According to NFPA 72, smoke detectors shall not be installed if the ambient temperature is greater than which temperature, unless designed/listed for higher temperatures?

• A. >120 degrees F
• B. >80 degrees F
• C. >90 degrees F
• D. >100 degrees F

Answer: (D)

NFPA 72 requires that smoke detectors be installed only in environments whose ambient temperature is within the device’s listed operating range. For most standard smoke detectors, the upper limit is 100°F (38°C). If the area exceeds 100°F, you cannot use conventional smoke detectors unless they are specifically listed for higher temperatures. Using detectors rated for higher temps or choosing a different type (like heat detectors) ensures reliable operation and reduces the risk of false alarms or missed detections due to excessive heat. That’s why the correct threshold is 100°F.