “Construction Work”.
3.3 Safety Requirements
(a) When performing risk assessments in accordance with
ADOSH-SF – Element 2 – Risk
Management, the following shall be considered:
(i) the condition of the equipment being used (compressors, hoses, couplings etc.)
and if they are rated by an appropriate International Standard for their intended
use;
(ii) the type, frequency and duration of the compressed gas work;
(iii) the environment in which the compressed gas work is to be undertaken (e.g.
dirty/dusty conditions, uneven work surfaces, cramped conditions);
(iv) the pressure at which the compressor is operating at;
(v) the level of experience of the personnel involved in the work; and
(vi) other identified hazards associated with the work.
(b) When using compressed gas systems (to include pneumatic tools), the following
requirements shall be met:
(i) pipes, hoses, and fittings shall display the rating of the maximum pressure of the
compressor. Compressed air pipelines shall be identified and tested to maximum
working pressure;
(ii) under no circumstances shall the pressure of the compressed air exceed the
maximum working pressure of any of the components in use;
(iii) couplings shall have safety clips fitted to them to prevent inadvertent
uncoupling when under pressure – makeshift tie-wire shall not be used;

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(iv) ensure all components comply with the appropriate International Standard for
their intended use and are regularly maintained in a fit for purpose condition;
(v) the setting of safety valves or reducing valves shall only be adjusted by a
competent person;
(vi) air supply shutoff valves shall be located, as near as reasonably practicable, at
the point-of-operation;
(vii) air hoses shall be kept free of grease and oil to reduce the possibility of
deterioration;
(viii) hoses shall not be located across floors or aisles where they are liable to cause
personnel to trip and fall. When reasonably practicable, air supply hoses shall be
suspended overhead, or otherwise located to afford efficient access and
protection against damage;
(ix) hose ends shall be secured to prevent whipping if an accidental cut or break
occurs;
(x) pneumatic impact tools, such as riveting guns, shall never be pointed at a person;
(xi) before pneumatic tools are disconnected (unless it has quick disconnect plugs),
the air supply shall be turned off at the control valve and the tool bled;
(xii) compressed air shall not be used under any circumstances to clean dirt and dust
from clothing or off a person’ s skin;
(xiii) air used for cleaning shall be regulated to 15 psi unless equipped with diffuser
nozzles to provide lesser pressure;
(xiv) static electricity may be generated through the use of pneumatic tools. This type
of equipment shall be grounded or bonded if it is used where fuel, flammable
vapours or explosive atmospheres are present;
(xv) when used for cleaning, the compressed air equipment (air nozzle) shall reduce
the outlet (working) air pressure to less than 30 pounds square inch (psi) at the
discharge tip. In-line chip protection shall be used when airlines are connected
directly to a compressed air system. This does not mean that the supply air or
line pressure be reduced to 30 psi as long as the static (dead head) pressure
exiting the nozzle when restricted does not exceed the mandatory maximum
30psi;
(xvi) reduction of air pressure for cleaning can be done with nozzles and tips designed
for this purpose. Employees shall not remove, damage, cover (e.g. tape), replace
or in any way alter the equipment provided for this purpose. Nozzles that have
been altered or "home-made" and shall not be used;
(xvii) goggles, face shields or other eye and hearing protection shall be worn by
personnel using compressed air for cleaning equipment, in compliance with
ADOSH-SF – CoP 2.0 – Personal Protective Equipment; and
(xviii) all defects shall be immediately reported to the employer and the use of the
defective equipment shall be ceased.
(c) The handling, storage, utilization, and inspection of all compressed gases in cylinders,
portable tanks, rail tank-cars, or motor vehicle cargo tanks shall be in accordance with
current requirements of the Emirates Authority for Standardization and Metrology
(ESMA) while recognizing Section 3.10 requirements regarding inspection.

