33.1 Commentary

Causes of Unwanted Alarms:

● Cooking fumes, steam, tobacco smoke, dust, insects, aerosol spray, high air velocities, external smoke, cutting/welding, cosmetic smoke, incense, candles, electromagnetic interference, high humidity, water ingress, temperature fluctuations, accidental damage, maintenance/testing without precautions, water pressure surges.

Mitigation:

● Appropriate detection system choice and management.

● Use good quality, certified, and well-maintained equipment to reduce equipment false alarms.

Malicious False Alarms:

● Common in public spaces and educational institutions, often due to manual call points.

● Mitigate with careful placement and two-action devices.

False Alarms with Good Intent:

● Unlikely to be a major problem, but frequent occurrences can be addressed by controlling smoke-like processes, better informing staff, improving signage, using alarm covers, and applying variations if necessary.

33.2 Recommendations

Any person responsible for specification, design, commissioning or maintenance of fire detection and fire alarm systems should be conversant with the major causes of false alarms. Particular care should be taken to limit the potential for unwanted alarms and, in certain vulnerable premises, malicious false alarms.

33 Causes of false alarms