Which statement about atmospheric pressure at sea level is accurate?

• A. It is exactly 15 psi
• B. It is approximately 12 psi
• C. It is approximately 14.7 psi
• D. It is approximately 20 psi

Answer: (C)

Sea-level atmospheric pressure is a defined standard used as a reference for many calculations. It equals about 101.3 kilopascals, and when you convert that to the common unit psi, you get roughly 14.7 psi. That’s why saying it is approximately 14.7 psi is the best answer—it matches the standard reference value used in hazmat work and pressure calculations. Real-world pressure can vary a bit with weather, but 14.7 psi is the accepted baseline. Values like 15 psi are only a rough approximation and not the standard reference, while 12 psi and 20 psi are noticeably outside the typical range for sea-level pressure.