NCCER Construction Site Safety Basics 3 — Questions and Answers
Question 1: What is the primary purpose of a Job Safety Analysis (JSA)?
- To calculate the cost of safety equipment for a project
- To break down a job into steps and identify potential hazards at each step (Correct answer)
- To determine which workers should be assigned to specific tasks
- To document completed safety training for regulatory compliance
Correct answer: To break down a job into steps and identify potential hazards at each step
A Job Safety Analysis systematically breaks down a task into individual steps and identifies the potential hazards associated with each step, along with controls to mitigate those hazards.
A JSA (also called Job Hazard Analysis or JHA) is a proactive safety tool that involves selecting a job, breaking it into sequential steps, identifying hazards at each step, and developing preventive measures. For example, a JSA for operating a circular saw would examine steps like inspecting the saw, positioning material, making the cut, and cleaning up — identifying hazards like blade contact, kickback, and electrical shock at each step. JSAs are living documents that should be reviewed and updated as conditions change.
Question 2: When is it necessary to use a full-body harness and lanyard on a construction site?
- Whenever working outdoors
- When working at heights of 6 feet or more above a lower level in general construction (Correct answer)
- Only when working on roofs steeper than 8/12 pitch
- When carrying tools weighing more than 25 pounds
Correct answer: When working at heights of 6 feet or more above a lower level in general construction
OSHA requires fall protection, including personal fall arrest systems like harnesses and lanyards, when construction workers are exposed to falls of 6 feet or more to a lower level.
The 6-foot threshold is the general industry standard for construction fall protection under OSHA 29 CFR 1926.501. At this height, employers must provide fall protection through guardrail systems, safety net systems, or personal fall arrest systems (harness and lanyard). Some specific activities have different thresholds — for example, steel erection requires fall protection at 15 feet, and scaffolding at 10 feet. The personal fall arrest system must be rigged so that a worker cannot free-fall more than 6 feet or contact any lower level.
Question 3: What should a worker do first upon discovering an unlabeled container of liquid at a construction site?
- Open the container and smell the contents to identify them
- Assume it is water and continue working
- Do not use the material and report it to the supervisor immediately (Correct answer)
- Pour the liquid into a labeled container
Correct answer: Do not use the material and report it to the supervisor immediately
Unlabeled containers must not be used. Workers should leave the container undisturbed and immediately notify their supervisor so the contents can be properly identified and handled.
OSHA's Hazard Communication Standard (HazCom) requires that all chemical containers be properly labeled with the product identifier, hazard warnings, and manufacturer information. An unlabeled container is a serious violation because the contents could be toxic, flammable, corrosive, or otherwise hazardous. Workers must never attempt to identify unknown chemicals by sight, smell, or taste. The correct response is to leave it alone and report it so a qualified person can identify the contents, properly label or dispose of the container, and address the labeling violation.
Question 4: Which signal should a worker give to a crane operator to indicate 'stop' using standard hand signals?
- Both arms extended outward with palms down, moving arms back and forth horizontally (Correct answer)
- One arm extended with palm up, making a circular motion
- One arm raised with a closed fist
- Both arms waving overhead in large circles
Correct answer: Both arms extended outward with palms down, moving arms back and forth horizontally
The standard hand signal for 'stop' is both arms extended outward from the body with palms down, moving the arms back and forth horizontally in a sweeping motion.
Standard crane hand signals are defined by OSHA and ASME B30.5 to ensure uniform communication between signal persons and crane operators. The 'stop' signal uses both arms extended horizontally with palms facing down, swept back and forth. 'Emergency stop' uses both arms extended with palms down, moving arms rapidly right and left. These signals must be learned by all personnel working around cranes. OSHA requires that the signal person be qualified and that the method of communication be established before operations begin.
Question 5: What is the maximum height at which a scaffold platform can be used without guardrails?
- 4 feet
- 6 feet
- 10 feet (Correct answer)
- Guardrails are always required on scaffolds
Correct answer: 10 feet
OSHA requires guardrails on scaffolds when the working platform is 10 feet or more above the next lower level, which is different from the 6-foot general construction fall protection threshold.
Scaffold fall protection has its own OSHA standard (29 CFR 1926.451). Guardrails are required when scaffold platforms are 10 feet or more above a lower level. This differs from the general construction 6-foot rule. The guardrail system must include a toprail at 38 to 45 inches above the platform, a midrail, and a toeboard. Cross-bracing can serve as a toprail or midrail if it meets the height requirements. Workers on scaffolds below 10 feet should still use good judgment and may voluntarily use fall protection.
Question 6: What must be included in a site-specific safety plan before construction work begins?
- Only the name of the safety officer and emergency phone numbers
- A comprehensive hazard assessment, emergency procedures, PPE requirements, and training documentation (Correct answer)
- A list of all workers and their home addresses
- The project budget and timeline only
Correct answer: A comprehensive hazard assessment, emergency procedures, PPE requirements, and training documentation
A site-specific safety plan must comprehensively address all anticipated hazards, required PPE, emergency procedures, safety training requirements, and specific controls for the work being performed.
A site-specific safety plan (also called a Health and Safety Plan or HASP) is a comprehensive document tailored to the specific hazards of a project. It typically includes: a hazard assessment for all anticipated work activities, required PPE for each task, emergency action procedures (evacuation routes, assembly points, emergency contacts), safety training requirements, specific procedures for high-hazard activities (confined space entry, hot work, excavations), environmental considerations, and documentation requirements. OSHA does not prescribe an exact format but requires that employers address all recognized hazards.
NCCER Construction Site Safety Basics 3
What is the primary purpose of a Job Safety Analysis (JSA)?