Mixed Deck — All STSC Topics Flashcards

A contractor decides to use a timber shoring system in a trench. Who must design the shoring system?

Answer: A tabulated data system approved by a registered professional engineer, or a custom design by a registered PE

Under OSHA Appendix C to Subpart P, timber shoring must either follow tabulated data (pre-engineered tables by a registered PE) or be custom-designed by a registered professional engineer for the specific project conditions.

A covered floor opening is discovered on a job site without a hole cover. What immediate action should a supervisor take?

Answer: Guard the opening immediately and install a proper cover or barricade

OSHA 1926.502(i) requires floor holes to be guarded by a railing and cover immediately — the supervisor must act at once to prevent falls.

What is the primary purpose of a confined space entry permit?

Answer: To verify that pre-entry precautions have been completed

The entry permit, as required by OSHA 1926.1206, serves as a safety checklist and a formal authorization document. Its purpose is to ensure that all hazards have been identified, evaluated, and controlled through measures like isolation, ventilation, and atmospheric testing before any worker enters the space.

Which of the following is the correct hierarchy of controls for preventing accidents at construction sites?

Answer: Elimination → Substitution → Engineering controls → Administrative controls → PPE

The hierarchy of controls ranks hazard control methods from most to least effective: Elimination, Substitution, Engineering controls, Administrative controls, and PPE (last resort).

The term 'near miss' in construction safety refers to:

Answer: A close call where no injury or damage occurred but could have

A near miss is an unplanned event that did not result in injury or damage but had the potential to do so under slightly different circumstances.

What is the correct method for carrying sharp-edged or pointed tools on a construction site?

Answer: With the point or blade covered and directed away from the body

Sharp tools must be carried with the cutting edge or point protected and directed away from the body to prevent accidental lacerations.

Which gas is often called a 'simple asphyxiant' and is particularly dangerous in confined spaces because it is odorless and colorless?

Answer: Nitrogen

Nitrogen is a simple asphyxiant that displaces oxygen without any warning odor or color, making it extremely dangerous in confined spaces.

What is the employer's responsibility regarding PPE under OSHA 29 CFR 1926.28?

Answer: Employers must provide and ensure use of appropriate PPE at no cost to employees

OSHA 1926.28 and the PPE payment rule (29 CFR 1910.132(h)) require employers to provide PPE at no cost to employees, except for safety-toed footwear, prescription safety glasses, and logging boots (which employers may require workers to provide).

Under OSHA 1926.502, what is the minimum distance a warning line must be set back from an unprotected edge on a low-slope roof?

Answer: 6 feet

Warning lines must be erected at least 6 feet from the roof edge under OSHA 1926.502(f)(2)(i) when used with other protective measures.

A construction supervisor who micromanages every worker task is most likely to create which safety risk?

Answer: Worker dependence that reduces independent hazard recognition and reporting

Micromanagement suppresses worker initiative, reducing their ability to identify and respond to hazards independently when the supervisor is absent.

A crew is cutting fiber cement siding. Under OSHA's Table 1 of the silica standard (1926.1153), which control is REQUIRED to limit silica exposure during this task?

Answer: Wet cutting methods or use of a saw with an integrated HEPA-filtered vacuum

OSHA's Table 1 specifies task-specific engineering controls; for cutting fiber cement, wet methods or a vacuum with a HEPA filter are required. An employer who fully complies with Table 1 is deemed to have met the exposure assessment requirements — no separate air monitoring is needed.

Which leadership style is generally MOST effective when training a new, inexperienced construction worker on safety procedures?

Answer: Directing — providing clear, specific instructions and close supervision

New workers lack the knowledge base to self-direct, so a directing style with close supervision is most appropriate for safety-critical tasks.

What is the primary purpose of OSHA's Process Safety Management (PSM) standard in the context of construction work?

Answer: It may apply to construction contractors working in or around facilities that process highly hazardous chemicals above threshold quantities

PSM may apply to construction contractors performing work within facilities that handle highly hazardous chemicals above OSHA threshold quantities, requiring coordination between the host employer and contractors.

When rigging a load with a basket hitch using a wire rope sling, what factor most significantly affects the sling's working load limit?

Answer: The horizontal angle of the sling legs relative to the load

As the sling angle decreases below 90°, the tension on each sling leg increases dramatically, reducing the effective working load limit.

A construction crew is working on a bridge over a river. Which fall protection system is most appropriate when workers must move frequently along the structure?

Answer: Self-retracting lifeline on a horizontal lifeline

A self-retracting lifeline on a horizontal lifeline allows freedom of movement along the structure while maintaining continuous fall protection.

Hot work permits are required for operations that produce sparks or flame because:

Answer: They ensure fire hazards are identified, combustibles removed, and fire watches are established before work begins

Hot work permits create a systematic process to evaluate and control ignition hazards before welding, cutting, or grinding begins.

Which ANSI/ISEA standard governs the performance requirements for high-visibility safety apparel used on construction sites?

Answer: ANSI/ISEA 107

ANSI/ISEA 107 establishes performance requirements for high-visibility safety apparel and headwear.

Which class of portable fire extinguisher is appropriate for a fire involving energized electrical power tools?

Answer: Class C

Class C extinguishers are rated for energized electrical fires because they use non-conductive agents that will not conduct electricity back to the operator.

Under OSHA 29 CFR 1926.95, who is responsible for ensuring that required PPE is provided, used, and maintained?

Answer: The employer

OSHA 29 CFR 1926.95 places the responsibility for providing, enforcing, and maintaining PPE squarely on the employer.

Which type of fire extinguisher is PROHIBITED for use on electrical fires (Class C) due to the risk of electrical conductivity?

Answer: Water (stored pressure)

Water is electrically conductive and can cause electrocution if used on energized electrical equipment fires.