NCCER INDUSTRIAL PIPEFITTER
COMPREHENSIVE KNOWLEDGE PRACTICE EXAM
EDITION
National Center for Construction Education and Research (NCCER)
125 Questions | 9 Content Sections | 3-Hour Closed-Book Assessment
Minimum Passing Score: 75% (94/125) | Aligned with NCCER Pipefitter Curriculum 4th Edition
Multiple Choice (A–D) | Correct answers marked ✓
,SECTION 1: Safety – Ladders, Scaffolds, Motorized Equipment, Excavations
(Q1–Q16)
Q1. What is the MOST important hazardous condition in an excavation?
A. Accumulation of water at the bottom of the trench
B. Presence of underground utilities
C. The threat of a cave-in ✓
D. Exposure to hazardous gases
Correct Answer: C | Rationale: Cave-in is the most serious excavation hazard because it can bury
workers instantly with tons of soil, leaving no time to escape. OSHA identifies cave-in as the leading
cause of excavation fatalities. Water, utilities, and gases are serious but secondary hazards compared to
the immediate lethal threat of a cave-in.
Q2. OSHA requires that a competent person inspect an excavation at minimum:
A. Once per week
B. Before the start of each workshift and after any event that could affect stability
✓
C. Once per day at the end of the shift
D. Only after rainfall or other weather events
Correct Answer: B | Rationale: OSHA 29 CFR 1926.651 requires a competent person to inspect
excavations, adjacent areas, and protective systems before each workshift and after any event that
could affect stability (e.g., rain, frost, vibration). Inspection only after weather events or once daily is
insufficient for compliance.
Q3. The correct ratio for positioning a portable ladder against a wall (base distance to working
length) is:
A. 1:3 (one foot out for every three feet of height)
B. 1:4 (one foot out for every four feet of height) ✓
C. 1:5 (one foot out for every five feet of height)
D. 1:2 (one foot out for every two feet of height)
Correct Answer: B | Rationale: The 4:1 rule (or 75° angle) is the standard for portable ladder
positioning: the base is placed one foot away from the wall for every four feet of vertical height. This
provides optimal stability. A 1:3 ratio is too steep; 1:5 is too shallow; 1:2 creates excessive outward lean,
all increasing fall risk.
Q4. A pipefitter discovers a damaged hand tool with a cracked handle on the job site. The
CORRECT immediate action is to:
A. Use the tool carefully until end of shift, then report it
B. Wrap the crack with electrical tape and continue using it
, C. Take the tool out of service immediately and tag it for repair or replacement ✓
D. Notify the supervisor and continue using the tool with caution
Correct Answer: C | Rationale: Damaged or broken tools must be taken out of service immediately
— they must not be used under any circumstances. NCCER and OSHA standards require tagging
defective tools to prevent use. Temporary repairs like tape do not restore structural integrity and create
additional hazards.
Q5. Before performing work on a scaffold, which of the following must be present?
A. A ladder positioned at each end of the scaffold
B. A competent person's daily inspection and guardrails on all open sides and ends
above 10 feet ✓
C. Written approval from the project engineer only
D. A safety harness for every worker regardless of height
Correct Answer: B | Rationale: OSHA 29 CFR 1926.451 requires scaffolds to be inspected by a
competent person before each work shift, and guardrails must be installed on all open sides and ends of
scaffold platforms more than 10 feet above the ground or lower level. Written engineering approval
alone is insufficient without the competent person inspection.
Q6. When working near an excavation, spoil piles must be kept at least _____ from the edge of the
trench.
A. 1 foot
B. 2 feet ✓
C. 3 feet
D. 5 feet
Correct Answer: B | Rationale: OSHA requires excavated material (spoil piles) to be kept at least 2
feet from the edge of the excavation. Spoil too close to the edge increases surcharge load and the risk of
cave-in, and can slide back into the trench, burying workers.
Q7. Which type of soil is classified as the MOST stable and requires minimal sloping or shoring?
A. Type C — granular soil with no cohesion
B. Type B — previously disturbed soil
C. Type A — cohesive soil such as clay with unconfined compressive strength of 1.5
tsf or greater ✓
D. Type D — saturated sandy soil
Correct Answer: C | Rationale: OSHA classifies soil into three categories: Type A (most stable —
cohesive clay, unconfined compressive strength ≥1.5 tsf), Type B (intermediate), and Type C (least stable
— granular, submerged, or fissured). Type D is not an OSHA classification. Type A requires the least
slope (¾:1 H:V) while Type C requires 1½:1.
Q8. A scaffold must be capable of supporting its own weight plus at least _____ times the
intended load.
