🔍 Key Concepts

• Bypass valve purpose on a self-contained breathing apparatus (SCBA) • Difference between normal regulator air supply and emergency/backup air supply • Risks of using continuous air flow in hazardous atmospheres

💭 Think About

• Ask yourself: When would you need to supply air without depending on the regulator’s normal operation? • Which option describes a situation where equipment failure makes the normal demand system unreliable? • In which situations is it more important to keep the equipment functioning safely rather than just entering a hazardous space with it working normally?

✅ Before You Answer

• Verify which choice involves a regulator or demand system problem, not just the type of gas present. • Consider that the bypass valve usually provides a continuous emergency air flow, which will deplete the cylinder faster—would that be used all the time in hazardous atmospheres? • Eliminate options that only describe where you are going (environmental hazard) instead of a mechanical problem with the breathing apparatus.