Question 27Safety & Environmental - Assistant Engineer70% 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 oxygen level that is considered safe and normal for human habitation. Before entering any sealed space, the oxygen level should be tested to ensure it is at this normal fresh air level, indicating the space is not oxygen-deficient or oxygen-enriched, which could pose safety hazards.
The other answer choices are incorrect because 10.0% is dangerously low, 15.8% is below the normal range, and 25.8% would be considered oxygen-enriched, which also presents safety risks.
Related Questions
#25 If flammable vapors have penetrated a gas free space, which of the following actions would be the most hazardous to perform? #26 A tank has been sealed and unventilated for a long period of time. Which of the following statements is true? #28 The reading of a combustible gas indicator indicates the percentage of the _______________.#29 Combustible gas indicators incorporate the use of a/an _______________.#30 Before entering a fuel tank that has been cleaned, it should be checked with an oxygen indicator and a/an _______________.