When must a competent person inspect an excavation for hazardous atmospheres?
Correct Answer
B) When the excavation exceeds 4 feet in depth
OSHA requires atmospheric testing by a competent person when excavations are 4 feet or deeper, especially where oxygen deficiency or hazardous atmospheres could reasonably be expected.
Why This Is the Correct Answer
CORRECT_ANSWER - OSHA 29 CFR 1926.651(g)(1)(i) specifically requires that excavations 4 feet or deeper must be tested by a competent person for hazardous atmospheric conditions before workers enter. This depth threshold is critical because deeper excavations are more likely to accumulate dangerous gases, experience oxygen deficiency, or contain other atmospheric hazards. The 4-foot rule applies regardless of soil type, location, or presence of utilities, making it a universal safety standard for excavation work.
Why the Other Options Are Wrong
Option C: Only when gas lines are present
This is insufficient and dangerous. While weather events like rain can change atmospheric conditions and may trigger additional testing, limiting inspections only to post-weather events ignores the fundamental requirement for testing all excavations 4 feet or deeper.
Option D: Only after rain or other weather events
This is excessive and not what OSHA requires. Daily testing at each shift start would be impractical and is not mandated by regulations. Testing is required when excavations reach 4 feet in depth and when conditions change significantly.
Memory Technique
Think 'FOUR FEET = FRESH AIR CHECK' - once you dig 4 feet down, you must check the air before anyone goes down.
Reference Hint
OSHA 29 CFR 1926.651 - Specific Excavation Requirements, subsection (g) Hazardous Atmospheres
More Project Mgmt Questions
What is the minimum R-value required for wall insulation in Florida Climate Zone 2?
A subcontractor brings a new chemical product to your jobsite. Under the Globally Harmonized System (GHS), what information must be immediately available to workers?
A construction site has a trench that is 8 feet deep in Type B soil. What is the maximum allowable slope ratio for the trench walls without protective systems?
What is the maximum recommended spacing between drywall screws when attaching to wood studs?
Your crew discovers suspected asbestos-containing materials during a renovation project. What is the first action you should take?
A scaffold platform is 12 feet long and 5 feet wide. If the maximum load capacity is 25 pounds per square foot, what is the total weight capacity of this platform?
Which CSI MasterFormat Division would contain specifications for fire-stopping and firesafing materials?
In tilt-up concrete construction, what is the primary advantage of this method over conventional cast-in-place construction?
Which OSHA standard specifically addresses construction industry safety and health regulations?
A structural drawing shows a beam labeled 'W12x26'. What does the '26' represent?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass