Hydrogen Cyanide in Service

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Hydrogen Cyanide in Service

• Michael Magda
• Livonia Fire Rescue, Western Wayne County HMRT

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Presentation Content

• Toxic gases generated by fire
• Hydrogen Cyanide in smoke
• Health effects of HCN
• ToxiRAE II HCN monitor

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Toxic Gases Generated by Fire
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Clark County Fire Fighter Fatality

• Crews operating at the scene of a commercial dice
  factory fire
• Heavy smoke and fire conditions
• All crews are instructed to utilize standard PPE
• SCBA are used by all responders

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Clark County Fire Fighter Fatality

• What are some of the hazards present?
• As a Incident Commander, what types of injuries
  or conditions may you expect?

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Clark County Fire Fighter Fatality

• All crews are ordered out of the structure.
• As crews leave the factory, they remove their
  SCBA masks.
• A Fire Captain removes his mask as he walks out
  of the smoke. He collapses outside the structure.
• He is in cardiac arrest.

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Clark County Fire Fighter Fatality

• The Captain did not survive his injuries
• Coroner ruled this fatality due to cyanide
  toxicity.
• Clark County Fire Department
• Captain Frank E. Testa, April 11, 1970

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2005 Fire Statistics

• In 2005, there were 1,602,000 fires reported in
  U.S.
• 511,000 structure fires
• 3,105 civilian deaths
• 15,325 civilian injuries
• 9.2 billion in property damage
• 87 firefighter deaths in all types of fires
• gt4000 firefighters injured by smoke inhalation
• It is estimated up to 80 of all fire fatalities
  are attributable to smoke inhalation

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Anatomy of Fire Smoke

• Toxic composition of smoke varies from fire to
  fire
• Nature of the burning materials
• Temperature
• Oxygen level
• Ventilation
• Conditions of high temperature and low oxygen
  enhance degradation of synthetics quickening
  chemical release

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Toxic Gases Generated by Fire

• Carbon Monoxide
• Carbon Dioxide
• Hydrogen Cyanide
• Hydrogen Chloride
• Nitrous Gases
• Phosgene
• Hydrogen Sulfide
• Sulfur Dioxide

• Acrolein
• Ammonia
• Formaldehyde
• Glutaraldehyde
• Acetaldehyde
• Benzaldehyde
• Benzene
• Various PNAs (polynuclear aromatic hydrocarbons)

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Cyanide Toxicity in Smoke

• Historically, carbon monoxide asphyxiation has
  been considered the primary cause of deaths of
  those overcome by smoke
• Focus of gas monitoring
• There is mounting evidence that hydrogen cyanide
  is directly responsible for many more deaths than
  previously assumed
• Cumulative effect with CO worse than either
  individually

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• Cyanide toxicity from smoke inhalation in a
  structural or enclosed space fire is the most
  likely cause of cyanide toxicity that EMS fire
  professionals will encounter
• JEMS Communications Summer 2004

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Hydrogen Cyanide in Smoke
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Cyanide Producing Materials

• Cyanide production in a fire
• Hydrogen cyanide is produced by incomplete
  combustion of nitrogen and carbon containing
  substances (-CN)
• Natural Fibers (wool, silk, cotton, paper)
• Synthetic polymers (nylon, polyurethane)
• Synthetic rubber
• Melamine (resins for molding, laminating, etc.)

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HCN Releasing Polymers

• Synthetic polymers found extensively in
  structures
• Insulation
• Cushioning
• Carpets
• Bedding (mattresses and pillows)
• Building materials
• Materials can burn up to 2-3 times hotter and
  faster than natural materials
• Quicker flashovers increase speed of HCN release

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Sources of Cyanide

• Other small scale uses
• Photography labs
• Blue printing
• Engraving computer chips
• Cleaning or reconditioning of jewelry
• Found at clandestine drug lab
• manufacturing phencyclidine (PCP)

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Key Cyanide Studies

• Two independent studies performed on HCN toxicity
• Paris France (1988-89)
• 109 fire victims( 66 survivors and 43 fatalities)
  144 controlled individuals (drug intoxication and
  CO poisoning)
• Dallas County Texas
• 144 smoke inhalation patients at University of
  Texas Health Science Center Emergency Department
  43 deceased individuals at Dallas County medical
  examiners office.

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Key Cyanide Studies

• Final Conclusion
• Cyanide and carbon monoxide were both important
  determinants of smoke inhalation - associated
  morbidity and mortality.
• Cyanide concentrations were directly related to
  the probability of death.
• Cyanide may have dominated over CO as a cause of
  death in some fire victims.
• Cyanide and CO may have potentiated the toxic
  effects of one another

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Health Effects of HCN
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Health Effects of HCN

• Small amounts are present in the environment and
  in humans.
• Normal levels of whole blood are between 0 to 20
  micrograms per deciliter (ug/dl).
• Cyanide levels as low as 50 ug/dl in the blood
  have proven to be toxic, and blood cyanide levels
  of 250 300 ug/dl fatal.
• Symptoms of cyanide poisoning mimic the signs and
  symptoms of a myocardial infarction. 

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Early Signs and Symptoms

• Early signs and symptoms of exposure to low
  concentrations of cyanide include
• Rapid breathing
• Dizziness
• Weakness
• Nausea/vomiting
• Eye irritation
• Pink or red skin color
• Rapid heart rate
• Perspiration

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HCN or CO Poisoning Acute S S

• HCN
• Rapid breathing
• Dizziness
• Weakness
• Nausea/vomiting
• Eye irritation
• Pink or red skin color
• Rapid heart rate
• Perspiration

• CO
• Rapid breathing
• Dizziness
• Weakness
• Nausea/vomiting
• Eye irritation
• Pink or red skin color
• Rapid heart rate
• Perspiration

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Late Signs and Symptoms

• Later signs of exposure to moderate-high
  concentrations include
• Loss of consciousness
• Respiratory arrest
• Cardiac arrest
• Coma
• Seizures

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Chemical Properties

• hydrocyanic acid
• colorless gas or liquid
• faint odor of bitter almonds
• chemical warfare agent
• blood agent

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Chemical Properties

• Categorized as a blood agent.
• Enters the blood stream and prevents
  intracellular oxygen utilization
• chemical asphyxiation even in the presence of
  adequate oxygen in the atmosphere.
• (DOT) classifies
• 6.1 poison.
• NFPA
• Health 4, Flammability 4 and Reactivity 2.

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NIOSH Facts

• Exposure Limits
• NIOSH REL ST 4.7 ppm (5 mg/m3) skin OSHA PEL
  TWA 10 ppm (11 mg/m3) skin
• IDLH
• 50ppm
• Target Organs
• central nervous system, cardiovascular system,
  thyroid, blood
• Exposure Routes
• inhalation, skin absorption, ingestion, skin
  and/or eye contact

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NIOSH Facts

• Time Weighted Average
• Carbon Monoxide - 35 ppm.....Hydrogen Cyanide -
  4.7 ppm
• IDLH
• Carbon Monoxide - 1200 ppm.....Hydrogen Cyanide -
  50 ppm
• Lower Explosive Limit
• Carbon Monoxide - 12.5.....Hydrogen Cyanide -
  5.6
• Upper Explosive Limit
• Carbon Monoxide - 74 .....Hydrogen Cyanide - 40
  

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ToxiRAE II HCN
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ToxiRae II (HCN)
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ToxiRAE II (HCN)
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ToxiRAE II (HCN)
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ToxiRAE II (HCN)
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ToxiRAE II (HCN)
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ToxiRAE II (HCN)

• Questions!