NEBOSH-IOG Examiners Feedback-pdf

NEBOSH

International Technical Certificate in Oil and Gas Operational Safety
Unit IOG1: Management of international oil and gas operational safety

Examiners’ feedback*

*Feedback for the NEBOSH example Oil and Gas question paper (downloadable from the NEBOSH website),
and the sample question paper from the NEBOSH guide.
Other examiners’ reports can be purchased from the NEBOSH shop.

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context

exam question

Risk management tools and techniques are used to minimise hazardous events
associated with oil and gas exploration and production activities.

(a) Identify risk management tools and techniques. 6 marks

(b) Identify the steps of risk management AND 8 marks
outline EACH of the steps identified.

(c) Identify project phases where risk management 6 marks
applies.

answer expected by examiners

(a) Suitable tools and techniques include:
 bow-tie analysis
 hazard and operability studies (HAZOP)
 Swiss cheese model
 job hazard analysis (JHA)
 fault tree analysis (FTA)
 failure modes effects analysis (FMEA)
 hazard realisation.

(b) The steps of risk management are as follows.
 Identifying hazards – an outline of a range of hazards is required.
 Evaluating risk – an outline of determining the acceptability of a specific risk
is required.
 Risk reduction measures – an outline of mitigating measures, setting
functional requirements and necessary risk reduction measures is required.
 Review – an outline of a review is required.

(c) Suitable phases include:
 design
 construction
 commissioning
 start-up
 shut down
 decommissioning.

© Astutis Ltd NEBOSH IOGC 2
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Element 1: Health, safety and environmental management in context
exam question

Outline the following terms. 2 marks
(a) Upper flammable limit (UFL). 2 marks
(b) Lower flammable limit (LFL). 2 marks
(c) Flashpoint. 2 marks
(d) Highly flammable liquids.

answer expected by examiners

(a) The highest concentration of a flammable substance in air that will ignite when
exposed to an ignition source. Above the UFL the mixture is too rich to burn.

(b) The lowest concentration of a flammable substance in air that will ignite when
exposed to an ignition source. Below the LFL the mixture is too lean to burn.

(c) The minimum temperature to which a material must be heated for the vapours
emitted to ignite in the presences of a flame.

(d) Substances which remain liquid under pressure and having a flashpoint lower than
21°C.

© Astutis Ltd NEBOSH IOGC 3
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Element 1: Health, safety and environmental management in context
exam question

Many major oil/gas incidents have occurred in recent years, for example, Texas City,
Mumbai High.

(a) Outline FOUR reasons why such incidents should be 4 marks
investigated by employers.

(b) Identify FOUR parties, other than the employer, who 4 marks
may want to investigate these types of incident.

answer expected by examiners

(a) Reasons include:
 preventing re-occurrence
 meeting legal requirements
 gathering evidence to defend against legal action
 determining costs.

(b) Interested parties include:
 the local authority
 the police
 the coroner
 insurance companies.

© Astutis Ltd NEBOSH IOGC 4
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Element 1: Health, safety and environmental management in context
exam question

(a) Identify the hazardous properties of liquid petroleum gas (LPG). 4 marks

(b) Outline the risks associated with liquid petroleum gas (LPG). 4 marks

answer expected by examiners

(a) The hazardous properties of LPG include:
 low temperature
 it is a gas at normal temperature and pressure
 it is colourless and odourless
 readily liquefied under pressure
 LPG is highly flammable
 it is a fuel gas
 reacts explosively with chlorine.

(b) The risks associated with LPG include:
 the potential for cylinders to form a BLEVE
 that it is denser than air and collects at low level, in drains & sewers creating a risk of fire
& explosion
 that it readily forms an explosive mixture with air
 that in weak concentrations can be easily ignited flashing back to the source of
a leak
 that inhalation can lead to drowsiness and that it is an asphyxiant
 that contact with cold pipework can cause frost burns
 that cylinders may create a manual handling risk.