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3.4 Compressors and Compression Units
(a) When a gas compressor plant or a gas processing plant discharges gas into a line to
which other sources of gas supply are connected there shall be a valve installed in the
plant's discharge line, or lines, for the purpose of automatically preventing the return
flow of gas. The valve shall, where reasonably practicable, be located outside of the
plant but within a reasonable distance of the plant.
(b) Gas compressor discharge lines shall have a pressure-relieving safety device. There
shall be no valve located between the pressure relieving safety device and the
cylinder or cylinders it is to protect. The pressure-relieving safety device shall be set
to open at a pressure not to exceed the maximum allowable working pressure of the
cylinder. The relieving capacity of the pressure relieving safety device shall be such
as to prevent a rise of pressure in the cylinders of more than 10 percent above their
maximum allowable working pressure. The pressure-relieving valve shall be bench
tested, calibrated and certified.
(c) Where a gas compressor pressure-relieving safety device discharges into the
atmosphere, the discharge outlet shall be located outside of the compressor building
and if it discharges adjacent to the building, it shall have the discharge outlet located
above the compressor building eaves.
(d) Where hazardous quantities of liquid may be present in the incoming gas to
compressors, an inlet scrubber shall be provided and a device installed thereon to give
either audible warning or shut down the compressors in case the liquid in the scrubber
exceeds a predetermined level.
(e) Gas lines which enter plants, and which are connected to compressor intakes, shall be
provided with shut-off valves in a safe location.
(f) While maintenance work of a nature requiring the opening of lines or equipment
containing gas is being performed on a compressor or its suction or discharge piping,
employees shall be protected from being endangered by escaping gas by closing and
locking of the valves in the intake and discharge lines. If the closing and locking of the
lines is inappropriate, the lines shall be blinded or other equally effective means taken
to prevent the escape of gas. Lock out/Tag out shall be done in accordance with
ADOSH-SF – CoP 24.0 – Lock Out/Tag Out.
(g) Air and gas compressor engines of over 30 horsepower shall be provided with means
other than manual for starting, providing that manual starting may be used in
emergencies.

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3.5 Air Receivers (Tanks and Pressure Vessels)
(a) The normal operating conditions of the tank or vessel shall not exceed the design
pressure or temperature.
(b) Internal bracing will include vent holes to prevent the forming of gas pockets or liquid
pools when liquid level rises or falls.
(c) The smallest diameter dimension on any manhole will not be less than 400 mm circular
or 280 x 400 mm oval or 255 x 410 mm oval.
(d) Air receivers shall be designed, fabricated, tested stamped and installed in accordance
with the applicable local / national regulations, internationally recognized standards
and industrial best practices including the
ASME Boiler and Pressure Vessel Code,
Section VII.
(e) Air receivers shall be installed to ensure accessibility for maintenance and draining.
(f) To provide for removal of accumulated water and oil, a drain pipe and valve shall be
installed at the lowest point of every air receiver. The drain valve shall be opened at
a minimum daily in order to drain the air receiver of accumulated water and oil.
(g) Drain valve, safety valve, examination holes and manholes shall be accessible.
(h) Every air receiver shall be equipped with a pressure gauge which is readily visible and
with spring loaded safety valves which prevents the receiver from exceeding the
maximum allowable working pressure by more than 10 percent.
(i) Valves, indicator devices, and controlling devices shall be constructed, located, and
installed so that they cannot be readily rendered inoperable.
(j) Tank and vessel supports shall be installed on firm foundations. Tank supports shall
be of concrete, masonry, or steel.
(k) Tanks without supports shall rest on the ground or on foundations made of concrete,
masonry, piling or steel.
(l) Atmospheric tanks shall be vented to prevent the development of vacuum pressure
appropriate to distort the tank or exceed the design pressure as a result of filling or
emptying, and atmospheric temperature changes.
(m) Normal vents shall be sized in accordance with good engineering practice or shall be
at least as large as the filling or withdrawal connection, whichever is larger but in no
case less than 30 mm inside diameter.
(n) Any physical work other than that permitted (e.g. drilling, welding, etc.) to tank or
vessel after stamping shall be performed by a manufacturer-approved qualified
engineer or third-party inspection agency to maintain the integrity of the stamp on
the tank. Tanks shall be periodically re-inspected at a frequency determined by the
risk assessment and applicable legal and international standards.