, A. 2 times
B. 3 times
C. 4 times ✓
D. 5 times
Correct Answer: C | Rationale: OSHA 29 CFR 1926.451(a)(1) requires scaffolds to be designed and
constructed to support their own weight and at least four times the maximum intended load. This safety
factor ensures structural redundancy against overload, dynamic loading, and material variability.
Q9. What Personal Protective Equipment (PPE) is REQUIRED when operating an oxygen-
acetylene cutting torch?
A. Standard safety glasses and leather work gloves
B. Cutting goggles with the appropriate shade lens, leather gloves, and flame-
resistant clothing ✓
C. A full-face shield, rubber gloves, and cotton clothing
D. Safety glasses with side shields and synthetic gloves
Correct Answer: B | Rationale: Oxy-fuel cutting requires cutting goggles (not standard safety
glasses) with shade 3–6 lenses for eye protection from infrared and ultraviolet radiation, leather gloves
to protect from sparks and heat, and flame-resistant clothing. Rubber gloves and synthetic clothing are
fire hazards. A full face shield alone without proper shade lenses is insufficient.
Q10. An employee is working in a trench 6 feet deep in Type C soil. OSHA requires the trench
walls to be sloped at a maximum angle of:
A. 53° from horizontal (¾:1 H:V)
B. 45° from horizontal (1:1 H:V)
C. 34° from horizontal (1½:1 H:V) ✓
D. 90° (vertical) with timber shoring
Correct Answer: C | Rationale: Type C soil (least stable) requires a maximum slope of 1½:1 H:V (34°
from horizontal). Type B requires 1:1 (45°) and Type A requires ¾:1 (53°). Vertical walls in any
unshored excavation deeper than 5 feet (except in stable rock) are prohibited for worker entry under
OSHA standards.
Q11. Which of the following is the PRIMARY purpose of a safety harness and lanyard when
working at heights above 6 feet on a construction site?
A. To support the worker's weight during normal operations
B. To arrest a fall and limit the worker's free-fall distance to 6 feet or less ✓
C. To prevent the worker from reaching the edge of the work surface
D. To attach tools to the worker's body to prevent dropped objects
Correct Answer: B | Rationale: A personal fall arrest system (PFAS) — harness and lanyard —
arrests a fall and limits free-fall to 6 feet or less (per OSHA 29 CFR 1926.502). The system must
decelerate and stop the fall without subjecting the worker to more than 1,800 lbs of arresting force. It is
not a positioning device or tool tether.
COMPREHENSIVE KNOWLEDGE PRACTICE EXAM
EDITION
National Center for Construction Education and Research (NCCER)
125 Questions | 9 Content Sections | 3-Hour Closed-Book Assessment
Minimum Passing Score: 75% (94/125) | Aligned with NCCER Pipefitter Curriculum 4th Edition
Multiple Choice (A–D) | Correct answers marked ✓
,SECTION 1: Safety – Ladders, Scaffolds, Motorized Equipment, Excavations
(Q1–Q16)
Q1. What is the MOST important hazardous condition in an excavation?
A. Accumulation of water at the bottom of the trench
B. Presence of underground utilities
C. The threat of a cave-in ✓
D. Exposure to hazardous gases
Correct Answer: C | Rationale: Cave-in is the most serious excavation hazard because it can bury
workers instantly with tons of soil, leaving no time to escape. OSHA identifies cave-in as the leading
cause of excavation fatalities. Water, utilities, and gases are serious but secondary hazards compared to
the immediate lethal threat of a cave-in.
Q2. OSHA requires that a competent person inspect an excavation at minimum:
A. Once per week
B. Before the start of each workshift and after any event that could affect stability
✓
C. Once per day at the end of the shift
D. Only after rainfall or other weather events
Correct Answer: B | Rationale: OSHA 29 CFR 1926.651 requires a competent person to inspect
excavations, adjacent areas, and protective systems before each workshift and after any event that
could affect stability (e.g., rain, frost, vibration). Inspection only after weather events or once daily is
insufficient for compliance.
Q3. The correct ratio for positioning a portable ladder against a wall (base distance to working
length) is:
A. 1:3 (one foot out for every three feet of height)
B. 1:4 (one foot out for every four feet of height) ✓
C. 1:5 (one foot out for every five feet of height)
D. 1:2 (one foot out for every two feet of height)
Correct Answer: B | Rationale: The 4:1 rule (or 75° angle) is the standard for portable ladder
positioning: the base is placed one foot away from the wall for every four feet of vertical height. This
provides optimal stability. A 1:3 ratio is too steep; 1:5 is too shallow; 1:2 creates excessive outward lean,
all increasing fall risk.