© Astutis Ltd NEBOSH IOGC 5
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Element 1: Health, safety and environmental management in context
exam question

Safety cases and safety reports provide documented evidence that an oil and gas
installation is safe.

Outline the typical content of these types of documents. 8 marks

answer expected by examiners

The typical content of these documents includes:

 Identification of major accident hazards through risk assessment (Q, SQ, QRA), bow-
tie diagrams, information from previous operations and incident reports and input
from design drawings and calculations.

 Evaluation of major accident risks and the measures in place, or to be introduced, to
control such risks. This will detail all existing ‘designed-in’ precautions and safety
measures, and reference into previous or existing risk controls.

 Arrangements for auditing and audit reporting setting out a schedule of the type and
frequency of auditing, locations to be covered, how the audit will be conducted,
reporting mechanisms for recommendations, arrangements for monitoring
completion of action plans and overall responsibility for their completion.

 Safety management system in place, including controls for the management of
contractor, and sub-contractor personnel and activities.

 Major accident prevention policies that are in place to support the safety
management system and vice versa.

 Identification of safety critical elements in place to manage major accident hazards –
scenarios, possible causes, preventative/mitigating controls and recovery systems.

 Details of emergency plans including plans of the installation detailing locations of
emergency and safety equipment, location of control room or points, isolation and
shutdown controls, safe access and escape routes, access to and arrangements for
crewing rescue boats and their launch procedures.

© Astutis Ltd NEBOSH IOGC 6
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Element 1: Health, safety and environmental management in context
exam question

An employee was seriously injured in an accident at work within an oil and gas installation.

Identify the documented information that might be used by the 8 marks
investigating team to determine the causes of this accident.

answer expected by examiners

The documented information that might be used includes the following.
 Company health & safety policy.
 RIDDOR reports (if UK).
 Riskassessments&methodstatements.
 Training records.
 Safe systems of work.
 Permits-to-work.
 Maintenance records.
 Disciplinary records.
 Internal accident report forms.
 Log book entries.
 Computer records/printouts relevant to the situation.
 Diagrams, pictures and sketches of the area.
 Environmental & weather conditions/records.

© Astutis Ltd NEBOSH IOGC 7
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Element 2: Hydrocarbon process safety 1
exam question

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4 marks
(b) Outline the benefits of a standard operating procedure. 2 marks

(c) Describe the style in which a standard operating procedure
should be written to aid understanding.

answer expected by examiners

(a) A sequenced set of written instructions that is accessible to workers.

(b) Benefits include:
 the promotion of operational quality
 minimising variation between workers
 compliance with government procedures
 provision of a reference source for modifications of plant.

(c) The procedures should be unambiguous.

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Element 2: Hydrocarbon process safety 1
exam question

Within an oil and gas production platform, effective shift handovers can prevent incidents.

Outline practical operational issues that should be communicated 8 marks
at shift handover.

answer expected by examiners

Issues to be communicated include:

 an update on ongoing permits
 any issues with process over previous days
 a physical demonstration of plant isolations
 any overrides on instrumentation
 any instances of plant going out of commission
 any ongoing trials
 the preparation of relevant documentation
 any abnormal events during the shift.

© Astutis Ltd NEBOSH IOGC 9
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Element 2: Hydrocarbon process safety 1
exam question

Outline fire precautions that may be included in a hot work permit. 8 marks

answer expected by examiners

Precautions include:

 the provision of a standby / fire watcher
 the isolation of flammable services
 the removal of combustible material
 having fire-fighting equipment available
 gas cylinders being fitted with regulators and flashback arrestors
 wearing of fire resistant PPE.

© Astutis Ltd NEBOSH IOGC 10
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Element 2: Hydrocarbon process safety 1
exam question

Many serious accidents or incidents, including the Piper Alpha disaster in 1988, involve
root causes associated with shift handover.

An outgoing operator is handing over to an incoming operator at the end of a shift.

