Which statement regarding the two SCBA types in fire service use is correct?

• A. In an Open-circuit SCBA, inhaled air is vented to the outside atmosphere
• B. In a Closed-circuit SCBA, inhaled air stays in the system for filtering, cleaning and circulation
• C. The Closed-circuit type is commonly used for structural firefighting
• D. SCBAs for fire service use are designed and built in accordance with NFPA Standards

Answer: (D)

SCBA safety comes from meeting established standards that govern design, performance, and maintenance. In fire service use, SCBAs are designed and built to NFPA standards. Those standards specify how the equipment should perform, how it’s tested, how alarms and regulators work, and how it’s labeled and serviced. This shared framework ensures that open-circuit and closed-circuit designs deliver reliable breathing protection under firefighting conditions and that gear from different manufacturers meets the same safety criteria. Describing how each type operates—venting inhaled air to the outside or recirculating and filtering air—is useful for understanding function, but the statement about NFPA standard compliance is the strongest answer because it underpins safety, interoperability, and consistency across all fire-service SCBAs.