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(o) Tank/Vessel Record - A permanent and progressive record for each tank and vessel
shall be maintained at the plant where the tank and vessel is located. The record shall
be available for inspection by concerned authorities and shall include the following:
(i) serial or identification number of the tank or vessel;
(ii) established safe working pressure of the tank or vessel for the working
temperature;
(iii) relief valve setting;
(iv) maximum working temperature;
(v) manufacturer's data reports, when obtainable, and all data pertaining to tests,
inspections and calculations used in establishing the safe working pressure; and
(vi) air Receiver drawing with all the components attached to the vessel, such as
valves, relief valves, pressure gauges etc.
3.6 Pressure Relieving Safety Devices
(a) Only qualified personnel shall be allowed to repair or adjust pressure regulating
equipment.
(b) Valves, gauges and other regulating devices shall be installed on compressor
equipment in such a way that cannot be made inoperative, normally locked open.
(c) Air tank safety valves shall be set no less than 15 psi or 10 percent (whichever is
greater) above the operating pressure of the compressor but never higher than the
maximum allowable working pressure of the air receiver.
(d) Air lines between the compressor and receiver shall not be equipped with stop valves.
Where stop valves are necessary and authorized, standard safety valves shall be
installed between the stop valves and the compressor.
(e) The Safety valves shall be set to blow at pressures slightly above those necessary to
pop the receiver safety valves.
(f) Blow-off valves shall be located on the equipment and shielded so sudden blow-offs
will not cause personnel injuries or equipment damage.
(g) Case iron seat or disk safety valves shall be approved in compliance to applicable
standards and stamped for intended service application.
(h) If the design of a safety or a relief valve is such that liquid can collect on the discharge
side of the disk, the valve shall be equipped with a drain at the lowest point where
liquid can collect.
(i) Safety valves exposed to freezing temperatures shall be located so water cannot
collect in the valves. Frozen valves shall be thawed and drained before operating the
compressor.
(j) Safety relief valves installed on pressure vessels shall be constructed, installed, and
maintained in accordance with relevant international standards.

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(k) No pressure vessel shall be operated in excess of the allowable working pressure of
the vessel as established by codes or the maximum allowable working pressure as
established for the vessel at its last inspection, whichever is the least. Pressure-
relieving devices shall be set to prevent the pressure from rising more than 10% above
the maximum allowable working pressure.
(l) A permanent and progressive record of pressure-relieving safety devices in service,
showing the serial or identification number, the location, the pressure setting, the
free orifices area in sq cm, the date of installation in service, and the date of testing
shall be maintained at the location where the pressure relieving safety device is
located or at the supervising office.
(m) A vessel having a stop valve that shuts off the vessel from its pressure relieving
device, shall be protected by an additional safety device, if the vessel may become
entirely filled with liquid and if it is reasonably practicable that pressure may be
generated by continued input of heat through exchanger tubes or similar devices, or
by exposure to sun or adjacent hot equipment. This additional safety device shall be
connected to the vessel at all times. The additional safety device may be set higher
so that the pressure cannot rise higher than 20% above the safe working pressure.
(n) The aggregate capacity of the pressure-relieving safety devices applied to any
vessel or system of vessels for the release of vapor shall be appropriate to carry off
the maximum quantity of vapor that can be generated in, or supplied to, the attached
equipment within the variations of normal operation, without permitting a rise in
pressure within the vessel of more than 16 percent above the safe working pressure.
(o) Outlets from pressure-relieving safety devices shall be appropriately secured and
shall lead to a safe place of discharge. Pressure-relieving safety device stacks which
are open to the atmosphere shall be provided with a drain. The size of outlets or
stacks shall be such that any pressure drop shall not reduce the relieving capacity of
the relieving devices below that required to protect the vessel. No stop valve shall
be placed on a discharge line from a pressure relieving safety device except when
such discharge line discharges to a common header, in which case such stop valve
shall be locked or sealed open and shall be closed, while the vessel is in operation,
only by a person definitely assigned to such duties by the employer, and such person
shall not leave the location until the stop valve is opened and relocked or resealed.
(p) Each pressure-relieving safety device installed on operating equipment shall be
maintained so as to ensure the appropriate functioning of the device at the intended
pressure. Such maintenance shall include inspection, testing, and the repair of the
pressure-relieving safety devices at frequencies as required by the service
conditions.
(q) Each pressure-relieving safety device in service shall have serial or identification
number stamped upon it and in addition a metal plate or metal tag shall be attached
to each such device and shall show the pressure setting and the date the device was
installed in service.
(r) All safety valves shall be tested on a regular basis to ensure they are in good
operating condition. This can be performed by a competent external entity and
records shall be maintained at the facility and accessible to inspectors and
maintenance staff.

