HYDROGEN CYANIDE HCN

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HYDROGEN CYANIDE(HCN)

• The New Silent Killer

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IFSTA says

• Colorless gas with an almond odor
• IDLH atmosphere 50 PPM
• Chemical asphyxiate hampers respirations at the
  cellular and tissue level

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Where does HCN come from?

• Bi-product of combustion from ordinary
  combustibles (Cotton, silk, wool, nylon,
  polyurethane, melamine, acrylonitrile)
• Furniture, carpet, insulation, carpet,
  appliances, plastics, clothing, foam
• Nitrogen is the major factor

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More HCN Facts

• 35 times more toxic than CO
• Can enter the body through absorption,
  inhalation, and ingestion
• Targets the heart and brain
• Has a half life in blood of one hour
• Highly flammable

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How much can KILL?

• LC 50 Concentration
• 3404 PPM-1 minute
• 270 PPM- 6-8 minutes
• 181 PPM- 10 minutes
• 135 PPM- 30 minutes
• The most sensitive nose can detect .58 PPM
• 40 of population can not detect smell because of
  genetic or other factors

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Symptoms of exposure to smoke inhalation-associate
d cyanide poisoning

• Exposure to low concentrations
• Stupor, confusion, flushing, headache,
  perspiration, drowsiness, tachypnea,
• Exposure to higher concentration
• Prostration, tremors, arrythmia, respiratory
  depression, respiratory arrest, cardiovascular
  collapse

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The scary stuff

• If a firefighter absorbs 100mg/dl through the
  body, it would take 8 hours for the toxin to
  metabolize out of the system
• Changes in ECGs can be observed for up to 3
  weeks after a fire-related cyanide exposure
• WEAR YOR SCBA and CLEAN YOUR PPE

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Stories

• 2006-
• A firefighter is diagnosed with HCN poisoning
  following a structure fire
• Within 16 hours, 7 more firefighters from the
  same incident are diagnosed
• One of those suffered a heart attack- he was
  working at the pump panel during the incident

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Summary

• Cyanide exposure is an expected outcome of smoke
  inhalation in closed-space fires. Research has
  established that cyanide poisoning can be an
  important cause if incapacitation and death to
  victims as well as chronic health complications
  to firefighters.