When evaluating safety alarms, prioritize the decibel (dB) level, which should typically range between 120dB and 140dB to ensure audibility over long distances or in noisy environments. For personal safety alarms, look for dual-siren technology and integrated LED strobe lights to maximize visibility. For industrial or home safety alarms, verify the sensor range (PIR) and battery life expectancy, ideally seeking units with low-power consumption chips that offer at least 6-12 months of standby time.