Emergency Medical Technician (EMT) Intermediate Practice Exam 2026 – 400 Free Practice Questions to Pass the Exam

A portable oxygen cylinder should be taken out of service and refilled when the pressure inside it is at 500 psi or below, as this level indicates that there is insufficient oxygen remaining for safe patient care and transport. Oxygen is critical in emergency medical situations, and maintaining an adequate supply is essential for effective treatment of patients, particularly in respiratory distress or other conditions requiring supplemental oxygen.

When the pressure in the cylinder drops to 500 psi, it is generally considered to be a threshold indicating that the cylinder is nearing depletion and should be refilled to ensure that healthcare providers can deliver the necessary support without interruptions. Lower pressures indicate a higher risk of running out of oxygen during a critical moment, thus emphasizing the importance of adhering to this standard to ensure optimal patient outcomes. Refilling the cylinder before reaching this pressure is a best practice to prevent any potential service interruptions in emergency scenarios.