Additional Duty Safety Course (ADSC) Exam
Comprehensive Practice Exam – 300 Questions with
Answers, Choices, and Rationales
SECTION 1: THE HEINRICH MODEL AND ACCIDENT CAUSATION (Questions 1–20)
1. The Heinrich Model is best described as which of the following?
A) A financial model for safety budgeting
B) A model that explains the relationship between near misses, minor injuries, and major
accidents
C) A model for predicting equipment failure rates
D) A model for calculating insurance premiums
Answer: B) A model that explains the relationship between near misses, minor injuries, and
major accidents
Rationale: The Heinrich Model, also known as the safety triangle, posits that for every major
accident, there are 29 minor injuries and 300 near misses. This model emphasizes that
reducing near misses and minor incidents will lead to a reduction in major accidents.
2. Complete this sentence: "System defects are..."
A) Failures in individual employee performance
B) Weaknesses in the way the system is designed or operated
C) Errors caused by inadequate training only
D) Problems that cannot be corrected
Answer: B) Weaknesses in the way the system is designed or operated
Rationale: System defects refer to weaknesses in the way the system is designed or operated.
This concept is central to the Heinrich Model, which recognizes that accidents are often caused
by systemic issues rather than solely individual failures.
3. According to the Heinrich Model, what is the relationship between near misses and major
accidents?
A) Near misses are unrelated to major accidents
B) Near misses are precursors to major accidents
C) Major accidents cause near misses
D) Near misses only occur in high-risk industries
,Answer: B) Near misses are precursors to major accidents
Rationale: The Heinrich Model establishes that near misses are precursors to major accidents.
By addressing near misses, organizations can prevent more severe incidents from occurring.
4. Historically, accidents account for approximately what percentage of all U.S. Army casualties?
A) 10%
B) 30%
C) 50%
D) 70%
Answer: B) 30%
Rationale: Historically, accidents account for approximately 30% of all U.S. Army casualties.
This statistic underscores the importance of accident prevention within the Army Safety
Program.
5. The Heinrich Model suggests that reducing which type of incident will lead to a reduction in
major accidents?
A) Only major accidents
B) No-injury incidents and near misses
C) Equipment failures only
D) Only minor injuries
Answer: B) No-injury incidents and near misses
Rationale: Heinrich's theory suggests that a reduction in no-injury incidents (near misses) would
lead to a reduction in minor injury incidents and in major injury incidents.
6. Which of the following best describes the purpose of the Heinrich Model in safety
management?
A) To assign blame for accidents
B) To predict and prevent safety incidents
C) To calculate workers' compensation costs
D) To replace risk management processes
Answer: B) To predict and prevent safety incidents
Rationale: The Heinrich Model is used to analyze, predict, and prevent safety incidents by
focusing on the relationship between near misses, minor injuries, and major accidents.
,7. How does the Heinrich Model support the implementation of risk management?
A) By providing a framework for understanding accident causation
B) By eliminating the need for hazard identification
C) By replacing the need for safety training
D) By focusing only on major accidents
Answer: A) By providing a framework for understanding accident causation
Rationale: The Heinrich Model provides a framework for understanding how accidents are
caused, supporting risk management by emphasizing the importance of addressing
lower-severity incidents and near misses to prevent major accidents.
8. In the Heinrich Model, what is the ratio of major accidents to minor injuries to near misses?
A) 1:10:100
B) 1:29:300
C) 1:50:500
D) 1:100:1000
Answer: B) 1:29:300
Rationale: The Heinrich Model, often depicted as a triangle or pyramid, establishes the ratio of 1
major accident to 29 minor injuries to 300 near misses.
9. What is the primary implication of the Heinrich Model for safety professionals?
A) Only major accidents require investigation
B) Near misses should be ignored
C) Addressing near misses and minor incidents can prevent major accidents
D) Safety resources should be focused solely on catastrophic events
Answer: C) Addressing near misses and minor incidents can prevent major accidents
Rationale: The primary implication of the Heinrich Model is that by investigating and addressing
near misses and minor incidents, safety professionals can prevent major accidents from
occurring.
