Smoke Detector Failure Analysis


Smoke detector failure is a significant factor contributing to fire deaths and injuries in the United States. Here are some quick facts:

  • 2/3 of residential fire deaths occur in homes having no operational smoke detectors.
  • Smoke detector failure accounts for approximately 20% of these fire deaths, meaning smoke detectors were present but did not operate or sound.
  • More than 3/4 of smoke detector failures can be traced to missing/dead batteries or failure of hardwired power.
  • Approximately 10% of smoke detector failures are attributed to lack of maintenance, improper placement, or a defective unit.
  • Smoke detector failure can also be caused by painting over smoke detectors.

If it is suspected that smoke detector failure contributed to property loss, injuries, or fire deaths, the answers to several questions are usually sought:

  • Were smoke detectors present?
  • Were smoke detectors installed in the locations required by local/state ordinances, industry practice, and common sense?
  • Were smoke detectors installed in a location that could inhibit their performance, i.e. directly in the air stream produced by supply registers?
  • If smoke detectors or smoke alarms were present, did they activate and sound? Did witnesses hear any smoke alarms? Is there any evidence of preferential deposition of soot particles (acoustic agglomeration) on the openings hear the horn? If not, then smoke detector failure may have occurred.
  • How long after ignition would functional and properly installed smoke detectors have operated?
  • If smoke detector coverage was missing or inadequate or if smoke detector failure occurred, when would properly functioning and correctly installed smoke detectors have operated?
  • Would the smoke alarms have been audible to occupants?
  • How long after alarm did occupants have to escape before their means of egress became untenable due to fire?
    Would the time to alarm have been different if a photoelectric or ionization smoke detector was installed?
  • For hard wired detectors, does the electrical wiring show any signs of electrical anomalies that could have led to smoke detector failure?

For inquiries regarding smoke detector failure, please contact Chris Lautenberger.

Back to Reax Engineering forensic fire analysis services


            Fire modeling
            Fire testing
            Computational fluid dynamics
            Heat transfer analysis
            Failure analysis
            Fire investigation
            Wildland fires
            Vehicle fires
            Residential fires
            Smoke detector failure
            Ignition by hot particles
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Berkeley, CA 94704
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