Hydrogen Cyanide
in Service
Michael Magda
Livonia Fire & Rescue, Western
Wayne County HMRT
Presentation Content
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Toxic gases generated by fire
Hydrogen Cyanide in smoke
Health effects of HCN
ToxiRAE II HCN monitor
Toxic Gases
Generated by Fire
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
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?
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.
Clark County Fire Fighter
Fatality
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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
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
 >4000 firefighters injured by
smoke inhalation
 It is estimated up to 80% of all
fire fatalities are attributable to
smoke inhalation
Anatomy of Fire Smoke
 Toxic composition of smoke varies from fire to
fire
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Nature of the burning materials
Temperature
Oxygen level
Ventilation
 Conditions of high temperature and low oxygen enhance
degradation of synthetics quickening chemical release
Toxic Gases Generated by
Fire
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Carbon Monoxide
Carbon Dioxide
Hydrogen Cyanide
Hydrogen Chloride
Nitrous Gases
Phosgene
Hydrogen Sulfide
Sulfur Dioxide
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Acrolein
Ammonia
Formaldehyde
Glutaraldehyde
Acetaldehyde
Benzaldehyde
Benzene
Various PNAs
(polynuclear aromatic
hydrocarbons)
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
“ 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
Hydrogen Cyanide in
Smoke
Cyanide Producing
Materials
 Cyanide production in a fire
 Hydrogen cyanide is produced by
incomplete combustion of
nitrogen and carbon containing
substances (-C≡N)
 Natural Fibers (wool, silk, cotton,
paper)
 Synthetic polymers (nylon,
polyurethane)
 Synthetic rubber
 Melamine (resins for molding,
laminating, etc.)
HCN Releasing Polymers
 Synthetic polymers found extensively in
structures
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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
Sources of Cyanide
 Other small scale uses:
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Photography labs
Blue printing
Engraving computer chips
Cleaning or reconditioning
of jewelry
 Found at clandestine drug
lab
 manufacturing
phencyclidine (PCP)
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.
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
Health Effects of
HCN
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.
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
HCN or CO Poisoning
Acute S & S
 HCN
 CO
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Rapid breathing
Dizziness
Weakness
Nausea/vomiting
Eye irritation
Pink or red skin color
Rapid heart rate
Perspiration
Rapid breathing
Dizziness
Weakness
Nausea/vomiting
Eye irritation
Pink or red skin color
Rapid heart rate
Perspiration
Late Signs and Symptoms
 Later signs of exposure to moderate-high
concentrations include:
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Loss of consciousness
Respiratory arrest
Cardiac arrest
Coma
Seizures
Chemical Properties
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hydrocyanic acid
colorless gas or liquid
faint odor of bitter almonds
chemical warfare agent
 blood agent
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.
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
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 %
ToxiRAE II
HCN
ToxiRae II (HCN)
ToxiRAE II (HCN)
ToxiRAE II (HCN)
ToxiRAE II (HCN)
ToxiRAE II (HCN)
ToxiRAE II (HCN)
Questions!