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3.7 Compressed Gas Cylinders - Portable Cylinders
(a) The handling, storage, utilization, and inspection of all compressed cylinders shall be
in accordance with current requirements of the ESMA while recognizing Section 3.10
requirements regarding inspection.
(b) Compressed gas cylinders require special construction, handling, storage,
transportation and disposal techniques. This Section describes requirements for safe
handling of Compressed Gas Cylinders within the workplace.
(c) Gases drawn from cylinders are usually characterized as:
(i) permanent gases having boiling points of -150oF or lower and cannot be liquefied
at room temperature no matter how high the pressure. Such gases include oxygen,
nitrogen, and helium;
(ii) liquid gas which liquefy at temperatures of -130oF or higher at one atmosphere,
but can be liquefied and maintained as liquids at higher pressures. Such gases
include propane, chlorine, and butane. Carbon dioxide is in this category, but
becomes a solid rather than a liquid; and
(iii) dissolved gases in common use such as acetylene dissolved in acetone which holds
35 times its own volume of acetylene.
(d) Compressed gas cylinder users shall maintain and refer to the specific Safety Data
Sheets (SDS) for the substances contained in the cylinder for more details. Specific
standards for some compressed gases such as acetylene, hydrogen, oxygen, etc.
shall be considered.
3.7.1 Construction and Marking of Cylinders
(a) All portable cylinders used for the storage and shipment of compressed gases shall be
constructed and maintained in accordance with the requirements of the Compressed
Gas Association (CGA) and applicable local / national regulations and internationally
recognized standards appropriate to the use or intended use of the cylinder.
(b) Compressed gas cylinders shall be legibly marked, for the purpose of identifying the
gas content, with either the chemical or the trade name of the gas. Such marking shall
be by means of stencilling, stamping or labelling, and shall not be readily removable.
Whenever reasonably practicable, the marking shall be located on the shoulder of the
cylinder. Shoulder label should contain Hazchem symbol, UN number and basic safety
precautions for the gas.
(c) Labels shall be securely attached to cylinders so that they cannot be inadvertently or
accidentally detached during use, transport and storage.
(d) Numbers and markings stamped into cylinders shall not be tampered with.
(e) Compressed gas cylinders shall be equipped with connections complying with the
applicable local / national regulations, internationally recognized standards such as
BS
341 Outlet connections, CGA V-1, DIN, and
American National Standard Compressed
Gas Cylinder Valve Outlet and Inlet Connections, ANSI B57.1-1965.

ADOSH-SF – Codes of Practice
CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 16 of 26
(f) Cylinders with a water weight capacity of over 30 pounds (13.6 kg) shall be equipped
with a means of connecting a valve protection cap or with a collar or recess to protect
valve.
3.7.2 Compressed Gas Cylinder Handling
(a) Cylinders shall always be considered full and shall be handled carefully.
(b) Cylinders which are designed to accept valve protection devices shall be equipped
with such devices when the cylinders are in transport, storage, not in use between
shifts, or otherwise not connected for use.
(c) Unless cylinder valve is protected by a recess in the head, the metal cap shall be kept
in place to protect the valve when the cylinder is not connected for use.
(d) Threads on a regulator shall be identical to those on the cylinder valve outlet.
Connections that do not fit shall not be forced on.
(e) All parts of a compressed gas cylinder shall be checked before use. All cylinders shall
be in good condition with an operable valve or regulator. Cylinders without valves and
regulators shall be capped.
(f) Flashback devices shall be fitted at both the regulator and torch end of oxygen/fuel
gas systems. Safety devices in valves or on cylinders shall not be tampered with.
(g) Cylinder valves shall be opened slowly. Cylinders without hand wheel valves shall be
opened with a spindle key, special wrench, or other tool provided or approved by the
gas supplier.
(h) Valves of empty cylinders shall be closed.
(i) Cylinders shall not be dropped or struck or permitted to strike each other violently.
(j) Cylinder valves not provided with fixed hand wheels shall have keys or handles on
valve spindles or stems while cylinders are in service. In multiple cylinder installations
only one key or handle is required for each manifold.
(k) Cylinder valves shall not be tampered with nor shall any attempt be made to repair
them. The supplier shall be contacted immediately if damage occurs.
(l) Complete removal of the stem from a diaphragm-type cylinder valve shall be avoided.
(m) Cylinders shall never be used as rollers or supports.
(n) Cylinders shall never be used without a pressure-reducing regulator attached to the
cylinder valve except where cylinders are attached to a manifold – in which case the
regulator shall be attached to the manifold header.
(o) Before making connection to a cylinder valve outlet, ensure that the valve outlet is
fitted with a dust cap and is free from any dust or dirt. After fixing the regulator or a
hose/pigtail, ensure that the valve opening shall always be pointed away from the
body and not toward anyone else.

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 17 of 26
(p) Regulators and pressure gauges shall be used only with gases for which they are
designed and intended.
(q) Employers shall not attempt to repair or alter cylinders, valves, or attachments. This
shall be done only by the manufacturer / approved service agent.
(r) Oil or grease shall never be used as a lubricant on valves or attachments of oxygen
cylinders. Oxygen cylinders and fittings shall be kept away from oil and grease; such
cylinders or apparatus shall not be handled with oily hands, gloves, or clothing.
(s) Oxygen shall not substitute for compressed air in pneumatic tools, in oil pre-heating
burners, to start internal combustion engines, or to remove dust from clothing. It shall
be used only for the purpose for which it is intended.
(t) Cylinders shall never be brought into confined spaces or unventilated rooms.
(u) DO NOT use or compress Acetylene in a free state at pressure higher than 15 pounds
per square inch.
(v) Never completely empty a cylinder; there shall always be a minimum residual gas
pressure of 30psi.
(w) Before a regulator is removed, the cylinder valve shall be closed and the gas released
from the regulator.
(x) Unless the cylinder valve has first been closed tightly, no attempt shall be made to
stop a leak between the cylinder and the regulator.
(y) If a leak occurs in a fuel gas cylinder it shall be taken out of use immediately and
handled as follows:
(i) the valve shall be closed and the cylinder taken outdoors well away from any
ignition source. The cylinder shall be tagged (Do Not Use, No Smoking, No Ignition
Source) and the supplier notified; and
(ii) a regulator attached to the valve may be used temporarily to stop a leak through
the valve seat.
(z) When flammable gas lines or other parts of equipment are being purged of air or gas,
open lights or other sources of ignition shall not be permitted near uncapped
openings.
3.7.3 Transportation of Compressed Gas Cylinders
(a) Unless cylinders are secured on a specifically designed rack / equipment, regulators
shall be removed and valve-protection devices put in place prior to movement.
(b) Compressed gas cylinders in portable service shall be conveyed by appropriate trucks
to which they are securely fastened; and all gas cylinders in service shall be securely
held in substantial racks or secured to other rigid structures so that they will not fall
or be knocked over.
Note: Exception: When it is not reasonably practicable to transport cylinders neither by truck, nor to
bring in racks to point of operation, as in some construction work, cylinders may be carried in, and

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 18 of 26
appropriately secured in an appropriate manner. For short distances, cylinders may be moved by tilting
and rolling them on their bottom edges.
(c) Gas cylinders transported by crane, hoist, forklift, or derrick shall be handled in
appropriate cradles, nets or skip boxes, and shall never be lifted by magnet or by
slings, unless the slings are designed and constructed to prevent accidental release
of the cylinders.
(d) Valve protection devices shall not be used for lifting cylinders. Exception: Valve
protection devices may be used for manual lifting if they were designed for that
purpose.
(e) Bars shall not be used under valves or valve protection caps to pry cylinders loose
when frozen to the ground or otherwise fixed; the use of warm (not boiling) water is
recommended.
(f) Ensure cylinder valves shall be closed before moving cylinders.
3.7.4 Storage of Compressed Gas Cylinders
(a) Cylinders shall always be secured to prevent them falling over. Chains or a clamp-plus-
strap is an acceptable method of keeping cylinders upright. The chain or strap shall be
placed above the midpoint of the cylinder to keep it from falling over.
(b) Cylinders of compressed gas shall be stored in areas where they are protected from
external heat sources such as flame impingement, intense radiant heat, electric arc, or
high temperature steam lines.
(c) Inside of buildings, cylinders shall be stored in a well-protected, well-ventilated, dry
location, at least six meters from highly combustible materials such as oil or excelsior.
Assigned storage spaces shall be located where cylinders will not be damaged by
passing or falling objects, or subject to tampering by unauthorized persons.
(d) Storage rooms for cylinders containing flammable gases shall be well ventilated to
prevent the accumulation of explosive concentrations of gas; no source of ignition
shall be permitted; smoking shall be prohibited.
(e) Storage areas shall contain the appropriate safety signage, in accordance with
ADOSH-SF – CoP 17.0 – Safety Signs and Signals.
(f) Employers shall ensure that only authorized persons have access to compressed gases
storage areas.
(g) Cylinders shall not be stored in temperatures above 51 degrees Celsius or near sources
of heat such as radiators/furnaces, or near highly flammable substance like gasoline,
oil, or volatile liquids.
(h) Do not store incompatible gases together. Oxygen cylinders in storage shall be
separated from fuel gas cylinders or combustible materials (especially oil or grease) a
minimum distance of 6 meters or by a non-combustible barrier at least 2 meters high,
or a minimum of 46 centimeters above the tallest cylinder and having a fire-resistance
rating of at least one hour.

