Question 17Safety & Environmental - 1st Asst/Chief70% to pass
Before entering any space that has been sealed, its oxygen level should be tested. What level of oxygen in the space is equal to fresh air?
AI Explanation
The correct answer is C) 20.8%.
The oxygen level in fresh air is approximately 20.8%. This is the standard level of oxygen that should be present in a space before it is entered. If the oxygen level in a sealed space is below 20.8%, it indicates that the oxygen has been depleted and the space may not be safe to enter without proper ventilation and testing.
The other answer choices are incorrect because 10.0% is dangerously low, 15.8% is below the normal fresh air level, and 25.8% is abnormally high and could indicate the presence of enriched oxygen, which could also be hazardous.
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