(a) Explain the key principles of safe shift handover. Information 10 marks
on specific operational issues is not required in part a.

(b) Outline the main operational issues communicated at shift 10 marks
handover.

answer expected by examiners

(a) The key principles of safe shift handover are to:

 make communication effectiveness at shift change-over a high priority
 include communication skills in the selection criteria for shift workers and train all

staff to communicate well
 conduct handovers face-to-face with staff from both shifts taking part
 ensure communication is two-way, using questions to confirm understanding
 ensure all forms of communication use unambiguous language
 ensure BOTH parties (on-coming and off-going crews) take joint responsibility for

making all information accurate, using both verbal and written communication
 place an emphasis on written communication
 base all information communicated at handover on a pre-determined analysis of

what detail the incoming shift need to have, consider using a pre-determined

format/structure
 use structured headings in hand-over reports and logs
 ensure good operator support, by the use of shift-logs, maintenance records,

information displays, etc. all based on operators' needs
 take ideas for required information and effective information transfer from the

shift-teams, so they can then ensure they get the information they need
 allow as much time as is necessary to ensure that communication is accurate and

understood.

continued on next page …

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(b) The main operational issues communicated at shift hand-over include:
 the operational status of the installation or process
 what maintenance operations have been carried out and completed
 what maintenance issues have begun but NOT been completed
 clearance of permits-to-work
 hand-over of permits-to-work still open
 situations where safety systems have been overridden (e.g. fire deluge
system switched to manual operation)
 deviations from normal working, such as breakdowns or lack of spare parts
or replacement equipment
 emergencies that may have occurred during the shift
 incidents or injuries following accidents during the shift
 what operational issues will occur in the on-coming shift, routine & non
routine
 what maintenance operations are planned during the on-coming shift
 what events (drills or exercises) are planned during the on-coming shift
 the absence/availability of key personnel knowledgeable in specific tasks
 any isolations that are in place or to be removed.

© Astutis Ltd NEBOSH IOGC 12
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Element 2: Hydrocarbon process safety 1 8 marks
exam question

Outline FOUR types of work activity associated with an oil
platform that might require a permit-to-work AND give a reason in
EACH case for the requirement.

answer expected by examiners

 Hot work — welding, burning, grinding, etc. because such work might provide a
source of ignition in the presence of fuels, leading to fire. It ensures adequate fire
precautions are taken during and after the work.

 Live or high voltage work — to ensure competent (electrical) employees, correct
safe isolation and live working procedures are followed, safe equipment and tools
used, etc. as appropriate.

 Working at height — to ensure that a proper safe working at height plan is followed,
safe systems of work are followed, safe equipment used and rescue facilities are in
place where appropriate.

 Working over water — to ensure that appropriately trained operatives are
employed, together with all adequate precautions, such as life preservers, rescue
boats, etc. being in place.

 Work in confined spaces — to ensure adequate safe entry precautions are taken, air
monitoring where appropriate, use of safe tools and equipment (especially in what
may be flammable or explosive atmospheres); safe isolation is ensured and rescue
arrangements in place to recover persons.

 Special maintenance permits — where maintenance is of particularly high risk, or
conditions such that very close control must be maintained, especially where a shift
system may change during the work being carried out.

 Simultaneous operations — to ensure the interactions, hazards & risk implications
of a number of activities that are to be carried out at the same time are controlled &
scheduled to minimize risk.

© Astutis Ltd NEBOSH IOGC 13
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Element 2: Hydrocarbon process safety 1
exam question

A large oil company is proposing to build a new oil and gas installation in the North Sea. The
Process Safety Management Team is analysing past incidents and database records from the
Oil and Gas Industry.

Excluding active and passive fire protection systems, outline physical 8 marks
design features of the platform that would minimise risk to operating
personnel in the event of a major incident.

answer expected by examiners

Suitable design features would include the following.