Q4. A pipefitter discovers a damaged hand tool with a cracked handle on the job site. The
CORRECT immediate action is to:
A. Use the tool carefully until end of shift, then report it
B. Wrap the crack with electrical tape and continue using it
, C. Take the tool out of service immediately and tag it for repair or replacement ✓
D. Notify the supervisor and continue using the tool with caution
Correct Answer: C | Rationale: Damaged or broken tools must be taken out of service immediately
— they must not be used under any circumstances. NCCER and OSHA standards require tagging
defective tools to prevent use. Temporary repairs like tape do not restore structural integrity and create
additional hazards.
Q5. Before performing work on a scaffold, which of the following must be present?
A. A ladder positioned at each end of the scaffold
B. A competent person's daily inspection and guardrails on all open sides and ends
above 10 feet ✓
C. Written approval from the project engineer only
D. A safety harness for every worker regardless of height
Correct Answer: B | Rationale: OSHA 29 CFR 1926.451 requires scaffolds to be inspected by a
competent person before each work shift, and guardrails must be installed on all open sides and ends of
scaffold platforms more than 10 feet above the ground or lower level. Written engineering approval
alone is insufficient without the competent person inspection.
Q6. When working near an excavation, spoil piles must be kept at least _____ from the edge of the
trench.
A. 1 foot
B. 2 feet ✓
C. 3 feet
D. 5 feet
Correct Answer: B | Rationale: OSHA requires excavated material (spoil piles) to be kept at least 2
feet from the edge of the excavation. Spoil too close to the edge increases surcharge load and the risk of
cave-in, and can slide back into the trench, burying workers.
Q7. Which type of soil is classified as the MOST stable and requires minimal sloping or shoring?
A. Type C — granular soil with no cohesion
B. Type B — previously disturbed soil
C. Type A — cohesive soil such as clay with unconfined compressive strength of 1.5
tsf or greater ✓
D. Type D — saturated sandy soil
Correct Answer: C | Rationale: OSHA classifies soil into three categories: Type A (most stable —
cohesive clay, unconfined compressive strength ≥1.5 tsf), Type B (intermediate), and Type C (least stable
— granular, submerged, or fissured). Type D is not an OSHA classification. Type A requires the least
slope (¾:1 H:V) while Type C requires 1½:1.
Q8. A scaffold must be capable of supporting its own weight plus at least _____ times the
intended load.
, A. 2 times
B. 3 times
C. 4 times ✓
D. 5 times
Correct Answer: C | Rationale: OSHA 29 CFR 1926.451(a)(1) requires scaffolds to be designed and
constructed to support their own weight and at least four times the maximum intended load. This safety
factor ensures structural redundancy against overload, dynamic loading, and material variability.
Q9. What Personal Protective Equipment (PPE) is REQUIRED when operating an oxygen-
acetylene cutting torch?
A. Standard safety glasses and leather work gloves
B. Cutting goggles with the appropriate shade lens, leather gloves, and flame-
resistant clothing ✓
C. A full-face shield, rubber gloves, and cotton clothing
D. Safety glasses with side shields and synthetic gloves
Correct Answer: B | Rationale: Oxy-fuel cutting requires cutting goggles (not standard safety
glasses) with shade 3–6 lenses for eye protection from infrared and ultraviolet radiation, leather gloves
to protect from sparks and heat, and flame-resistant clothing. Rubber gloves and synthetic clothing are
fire hazards. A full face shield alone without proper shade lenses is insufficient.
Q10. An employee is working in a trench 6 feet deep in Type C soil. OSHA requires the trench
walls to be sloped at a maximum angle of:
A. 53° from horizontal (¾:1 H:V)
B. 45° from horizontal (1:1 H:V)
C. 34° from horizontal (1½:1 H:V) ✓
D. 90° (vertical) with timber shoring
Correct Answer: C | Rationale: Type C soil (least stable) requires a maximum slope of 1½:1 H:V (34°
from horizontal). Type B requires 1:1 (45°) and Type A requires ¾:1 (53°). Vertical walls in any
unshored excavation deeper than 5 feet (except in stable rock) are prohibited for worker entry under
OSHA standards.
Q11. Which of the following is the PRIMARY purpose of a safety harness and lanyard when
working at heights above 6 feet on a construction site?
A. To support the worker's weight during normal operations
B. To arrest a fall and limit the worker's free-fall distance to 6 feet or less ✓
C. To prevent the worker from reaching the edge of the work surface
D. To attach tools to the worker's body to prevent dropped objects
Correct Answer: B | Rationale: A personal fall arrest system (PFAS) — harness and lanyard —
arrests a fall and limits free-fall to 6 feet or less (per OSHA 29 CFR 1926.502). The system must
decelerate and stop the fall without subjecting the worker to more than 1,800 lbs of arresting force. It is
not a positioning device or tool tether.
