When testing the atmosphere in a confined space, what is the correct order for testing atmospheric hazards?
Correct Answer
C) Oxygen, flammable gases, toxic gases
The proper testing sequence is oxygen first (to ensure the atmosphere can support life), then flammable gases (to check for explosion hazards), and finally toxic gases. This sequence prioritizes the most immediate life-threatening hazards.
Why This Is the Correct Answer
Option B follows the correct OSHA-mandated testing sequence for confined spaces. Oxygen must be tested first because without adequate oxygen (19.5-23.5%), workers cannot safely enter or continue testing. Flammable gases are tested second because they pose immediate explosion risks that could be fatal. Toxic gases are tested last because while dangerous, they typically don't pose as immediate a threat as oxygen deficiency or explosion hazards.
Why the Other Options Are Wrong
Option A: Toxic gases, oxygen, flammable gases
Testing flammable gases first is incorrect because without knowing oxygen levels, the combustion risk cannot be properly assessed. Additionally, some gas detection equipment requires adequate oxygen to function accurately.
Option B: Oxygen, toxic gases, flammable gases
While this sequence correctly starts with oxygen, testing toxic gases before flammable gases reverses the priority of hazards. Explosion risks from flammable gases pose a more immediate threat than most toxic gas exposures.
Memory Technique
Use the acronym 'OFT' - Oxygen First, Then flammable gases, Then toxic gases. Think 'OFT-en people forget the correct order!'
Reference Hint
OSHA 29 CFR 1926.95 or Florida Building Code Chapter 33 - Safety Requirements for confined space entry procedures
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