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(i) Compressed gas cylinders shall be stored or transported in a manner to prevent them
from creating a hazard by tipping, falling or rolling.
(j) Liquefied fuel-gas cylinders shall be stored or transported in a position so that the
safety relief device is in direct contact with the vapor space in the cylinder at all times.
(k) Acetylene and liquefied fuel gas cylinders shall be stored with the valve end up.
(l) Cylinders stored in the open shall be protected from contact with the ground and
against weather affects.
(m) Cylinders shall not be placed where they might form part of an electric circuit.
3.8 Gases with Specific Hazard Classes
(a) The following information regarding specific classes of gases are additional
requirements to be used in conjunction with the general usage requirements listed in
preceding sections.
3.8.1 Corrosive Gases:
(a) Corrosive gases, examples include chlorine, hydrogen chloride, fluorine, hydrogen
fluoride, hydrogen sulfide, carbon monoxide and carbon dioxide:
(i) when using corrosive gases, equipment and lines shall be checked daily for damage
and leaks;
(ii) a diaphragm gauge shall be used with corrosive gases that would destroy a steel
or bronze gauge. Check with gas supplier for recommended equipment; and
(iii) after removing regulators, employers shall inspect them for damage and flush them
with dry air or nitrogen.
3.8.2 Cryogenic Liquids and Gases:
(a) Cryogenic liquids and their boil-off vapors rapidly freeze human tissue and cause
embrittlement of many common materials which may crack or fracture under stress.
All cryogenic liquids produce large volumes of gas when they vaporize (at ratios of
600:1 to 1440:1, gas: liquid) and may create oxygen-deficient conditions. Examples
of common cryogenic liquids include liquid oxygen, hydrogen, helium, and liquid neon.
The following information applies to the use and handling of cryogenics:
(i) employees shall use appropriate personal protective equipment (PPE) including
insulated gloves and eye protection (goggles and a face shield) during any
transfer of cryogenic liquid;
(ii) emergency procedures shall be developed for accidental exposures to include skin
contact with a cryogenic liquid;
(iii) only equipment, valves and containers designed for the intended product and
service pressure and temperature shall be used;
(iv) employers shall inspect containers for loss of insulating vacuum. Repairs shall be
made by the manufacturer or a manufacturer approved entity;

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 20 of 26
(v) transfer operations involving open cryogenic containers such as dewars shall be
conducted slowly to minimize boiling and splashing of the cryogenic fluid;
(vi) ice or other foreign matter shall not be allowed to accumulate beneath the
vaporizer or the tank;
(vii) all cryogenic systems including piping shall be equipped with pressure relief
devices to prevent excessive pressure build-up;
(viii) pressure reliefs shall be directed to a safe location;
(ix) employees shall not tamper with pressure relief valves or the settings for the
valves; and
(x) hot air, steam or hot water shall be used to thaw frozen equipment. Do not use
water to thaw liquid helium equipment.
3.8.3 Flammable Gases:
(a) The following information applies to the use and handling of flammable gases. Some
common examples of flammable gases include acetylene, hydrogen, methane,
propane and iso-butane:
(i) flammable gases, except for protected fuel gases, shall not be used near ignition
sources. Ignition sources include open flames and sparks, sources of heat,
oxidizing agents and ungrounded or non-intrinsically safe electrical or electronic
equipment;
(ii) portable fire extinguishers shall be available for fire emergencies. The fire
extinguisher shall be compatible with the apparatus and the materials in use;
(iii) flames shall not be used for detecting leaks. A compatible leak detection solution
shall be used for leak detection;
(iv) spark proof tools shall be used when working with or on a flammable compressed
gas cylinder or system;
(v) access doors to areas which use or store flammable gases shall be posted “No
Smoking” and "No Open Flames";
(vi) manifold systems shall be designed and constructed by competent personnel
who are thoroughly familiar with the requirements for piping of flammable gases.
Manifolds shall comply with the applicable standards;
(vii) standard specifications shall be identified before starting design and
construction; and
(viii) consultation with the gas supplier shall be completed before installation of
manifolds.
3.8.4 Fuel, High Pressure and Oxidizing Gases:
(a) The following information applies to the use and handling of fuel, high pressure and
oxidizing gases:
(i) use of fuel gases shall comply with applicable national & international standards
including NFPA and industrial best practices;

