ACSA NCSO
(National Construction Safety Officer)
EXAM QUESTIONS
and Detailed Answers
This study guide contains original practice questions modeled on the topic areas
tested in the Alberta Construction Safety Association (ACSA) National Construction
Safety Officer (NCSO®) certification exam. Each question is immediately followed
by a detailed, in-depth answer to reinforce understanding rather than simple
memorization.
Topic areas covered:
• Hazard Assessment & Control
• Training & Worker Orientation
• Site Inspections
• Incident Investigations
• Health & Safety Program Auditing
• Documentation & Recordkeeping
• WHMIS (Workplace Hazardous Materials Information System)
• Adopted Standards & Legislation (OHS Act, Regulation, Code)
• First Aid & Emergency Preparedness
• Canadian Criminal Code (Bill C-45 / Section 217.1)
,Section 1: Hazard Assessment & Control
Q1. What is the difference between a hazard and a risk in the context of
construction safety?
Answer:
A hazard is any source, situation, or act with the potential to cause injury,
illness, or property damage — for example, an unguarded edge, exposed
rebar, or a rotating saw blade. Risk is the likelihood that a hazard will
actually cause harm, combined with the severity of the potential
consequence. In practical terms, a hazard exists whether or not anyone is
exposed to it, while risk only becomes meaningful once you consider
exposure, frequency, and probability of an incident occurring. An NCSO
must be able to identify hazards first, then evaluate the risk they pose so
that controls can be prioritized using the hierarchy of controls, starting with
the most effective measures (elimination and substitution) and working
down to the least effective (administrative controls and personal protective
equipment).
Q2. List and explain the hierarchy of hazard controls in the order they
should be applied.
Answer:
The hierarchy of controls, from most to least effective, is: (1) Elimination —
physically remove the hazard entirely, such as designing out a fall hazard
so work can be done from the ground. (2) Substitution — replace the
hazard with something less dangerous, such as swapping a solvent-based
adhesive for a water-based one. (3) Engineering controls — isolate
people from the hazard using physical means such as guardrails, machine
guards, or local exhaust ventilation. (4) Administrative controls • change
the way people work through procedures, training, signage, job rotation, or
scheduling to reduce exposure. (5) Personal protective equipment (PPE)
— the last line of defense, worn by the worker (hard hats, harnesses,
respirators). PPE is placed last because it depends on correct fit, consistent
use, and does not remove the hazard itself — if it fails or is used improperly,
the worker is directly exposed.
, Q3. Who is responsible for completing a Field Level Hazard
Assessment (FLHA), and when should it be done?
Answer:
The worker(s) who will actually be performing the task are responsible for
completing the FLHA, typically with input or review from a supervisor. It
should be completed before the task begins, at the start of each shift, and
again any time the scope of work, location, crew, equipment, or conditions
change significantly during the day (for example, weather changes, a new
piece of equipment is introduced, or the crew moves to a different area of
the site). The FLHA should identify the specific steps of the task, the
hazards associated with each step, and the controls that will be used, and it
should be signed by all workers involved to confirm they understand and
agree with the plan.
Q4. What is the purpose of a Job Hazard Analysis (JHA), and how does
it differ from an FLHA?
Answer:
A Job Hazard Analysis breaks a specific job or task down into its individual
steps, identifies the hazards associated with each step, and specifies the
controls required, and is generally developed in advance by a supervisor or
safety professional for recurring or higher-risk tasks (such as confined
space entry or crane lifts). It is a more formal, detailed, and pre-planned
document. An FLHA, by contrast, is completed by the workers themselves
on-site, immediately before the task, and is meant to be a quick, practical,
real-time check of current conditions. In many programs the JHA serves as
the reference document, and the daily FLHA is used to confirm that
conditions on the ground still match what the JHA assumed.
Q5. Explain the concept of 'imminent danger' and the actions a worker
or NCSO should take if it is identified.