10. How does the Heinrich Model relate to the concept of "common cause hypothesis"?
A) It rejects the common cause hypothesis
B) It supports the common cause hypothesis by suggesting similar causes underlie both high
and low severity events
, C) It is unrelated to the common cause hypothesis
D) It replaces the common cause hypothesis
Answer: B) It supports the common cause hypothesis by suggesting similar causes underlie
both high and low severity events
Rationale: The common cause hypothesis, first posited by H.W. Heinrich, suggests that similar
causes underlie both high and low severity events. The Heinrich Model supports this hypothesis
by emphasizing the predictive validity of near misses.
11. Which of the following is a criticism of the Heinrich Model?
A) It overemphasizes system defects
B) It has been difficult to replicate the exact ratios in various settings
C) It ignores the role of worker behavior
D) It is too complex to implement
Answer: B) It has been difficult to replicate the exact ratios in various settings
Rationale: While the Heinrich Model has been influential, researchers have struggled to
replicate the exact ratios (1:29:300) across various settings and industries.
12. According to the Heinrich Model, what is the primary focus for improving safety
performance?
A) Punishing workers for unsafe acts
B) Improving the work system established by management
C) Reducing the number of workers
D) Increasing production quotas
Answer: B) Improving the work system established by management
Rationale: Heinrich's work emphasized that unsafe acts of workers are the principle causes of
occupational accidents, but improving the work system established by management is critical to
accident prevention.
13. How should safety professionals use the Heinrich Model in accident investigation?
A) Focus only on the most severe outcomes
B) Investigate near misses and minor injuries with the same rigor as major accidents
C) Ignore near misses as they cause no harm
D) Only investigate accidents that result in lost time
Answer: B) Investigate near misses and minor injuries with the same rigor as major accidents
Comprehensive Practice Exam – 300 Questions with
Answers, Choices, and Rationales
SECTION 1: THE HEINRICH MODEL AND ACCIDENT CAUSATION (Questions 1–20)
1. The Heinrich Model is best described as which of the following?
A) A financial model for safety budgeting
B) A model that explains the relationship between near misses, minor injuries, and major
accidents
C) A model for predicting equipment failure rates
D) A model for calculating insurance premiums
Answer: B) A model that explains the relationship between near misses, minor injuries, and
major accidents
Rationale: The Heinrich Model, also known as the safety triangle, posits that for every major
accident, there are 29 minor injuries and 300 near misses. This model emphasizes that
reducing near misses and minor incidents will lead to a reduction in major accidents.
2. Complete this sentence: "System defects are..."
A) Failures in individual employee performance
B) Weaknesses in the way the system is designed or operated
C) Errors caused by inadequate training only
D) Problems that cannot be corrected
Answer: B) Weaknesses in the way the system is designed or operated
Rationale: System defects refer to weaknesses in the way the system is designed or operated.
This concept is central to the Heinrich Model, which recognizes that accidents are often caused
by systemic issues rather than solely individual failures.
3. According to the Heinrich Model, what is the relationship between near misses and major
accidents?
A) Near misses are unrelated to major accidents
B) Near misses are precursors to major accidents
C) Major accidents cause near misses
D) Near misses only occur in high-risk industries
,Answer: B) Near misses are precursors to major accidents
Rationale: The Heinrich Model establishes that near misses are precursors to major accidents.
By addressing near misses, organizations can prevent more severe incidents from occurring.
4. Historically, accidents account for approximately what percentage of all U.S. Army casualties?
A) 10%
B) 30%
C) 50%
D) 70%
Answer: B) 30%
Rationale: Historically, accidents account for approximately 30% of all U.S. Army casualties.
This statistic underscores the importance of accident prevention within the Army Safety
Program.