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 21 of 26
(ii) employers shall have a qualified engineer or other competent person design and
oversee the installation of Oxygen-Fuel Gas Systems for Welding, Cutting and
Allied Processes;
(iii) high pressure gases can be rated up to 3000 pounds per square inch (psi). Typical
uses include MIG (Metal Inert Gas) welding gas mixtures, cryogenics, non-toxic gas
distribution, medical gas distribution, and emergency oxygen services;
(iv) in addition to any gas specific hazards, high pressure gases shall carry the following
hazard label : “CAUTION: HIGH PRESSURE GAS”; and
(v) do not use oil in any apparatus where oxygen will be used. Gauges and regulators
for oxygen shall bear the warning “OXYGEN - USE NO OIL”.
3.8.5 Toxic and Highly Toxic Gases:
(a) The following information applies to the use of toxic and highly toxic gases;
(i) unless otherwise indicated, all gases shall be stored in a continuously mechanically
ventilated gas cabinet, fume hood or other enclosure;
(ii) small quantities (e.g. lecture cylinders) or dilute concentrations of these gases may
be stored outside of a ventilated enclosure;
(iii) audible alarms shall be utilized in ventilated hoods that are dedicated to toxic gas
usage or storage; and
(iv) Standard Operating Procedures (SOP’s) for processes or procedures which use toxic
or highly toxic gases shall be developed that include emergency response actions.
3.9 Gas Cylinder Disposal
(a) When feasible, employers shall purchase compressed gas only from manufacturers
that will agree to take back the empty cylinder.
(b) A cylinder is considered empty when the container pressure is 35psi or less.
(c) Refillable cylinders shall be returned to the authorized supplier or directly to the
vendor.
(d) If a refillable cylinder is encountered that does not have a manufacturer label, contact
approved Registered Service Providers, as per
ADOSH-SF – CoP 54.0 – Waste
Management, for advice on disposal and / or identifying the manufacturer through
stamp marks on the cylinder.
(e) Maintain manufacturer labels and label the cylinder as “Empty”.
(f) Appropriate identification of the contents of all cylinders is required and is the
responsibility of the employer and/or cylinder owner.
3.10 Inspection and Maintenance
(a) Compression Units shall be inspected at a minimum annually by a competent person
licensed by the competent authority.