 Strength and integrity of main structural features.
 Spacing & segregation of operating plant, so that one fire cannot affect all units in

operation (e.g. storage vessels, item of plant, drilling floor, unloading facility).
 Isolating critical areas from non-critical areas so that a single fire in a non-critical area

cannot adversely affect performance or operation in any other areas.
 Positioning and protection of control rooms.
 Positioning and protection of critical equipment, including electrical supplies.
 Positioning and protection of occupied areas, particularly accommodation and welfare areas.
 Provision and protection of temporary refuges.
 Positioning safety critical areas are away from high risk areas, such as process and storage and

processing of flammable materials away from control rooms, fire control systems and

accommodation.
 Consideration to both positioning & protection of above or below hazardous areas, as well as

beside them on the same level.
 Protection includes structures built of materials that are adequately fire resistant and

blast resistant.
 Having heating, ventilation and air conditioning that can be self-sustaining and

continue in operation throughout hazardous events.
 Positioning & protection of escape equipment, with safe routes, refuges and access to

evacuation and rescue craft from within protected areas.

© Astutis Ltd NEBOSH IOGC 14
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exam question

Outline the content of a procedure for bypassing an emergency
shutdown (ESD) system.

answer expected by examiners

A suitable procedure should include:
 assessment of alternative levels of protection
 ensuring senior level authorisation for the bypass
 defining the bypass period and time bounding
 having clear radio communication during the bypass
 informing supervisors
 logging actions in operator’s log book
 uniquely identifying the ESD to be bypassed
 using a dedicated log book for ESD bypasses.

© Astutis Ltd NEBOSH IOGC 15
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Element 3: Hydrocarbon process safety 2
exam question

The diagram below shows a typical arrangement for receiving a pipeline inspection
gauge (PIG). A pressure gauge (P) and a PIG detector (D) exist within the receiver/trap.
The detector (D) confirms that the PIG has been received in the trap, having earlier been
launched upstream at high pressure.

Main line flow

Main line isolating By-pass valve C Vent valve E
valve A PIG Door
PD
Main line flow
PIG receiver/trap

PIG receiver
isolating valve B

Drain valve D

(a) Outline the functions of a PIG. 4 marks

(b) Using the information and diagram above:
(i) identify TWO valves that must be closed before removing the 2 marks
PIG from the door
(ii) identify TWO valves that must be open before removing the PIG 2 marks
from the door.

answer expected by examiners

(a) Functions include:
 cleaning
 facilitating hydro-testing
 relaying information
 plugging of pipelines.

(b) (i) Valve B and valve C.
(ii) Valve E and valve D.

© Astutis Ltd NEBOSH IOGC 16
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Element 3: Hydrocarbon process safety 2
exam question

In relation to weld failures: 2 marks
2 marks
(a) give the meaning of the term ‘non-destructive testing’ 2 marks
(NDT) 2 marks

(b) identify TWO NDT techniques that detect surface defects
only

(c) identify TWO NDT techniques that detect sub-surface
defects

(d) outline disadvantages of visual inspection techniques.

answer expected by examiners

(a) Testing of a material for defects/cracks, without affecting the integrity of the
material.

(b) Dye penetrant and visual techniques.
(c) Eddy current and radiography.
(d) Only surface defects are detected and surfaces need to be clean.

© Astutis Ltd NEBOSH IOGC 17
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Element 3: Hydrocarbon process safety 2
exam question

Outline the following failure modes that may lead to loss of hydrocarbon containment from
storage tanks/vessels or pipelines.

(a) Creep. 2 marks

(b) Stress corrosion cracking. 2 marks

(c) Thermal shock. 2 marks

(d) Brittle fracture. 2 marks

answer expected by examiners

(a) Creep — the gradual extension of material under a steady tensile stress, typically
over a long period of time. It occurs in stages known as primary or transient creep,
secondary creep and tertiary creep. Creep is usually important at high temperatures.

(b) Stress corrosion cracking — occurs when there is a susceptible material, a
corrosive environment and enough tensile stress to induce the cracking.