5. The Heinrich Model suggests that reducing which type of incident will lead to a reduction in
major accidents?
A) Only major accidents
B) No-injury incidents and near misses
C) Equipment failures only
D) Only minor injuries
Answer: B) No-injury incidents and near misses
Rationale: Heinrich's theory suggests that a reduction in no-injury incidents (near misses) would
lead to a reduction in minor injury incidents and in major injury incidents.
6. Which of the following best describes the purpose of the Heinrich Model in safety
management?
A) To assign blame for accidents
B) To predict and prevent safety incidents
C) To calculate workers' compensation costs
D) To replace risk management processes
Answer: B) To predict and prevent safety incidents
Rationale: The Heinrich Model is used to analyze, predict, and prevent safety incidents by
focusing on the relationship between near misses, minor injuries, and major accidents.
,7. How does the Heinrich Model support the implementation of risk management?
A) By providing a framework for understanding accident causation
B) By eliminating the need for hazard identification
C) By replacing the need for safety training
D) By focusing only on major accidents
Answer: A) By providing a framework for understanding accident causation
Rationale: The Heinrich Model provides a framework for understanding how accidents are
caused, supporting risk management by emphasizing the importance of addressing
lower-severity incidents and near misses to prevent major accidents.
8. In the Heinrich Model, what is the ratio of major accidents to minor injuries to near misses?
A) 1:10:100
B) 1:29:300
C) 1:50:500
D) 1:100:1000
Answer: B) 1:29:300
Rationale: The Heinrich Model, often depicted as a triangle or pyramid, establishes the ratio of 1
major accident to 29 minor injuries to 300 near misses.
9. What is the primary implication of the Heinrich Model for safety professionals?
A) Only major accidents require investigation
B) Near misses should be ignored
C) Addressing near misses and minor incidents can prevent major accidents
D) Safety resources should be focused solely on catastrophic events
Answer: C) Addressing near misses and minor incidents can prevent major accidents
Rationale: The primary implication of the Heinrich Model is that by investigating and addressing
near misses and minor incidents, safety professionals can prevent major accidents from
occurring.
10. How does the Heinrich Model relate to the concept of "common cause hypothesis"?
A) It rejects the common cause hypothesis
B) It supports the common cause hypothesis by suggesting similar causes underlie both high
and low severity events
, C) It is unrelated to the common cause hypothesis
D) It replaces the common cause hypothesis
Answer: B) It supports the common cause hypothesis by suggesting similar causes underlie
both high and low severity events
Rationale: The common cause hypothesis, first posited by H.W. Heinrich, suggests that similar
causes underlie both high and low severity events. The Heinrich Model supports this hypothesis
by emphasizing the predictive validity of near misses.
11. Which of the following is a criticism of the Heinrich Model?
A) It overemphasizes system defects
B) It has been difficult to replicate the exact ratios in various settings
C) It ignores the role of worker behavior
D) It is too complex to implement
Answer: B) It has been difficult to replicate the exact ratios in various settings
Rationale: While the Heinrich Model has been influential, researchers have struggled to
replicate the exact ratios (1:29:300) across various settings and industries.
12. According to the Heinrich Model, what is the primary focus for improving safety
performance?
A) Punishing workers for unsafe acts
B) Improving the work system established by management
C) Reducing the number of workers
D) Increasing production quotas
Answer: B) Improving the work system established by management
Rationale: Heinrich's work emphasized that unsafe acts of workers are the principle causes of
occupational accidents, but improving the work system established by management is critical to
accident prevention.
13. How should safety professionals use the Heinrich Model in accident investigation?
A) Focus only on the most severe outcomes
B) Investigate near misses and minor injuries with the same rigor as major accidents
C) Ignore near misses as they cause no harm
D) Only investigate accidents that result in lost time
Answer: B) Investigate near misses and minor injuries with the same rigor as major accidents
