Acceptable low oxygen as defined by OSHA exists between ___% -___%.

Acceptable low oxygen as defined by OSHA exists between ___% -___%.

• A. 19.5% to 20.9%
• B. 18% to 23%
• C. 20% to 22%
• D. 15% to 18%

Answer: (A)

In OSHA terms, the line between breathable air and oxygen-deficient air is around 19.5%. Normal breathing air sits near 20.9% O2, so the range that's considered still “acceptable low” is from 19.5% up to about 20.9%. This captures the lower bound of deficiency and the upper bound of normal ambient oxygen. Therefore, the best fit is 19.5% to 20.9%. The other ranges either include clearly deficient levels or stay entirely within normal air, which isn’t the “low” category.

In OSHA terms, the line between breathable air and oxygen-deficient air is around 19.5%. Normal breathing air sits near 20.9% O2, so the range that's considered still “acceptable low” is from 19.5% up to about 20.9%. This captures the lower bound of deficiency and the upper bound of normal ambient oxygen. Therefore, the best fit is 19.5% to 20.9%. The other ranges either include clearly deficient levels or stay entirely within normal air, which isn’t the “low” category.