An atmosphere that contains less than what percentage of oxygen is considered oxygen deficient?

An atmosphere that contains less than what percentage of oxygen is considered oxygen deficient?

• A. 19.5%
• B. 21%
• C. 18%
• D. 20.9%

Answer: (A)

An atmosphere is considered oxygen deficient when the oxygen content is less than 19.5 percent. Normal air contains about 20.9–21 percent oxygen, so values at or above that level aren’t deficient. The 19.5% cutoff is the standard used by OSHA to determine when precautions like monitoring and respiratory protection are needed.

An atmosphere is considered oxygen deficient when the oxygen content is less than 19.5 percent. Normal air contains about 20.9–21 percent oxygen, so values at or above that level aren’t deficient. The 19.5% cutoff is the standard used by OSHA to determine when precautions like monitoring and respiratory protection are needed.