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 22 of 26
(b) Gas Cylinders:
(i) Gas cylinders shall be hydrostatically tested as per the standard to which the
cylinders are manufactured, the test date shall be stamped onto the shoulder of
the cylinder each time the cylinder is tested, and testing intervals shall be as below:
1. Cylinders made to EU/International standards should be tested in accordance
with
BS EN ISO18119:2018;
2. Cylinders made to DOT (Department of Transportation-USA) standards should
be tested in accordance with DOT Regulations;
3. For any other cylinders if there is no clear correlation with one of the above-
mentioned standards (EU/ISO/DOT), it is recommended to use DOT standard
and the testing interval shall be 5 years;
Note: The interval between periodic inspections and tests may be extended under specific
conditions more than stipulated above provided this practice is approved by a UAE Competent
Authority.
(ii) cylinders in use are allowed to exceed the above test interval by one year, but shall
be tested prior to refilling if sooner; and
(iii) Low-Pressure Cylinders (0.35 kg/cm2 to 1.055 kg/cm2) are exempted from the
Hydrostatic Test.
(c) Air Receiver shall be tested by a competent person or a skilled third party agency at a
frequency defined by the applicable legal requirements, manufacturer
recommendations and/or employer’s inspection & maintenance scheme. Inspection
shall include, but not be limited to:
(i) visual Examination each six month by Employer’s competent person;
(ii) thorough Internal and External Visual Inspection plus a Gas Leak test at full
working pressure OR Internal overpressure test plus a Gas Leak Test at full working
pressure; and
(iii) thorough internal and external visual examination and gas leak test to maximum
working pressure. If the competent person deems it necessary, an overpressure
test to 1.1 times the maximum working pressure shall be conducted.
(d) Pipework shall be tested by a competent person or a skilled third-party agency at a
frequency defined by the applicable legal requirements, manufacturer
recommendations and/or employer’s inspection & maintenance scheme. Inspection
shall include, but not limited to:
(i) visual examination;
(ii) gas leak test at maximum working pressure of the system; and
(iii) internal pressure test to 1.5 times maximum working pressure of the system plus
gas leak test at maximum working pressure of the system.
(e) Electronics shall be visually examined, function tested (to include protective devices),
and continuity and resistance testing of any cables by the employer competent person
or a skilled third-party agency.

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3.11 Emergency Response
(a) Emergency Response procedures compliant to
ADOSH-SF – Element 6 – Emergency
Management shall be developed for all compressed gas systems. Requirements for
emergencies involving compressed gas cylinders include leaks, fire, explosions etc. as
identified through the Risk Assessment as required by Section 3.1(b) of this CoP.
(b) First aid procedures in accordance with
ADOSH-SF – CoP 4.0 – First Aid and Medical
Treatment shall be developed.
(c) Emergency and first aid procedures shall include:
(i) the provision of first aid facilities, kits and officers to appropriately deal with
compressed air injuries, such as air and foreign particle injection;
(ii) provisions to immediately shut down air compressors isolate gas cylinders etc. in
the event of an emergency;
(iii) contact details for external emergency services and the relevant on site personnel;
(iv) evacuation routes and emergency assembly points; and
(v) for toxic gases leaks, the cylinder shall be removed to an isolated, well-ventilated
area, but only if this is reasonably practicable while maintaining personal safety. A
general evacuation of the building may be necessary and have the cylinder
approached only by trained emergency response personnel wearing protective
apparel and self-contained breathing apparatus (SCBA).

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 24 of 26
4. References
•
U.A.E Standard 215 E / 1995 (Industrial Safety and Health Regulations -
Equipment- Tanks, Pressure Vessels, Boilers and Compressed Gas
Equipment)
•
UK HSE HSG 39: Compressed Air Safety
•
OSHA Standards for General Industry 29 CFR 1910
o
1910.101 Compressed Gases (General Requirements)
o
1910.102 Acetylene
o
1910.103 Hydrogen
o
1910.104 Oxygen
o
1910.105 Nitrous Oxide
o
1910.242(b) Compressed Air, Cleaning
o
1910.169 Compressed Air, Receiver
o
1910.253 Oxygen-fuel Gas Welding and Cutting

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CoP 49.0 – Compressed Gases and Air - Version 4.1 – 16th February 2026 Page 25 of 26
5. Document Amendment Record
Version Revision Date Description of Amendment
Page/s Affected
4.0
15th July 2024
System acronym updated from OSHAD-SF
to ADOSH-SF to accurately reflect
document title
Throughout
Change from OSHAD to ADPHC
Change of Logo
Minor editorial changes throughout the
document without changing requirements.
Title of Mechanism 7.0 updated to ADOSH-
SF – Mechanism 7– Occupational Safety
and Health Practitioner and Service
Provider Registration
OSHAD-SF - Mechanism 8.0 - OSH
Practitioner Registration deleted
4.1
16th February
2026
Updated definition of compressed gas
cylinder
3
Added clause 3.5(o)(vi)
13
Amended / updated clauses 3.3(c), 3.7(a),
3.7.1(b), (e), 3.7.2(o) and 3.10(a)
10, 15, 16, 21
Amended Clause 3.10(b) to better identify
testing standards of cylinder types
handled in the UAE
22
Minor editorial changes throughout the
document without changing requirements
Throughout