NEBOSH IOG Exam : Element 1 |
questions and verified answers
A worker has been hit by a reversing vehicle in a loading bay. Identify possible immediate
causes and root causes. - ANSWER Immediate causes:
The audible reverse indicator sound on the vehicle was not functioning (unsafe condition)
Lighting in the area was not sufficient (unsafe condition)
The driver was driving too fast (unsafe act)
Root Cause:
Lack of maintenance on the vehicle
Work area not properly planned for low light conditions
Lack of Driver Training and/or refresher training
Breaking of rules and regulations (speed limits)
Give the meaning of the terms Lower and Upper Flammability Limits - ANSWER Lower
Flammability Limits (LFL or LEL - Lower Explosive Limits) is the minimum concentration level
of fuel in air that is sufficient to allow combustion to occur. Below LFL/LEL the mixture is
too lean to burn). The Upper Flammability Limit (UFL or UEL) is the maximum concentration
of fuel in air that is sufficient to allow combustion to occur. Above the UFL the mixture is
too rich to burn. Between these limits is the explosive range.
Outline which are the four elements common to health & safety as well as general,
management systems - ANSWER Plan - implies having a considered policy
Do - concerns the arrangements for putting the plan into practice
Check - means it is necessary to assess or monitor performance
Act - means performance should be reviewed leading to continuous improvement in the
management system
, Outline the four main areas of risk to be dealt with in oil and gas processing risk control -
ANSWER The four main areas of risk are: (4P's)
Production Workplace - the field or rig and its associated facilities and support systems; safe
access and egress; work environment; welfare facilities and accommodations; pipelines and
structures; and electrical and communications installations.
Plant & Substances - the drilling and pumping and transportation systems of the O&G;
how the O&G are stored and handled; and all materials in use at the process area.
Procedures - organisation procedures such as work and shift patterns; job design and the
way work is done (and managed)
People - management and leadership; competence and placement of workers; training
and health surveillance necessary
In risk control barrier models (e.g. bowtie), explain what criteria are placed between
the barriers, and what are the barriers called. - ANSWER In a bowtie diagram, barriers
are normally placed between the initiating event and the release, and the release and
its consequences.
The barriers are placed to prevent, control or mitigate the outcome of the event and
are known as Lines of Defence (LOD) or Layers of Protection (LOP)
Give the meaning of the term "flash point" - ANSWER The lowest temperature at
which there is sufficient vaporisation of a substance capable of producing a flash
momentarily when a source of ignition is applied.
Give the meaning of the term "vapour density" - ANSWER (Mass of vapour per unit volume)
Density of the vapour relative to the air. It indicates whether a flammable vapour is likely to
rise in the air or, more commonly, sink and accumulate in low-lying areas. If VD greater than
1, the vapour is heavier than air and will sink.
questions and verified answers
A worker has been hit by a reversing vehicle in a loading bay. Identify possible immediate
causes and root causes. - ANSWER Immediate causes:
The audible reverse indicator sound on the vehicle was not functioning (unsafe condition)
Lighting in the area was not sufficient (unsafe condition)
The driver was driving too fast (unsafe act)
Root Cause:
Lack of maintenance on the vehicle
Work area not properly planned for low light conditions
Lack of Driver Training and/or refresher training
Breaking of rules and regulations (speed limits)
Give the meaning of the terms Lower and Upper Flammability Limits - ANSWER Lower
Flammability Limits (LFL or LEL - Lower Explosive Limits) is the minimum concentration level
of fuel in air that is sufficient to allow combustion to occur. Below LFL/LEL the mixture is
too lean to burn). The Upper Flammability Limit (UFL or UEL) is the maximum concentration
of fuel in air that is sufficient to allow combustion to occur. Above the UFL the mixture is
too rich to burn. Between these limits is the explosive range.
Outline which are the four elements common to health & safety as well as general,
management systems - ANSWER Plan - implies having a considered policy
Do - concerns the arrangements for putting the plan into practice
Check - means it is necessary to assess or monitor performance
Act - means performance should be reviewed leading to continuous improvement in the
management system
, Outline the four main areas of risk to be dealt with in oil and gas processing risk control -
ANSWER The four main areas of risk are: (4P's)
Production Workplace - the field or rig and its associated facilities and support systems; safe
access and egress; work environment; welfare facilities and accommodations; pipelines and
structures; and electrical and communications installations.
Plant & Substances - the drilling and pumping and transportation systems of the O&G;
how the O&G are stored and handled; and all materials in use at the process area.
Procedures - organisation procedures such as work and shift patterns; job design and the
way work is done (and managed)
People - management and leadership; competence and placement of workers; training
and health surveillance necessary
In risk control barrier models (e.g. bowtie), explain what criteria are placed between
the barriers, and what are the barriers called. - ANSWER In a bowtie diagram, barriers
are normally placed between the initiating event and the release, and the release and
its consequences.
The barriers are placed to prevent, control or mitigate the outcome of the event and
are known as Lines of Defence (LOD) or Layers of Protection (LOP)
Give the meaning of the term "flash point" - ANSWER The lowest temperature at
which there is sufficient vaporisation of a substance capable of producing a flash
momentarily when a source of ignition is applied.
Give the meaning of the term "vapour density" - ANSWER (Mass of vapour per unit volume)
Density of the vapour relative to the air. It indicates whether a flammable vapour is likely to
rise in the air or, more commonly, sink and accumulate in low-lying areas. If VD greater than
1, the vapour is heavier than air and will sink.
