Final answer:
The first priority when an alarm is activated on a vent is to ensure safety by evacuating the area and alerting others to the alarm.
Step-by-step explanation:
The first priority when an alarm is activated on a vent is to ensure the safety of individuals. This includes evacuating the area immediately and alerting others to the alarm. Additionally, it is important to contact emergency services such as fire department or appropriate authorities to report the alarm and any potential hazards.
Keywords: safety, evacuate, alarm, emergency services