Answer:
Imminent danger refers to a hazardous condition or practice that could
reasonably be expected to cause serious injury, illness, or death
immediately or before the hazard can be corrected through normal
procedures. Under Alberta OHS legislation, a worker has both the right and,
(National Construction Safety Officer)
EXAM QUESTIONS
and Detailed Answers
This study guide contains original practice questions modeled on the topic areas
tested in the Alberta Construction Safety Association (ACSA) National Construction
Safety Officer (NCSO®) certification exam. Each question is immediately followed
by a detailed, in-depth answer to reinforce understanding rather than simple
memorization.
Topic areas covered:
• Hazard Assessment & Control
• Training & Worker Orientation
• Site Inspections
• Incident Investigations
• Health & Safety Program Auditing
• Documentation & Recordkeeping
• WHMIS (Workplace Hazardous Materials Information System)
• Adopted Standards & Legislation (OHS Act, Regulation, Code)
• First Aid & Emergency Preparedness
• Canadian Criminal Code (Bill C-45 / Section 217.1)
,Section 1: Hazard Assessment & Control
Q1. What is the difference between a hazard and a risk in the context of
construction safety?
Answer:
A hazard is any source, situation, or act with the potential to cause injury,
illness, or property damage — for example, an unguarded edge, exposed
rebar, or a rotating saw blade. Risk is the likelihood that a hazard will
actually cause harm, combined with the severity of the potential
consequence. In practical terms, a hazard exists whether or not anyone is
exposed to it, while risk only becomes meaningful once you consider
exposure, frequency, and probability of an incident occurring. An NCSO
must be able to identify hazards first, then evaluate the risk they pose so
that controls can be prioritized using the hierarchy of controls, starting with
the most effective measures (elimination and substitution) and working
down to the least effective (administrative controls and personal protective
equipment).
Q2. List and explain the hierarchy of hazard controls in the order they
should be applied.
Answer:
The hierarchy of controls, from most to least effective, is: (1) Elimination —
physically remove the hazard entirely, such as designing out a fall hazard
so work can be done from the ground. (2) Substitution — replace the
hazard with something less dangerous, such as swapping a solvent-based
adhesive for a water-based one. (3) Engineering controls — isolate
people from the hazard using physical means such as guardrails, machine
guards, or local exhaust ventilation. (4) Administrative controls • change
the way people work through procedures, training, signage, job rotation, or
scheduling to reduce exposure. (5) Personal protective equipment (PPE)
— the last line of defense, worn by the worker (hard hats, harnesses,
respirators). PPE is placed last because it depends on correct fit, consistent
use, and does not remove the hazard itself — if it fails or is used improperly,
the worker is directly exposed.
, Q3. Who is responsible for completing a Field Level Hazard
Assessment (FLHA), and when should it be done?
Answer:
The worker(s) who will actually be performing the task are responsible for
completing the FLHA, typically with input or review from a supervisor. It
should be completed before the task begins, at the start of each shift, and
again any time the scope of work, location, crew, equipment, or conditions
change significantly during the day (for example, weather changes, a new
piece of equipment is introduced, or the crew moves to a different area of
the site). The FLHA should identify the specific steps of the task, the
hazards associated with each step, and the controls that will be used, and it
should be signed by all workers involved to confirm they understand and
agree with the plan.
Q4. What is the purpose of a Job Hazard Analysis (JHA), and how does
it differ from an FLHA?
Answer:
A Job Hazard Analysis breaks a specific job or task down into its individual
steps, identifies the hazards associated with each step, and specifies the
controls required, and is generally developed in advance by a supervisor or
safety professional for recurring or higher-risk tasks (such as confined
space entry or crane lifts). It is a more formal, detailed, and pre-planned
document. An FLHA, by contrast, is completed by the workers themselves
on-site, immediately before the task, and is meant to be a quick, practical,
real-time check of current conditions. In many programs the JHA serves as
the reference document, and the daily FLHA is used to confirm that
conditions on the ground still match what the JHA assumed.
Q5. Explain the concept of 'imminent danger' and the actions a worker
or NCSO should take if it is identified.
Answer:
Imminent danger refers to a hazardous condition or practice that could
reasonably be expected to cause serious injury, illness, or death
immediately or before the hazard can be corrected through normal
procedures. Under Alberta OHS legislation, a worker has both the right and,