(c) Thermal shock — the effect of cracking that results from rapid and extreme
temperature changes when a thermal gradient causes different parts of an object
to expand by different amounts, causing uneven expansion and cracking to occur.

(d) Brittle fracture — occurs very suddenly and without warning, allowing a rapid
release of energy. It occurs because the structure of the material does not slip, so
small cracks appear throughout so quickly that a massive failure is produced,
often promoted by low temperatures.

© Astutis Ltd NEBOSH IOGC 18
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Element 3: Hydrocarbon process safety 2 2 marks

exam question 4 marks
2 marks
(a) Identify TWO ways in which vapour clouds can be
generated.

(b) Outline how a vapour cloud explosion can be generated.
(c) Identify the physical consequences of vapour cloud

explosions.

answer expected by examiners

(a) Vapour clouds may be generated by:
 overfilling or overflowing of a tank or vessel causing a release of
hydrocarbon fuels
 fracture or failure of the tank, vessel or pipework causing a release of hydrocarbon
fuels
 splash filling of tanks or vessels.

(These may occur at an outdoor vessel, which will create an unconfined vapour

cloud, or within a tank or building, creating a confined vapour cloud.)

(b)  A flammable vapour must be present
 The vapour air concentration must between the upper and lower
explosive limits.
 An ignition source that exceeds the minimum ignition energy is required
to ignite the vapour.
 A vapour cloud explosion may be confined e.g. in a tank or vessel or
unconfined e.g. outside.
 Unconfined vapour clouds may travel a considerable distance before
igniting or they may be dispersed to a concentration below the lower
explosive limit depending on conditions.

(c)  Thermal radiation & heat from the resultant fireball.
 Blast/pressure wave produced.
 The impact & damage caused by fragments, debris, equipment and materials
being propelled by the blast wave.

© Astutis Ltd NEBOSH IOGC 19
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Element 3: Hydrocarbon process safety 2
exam question

An operator is draining a flammable liquid from process pipework to a metal container.
The supervisor is concerned about the possibility of an electrostatic charge forming and
stops this operation until a risk assessment is undertaken. During this work activity:

(a) identify factors that influence the generation of the 4 marks
electrostatic charge 4 marks

(b) outline practical ways of minimising the formation of an
electrostatic charge.

answer expected by examiners

(a) Potential factors include the following.
 The flow rate of flammable liquids inside a pipe or vessel can build up
static electricity.
 The conductivity of the materials being used, including that of the liquid,
pipework & containers.
 Surface or contact area, e.g. use of filters increase surface area for friction
& the generation of a charge.
 Presence of impurities or mixtures of product e.g. solids, water &
dissimilar liquids that don’t dissolve within each other
 Turbulence caused by large flow rates, mixing/stirring & splash filling.

(b) Practical solutions include the following.
 Good earthing and bonding of all parts of the system e.g. from process
pipework to the metal container
 The addition of additives to increase conductivity of the liquid.
 Reduce, minimise, & control flow rates.
 Avoid splash filling by using dip tubes & bottom filling.
 Ensure operatives wear conductive (anti-static) clothing/PPE.
 Avoid unnecessary filtering or install filters upstream of the discharge
points to allow any static charge to be dissipated before reaching the
discharge point.

© Astutis Ltd NEBOSH IOGC 20
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exam question

(a) Petroleum storage tank fires have been substantially 4 marks
reduced by using floating roofs but a fire risk may still exist. 2 marks

(i) Outline how a fire risk may still exist with floating roof 2 marks
tanks.

(ii) Identify TWO examples of a fire protection system used
on floating roof tanks.

(b) Process modules in an oil and gas installation often contain
computer rooms that require fire protection.

Identify TWO examples of fire extinguishing media that
could be used in a computer room.

answer expected by examiners

(a) (i) Fire risk may still exist due to:
 the roof sinking if there is insufficient water drainage
 the annular seal failing
 ignition through static electricity.

