CHST Incident Investigation and Reporting 5 — Questions and Answers
Question 1: Which element of the incident causation model represents conditions that allow or fail to prevent an unsafe act?
- Immediate cause
- Contributing cause
- Systemic root cause
- Precondition or enabling factor (Correct answer)
Correct answer: Precondition or enabling factor
Preconditions or enabling factors (sometimes called indirect causes) are environmental, organizational, or individual conditions that set the stage for unsafe acts to occur.
Question 2: A construction crew foreman witnesses a near-miss and decides not to report it to avoid paperwork. What systemic problem does this MOST likely reflect?
- Inadequate personal protective equipment
- A punitive or blame-focused safety culture (Correct answer)
- Insufficient training on equipment operation
- Poorly designed engineering controls
Correct answer: A punitive or blame-focused safety culture
Failure to report near-misses is a classic symptom of a punitive safety culture where workers fear reprisal; a just culture encourages reporting without blame.
Question 3: In a fault tree analysis (FTA) of a scaffold collapse, an AND gate means that:
- Either of the linked events alone can cause the top event
- All linked events must occur simultaneously for the outcome to result (Correct answer)
- Only the most likely event needs to be addressed
- The sequence of events is irrelevant to the outcome
Correct answer: All linked events must occur simultaneously for the outcome to result
An AND gate in FTA indicates that the output event occurs only when ALL of the input events occur simultaneously, making it useful for identifying compound failure modes.
Question 4: Which of the following BEST describes a 'contributing cause' in incident investigation terminology?
- The single root cause that directly triggered the incident
- A condition that alone would not cause the incident but increased its likelihood or severity (Correct answer)
- An act of God or uncontrollable environmental factor
- The regulatory violation cited by the OSHA inspector
Correct answer: A condition that alone would not cause the incident but increased its likelihood or severity
Contributing causes are factors that increase the probability or severity of an incident but are insufficient on their own to cause it without the presence of other causes.
Question 5: An OSHA 301 Incident Report form must be completed within how many calendar days of a recordable work-related injury or illness?
- 24 hours
- 3 calendar days
- 7 calendar days (Correct answer)
- 30 calendar days
Correct answer: 7 calendar days
29 CFR 1904.29 requires employers to complete the OSHA 301 (or an equivalent form) within 7 calendar days of receiving information that a recordable case occurred.
Question 6: Which investigative technique involves systematically retracing an event sequence using boxes representing events connected by logic gates to identify all failure paths?
- Management oversight and risk tree (MORT)
- Fault tree analysis (FTA) (Correct answer)
- Job hazard analysis (JHA)
- Scatter diagram analysis
Correct answer: Fault tree analysis (FTA)
Fault tree analysis uses a top-down, deductive logic diagram with AND/OR gates connecting event boxes to identify every combination of failures that could lead to a defined undesired event.
Question 7: When photographing an incident scene, the RECOMMENDED sequence is to photograph:
- Close-up details first, then mid-range, then the overall scene
- The overall scene first, then mid-range, then close-up details (Correct answer)
- Only damaged equipment and injured personnel
- Whatever the OSHA compliance officer requests first
Correct answer: The overall scene first, then mid-range, then close-up details
Standard forensic photography protocol captures wide-angle orientation shots first to establish context, then progressively moves to mid-range and finally close-up detail shots.
CHST Incident Investigation and Reporting 5
Which element of the incident causation model represents conditions that allow or fail to prevent an unsafe act?