SSSTS Risk Assessment & Method Statement Review 3 — Questions and Answers
Question 1: What is the hierarchy of control measures, in order from most to least effective?
- Elimination, substitution, engineering controls, administrative controls, PPE (Correct answer)
- PPE, administrative controls, engineering controls, substitution, elimination
- Administrative controls, PPE, engineering controls, substitution, elimination
- Engineering controls, substitution, elimination, PPE, administrative controls
Correct answer: Elimination, substitution, engineering controls, administrative controls, PPE
The hierarchy of controls: Elimination (remove the hazard entirely), Substitution (replace with something less hazardous), Engineering controls (physical safeguards), Administrative controls (safe systems, training), and PPE (last resort personal protection). Most effective first.
Question 2: What does 'residual risk' mean after control measures have been applied?
- The remaining level of risk after all practicable control measures have been implemented (Correct answer)
- The risk before any controls are considered
- The risk that is transferred to subcontractors
- The risk that the HSE accepts
Correct answer: The remaining level of risk after all practicable control measures have been implemented
Residual risk is the risk that remains after all reasonably practicable control measures have been put in place. Some residual risk is unavoidable. The risk assessment must demonstrate that residual risk has been reduced to as low as reasonably practicable.
Question 3: Which tool is commonly used to evaluate risk by combining likelihood and severity scores?
- A risk matrix (risk rating table) (Correct answer)
- A Gantt chart
- A CPP checklist
- A toolbox talk record
Correct answer: A risk matrix (risk rating table)
A risk matrix combines numerical scores for likelihood (probability of harm occurring) and severity (consequence if harm occurs) to produce an overall risk rating. This helps prioritise which risks require the most urgent attention.
Question 4: What does 'dynamic risk assessment' mean?
- A continuous mental assessment of changing conditions carried out by workers during a task to identify new hazards that were not anticipated in the formal risk assessment (Correct answer)
- A risk assessment carried out at high speed
- A risk assessment using computer modelling
- A risk assessment updated after every accident
Correct answer: A continuous mental assessment of changing conditions carried out by workers during a task to identify new hazards that were not anticipated in the formal risk assessment
Dynamic risk assessment is the continuous, real-time process of recognising new or changed hazards during a task and responding appropriately. Workers and supervisors must constantly assess conditions as they change throughout the working day.
Question 5: What is the purpose of the 'record' step in the five-step risk assessment process?
- To document the significant findings so they can be communicated to workers and referred to if the assessment is challenged (Correct answer)
- Only to create paperwork for the site file
- To satisfy the HSE without taking any further action
- To record only the accidents that have occurred
Correct answer: To document the significant findings so they can be communicated to workers and referred to if the assessment is challenged
Recording the significant findings of a risk assessment is required for employers with five or more employees. The record communicates the hazards and controls to workers and provides evidence that a proper assessment was carried out if challenged.
Question 6: When is a 'dynamic risk assessment' particularly important on a construction site?
- When working conditions change unexpectedly — e.g., when unexpected ground conditions, weather changes or adjacent activities create new hazards (Correct answer)
- Only during the first week on a new site
- Only for work at height activities
- Only when formal risk assessments have not been completed
Correct answer: When working conditions change unexpectedly — e.g., when unexpected ground conditions, weather changes or adjacent activities create new hazards
Dynamic risk assessment is particularly important when site conditions change unexpectedly, such as deteriorating weather, discovery of unexpected underground services, changes in adjacent activities or any situation not covered by the formal risk assessment.
SSSTS Risk Assessment & Method Statement Review 3
What is the hierarchy of control measures, in order from most to least effective?