(ii) Suitable fire protection systems include:
 foam-based types
 over the top systems
 chemical types, such as Du Pont FE36.

(b) Suitable fire extinguishing media include:
 CO2
 water mist
 inert gas.

© Astutis Ltd NEBOSH IOGC 21
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Element 4: Fire protection and emergency response
exam question

An oil installation contains a vessel that requires protection from fire exposure in the form of
active or passive fire protection.

(a) Identify TWO examples of passive fire protection to protect 2 marks
vessels.

(b) Outline why the metal legs of the vessel should be protected. 2 marks

(c) Outline how a fixed water deluge system could provide fire 2 marks
protection.

(d) Identify TWO additional examples of active fire protection. 2 marks

answer expected by examiners

(a) Suitable passive fire protection could be provided by:
 spray-applied coating, such as, cement-based plaster coatings and spray-
applied epoxy-based intumescent (expands under fire conditions) coatings
 mineral wool/fibre jacket or lagging
 earth mounds (burying the vessels beneath the ground)
 physical fire barriers/walls between potential fire sources and the vessel.

(b) The metal legs of a vessel should be protected because, if they are not, they will
heat up, expand, lose their strength and fail, losing their structural load-bearing
capability (this happens over around 400°C for steel and around 200°C for
aluminium). This will cause the vessel to topple and potentially rupture, escalating
any fire.

(c) A fixed water deluge system could provide fire protection by:
 directly cooling the vessel, providing the high spray rate and the volume of
water needed to cover the large surface area of the vessel
 providing a water curtain between the fire and the vessel, reducing the
transmission of radiated heat.

(d) Additional example of active fire protection include:
 fire/foam sprinkler installations
 gaseous inerting systems (using carbon dioxide or nitrogen)
 water mist systems, water/foam monitors and hoses
 dry chemical fixed installations
 portable fire extinguishers.

© Astutis Ltd NEBOSH IOGC 22
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exam question

Identify EIGHT marine hazards associated with all types of floating 8 marks
production, storage and offloading units (FPSOs).

answer expected by examiners

Marine hazards associated with FPSOs include:
 extreme weather conditions
 long term exposure to environmental conditions
 additional motions/stresses from a ship-like structure
 wave loading against the ship
 operational hazards of unloading
 anchoring failures
 collisions with passing supply vessels.

© Astutis Ltd NEBOSH IOGC 23
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Element 5: Logistics and transport operations
exam question

(a) Identify THREE marine hazards associated with all types of 3 marks
floating platform storage and offloading units (FPSOs). 5 marks

(b) Identify suitable controls that minimise risk when operating
floating platform storage and offloading units (FPSOs).

answer expected by examiners

(a) Marine hazards associated with FPSOs are:
 extreme environment such as high winds and storms, which may cause the
vessel to cut loose from its mooring or damage the structure
 accelerated corrosion and wear (from the constant buffeting of the sea and the
nature of salt spray), which may cause vessel failure and loss of containment
(and also potential fire, explosion and environmental damage)
 proximity of other vessels and risk of collisions
 slippery surfaces resulting in slips, trips and falls , and the potential for people
falling overboard
 cargo transfer operations, potential for spills, and transfer of stores and
equipment
 sabotage, piracy and other security-related issues
 diving operations in the vicinity of the vessel.

(b) Suitable controls to minimise risks include:
 selection and certification of the vessel (in terms of design class to withstand the
likely conditions and stresses)
 design strength of moorings (to withstand likely conditions)
 inspection and maintenance regime for the vessel, transfer equipment and
moorings
 co-ordination of proximal activities (such as nearby tanker vessel movements)
and having an exclusion zone around the FPSO ( to exclude for example fishing
vessels)
 safe personnel transfer methods (for example, bridges)
 control over diving operations (permit-to-dive)
 consideration of security provision to deter or react to piracy.

© Astutis Ltd NEBOSH IOGC 24
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