Hydrogen Cyanide
And the effects it has on the human
body
Purpose
To understand the dangers of Hydrogen
Cyanide and the possibilities of exposure
for the personnel of the Helena Fire Dept.
Objectives
• Understand the unseen risks that are
present in smoke.
• Learn about the more prevalent
byproducts of combustion involved in a
structure fire - specifically hydrogen
cyanide.
• Understand the effects of fire gases on the
human body.
Objectives cont..
• Become informed of possible monitoring
and treatment techniques that have been
developed or tested.
• Learn about what to do in the event of a
possible exposure to a toxic byproduct.
Between 1997 and 2006, there were 30,564
fire deaths and 151,575 injuries
attributable to fire. Only 1% of those
represent burn injuries. The leading
cause of fire death: SMOKE Inhalation.
PPE ???? The SCBA is on, but no mask or hood!!!!
Smoke defined
Smoke: the gaseous product of burning
materials especially of organic origin made
visible by the presence of small particles
of carbon.
- Webster’s Dictionary
Anatomy of Fire Smoke
The make-up of smoke can differ from fire
to fire due to a number of different things
– Although smoke from the majority of structure
fires is mainly composed of particulate
matters and heated gases.
– Up to 80% of U.S fire related injuries and
death are attributed to smoke inhalation.
Make-up cont..
– Irritants, asphyxiates, and toxins are a few of
the very harmful agents found in smoke.
– The major element of smoke that will be
discussed today will be Asphyxiates.
– Carbon Monoxide and Hydrogen Cyanide are
also two of the most deadly gases present in
a structure fire.
Asphyxiates
Asphyxiates
• Asphyxiates are defined as an agent that
causes death or injury by inhibiting the
body from breathing normally
– This can occur either at the cellular level, by
not allowing oxygen to bind with red blood
cells.
– They can also cause a mechanical reaction
such as swelling/edema of the airway.
Carbon Monoxide
Carbon Monoxide
• Carbon monoxide (CO) is the most widely
known gas that is produced from
combustion.
• CO is produced by the incomplete
combustion of carbon materials and is
both colorless and odorless.
CO cont..
• Carbon Monoxide is an asphyxiate that
exerts its toxic effects by binding to the
hemoglobin of the blood.
• When CO is taken into the body, it will
readily attach itself to the red blood cells.
• CO is around 200-250 times more
effective in binding to red blood cells than
oxygen.
CO cont…
• Carbon Monoxide becomes fatal by
creating systemic hypoxia in all of the
major organs of the body by not allowing
oxygen to on load or off load from the red
blood cells.
• Exposure to low concentrations of CO (170 PPM) have been proven to be relatively
benign.
CO cont…
• People who have been exposed to more
than 70 PPM will start to manifest
symptoms.
• Exposures of 150-200 PPM that are
sustained will result in disorientation,
unconsciousness and/or death.
Hydrogen Cyanide
Hydrogen Cyanide
Hydrogen Cyanide (HC) is now becoming one of
the more studied byproducts of combustion.
Although CO is the usual focus, HC in fire
smoke may be a significant factor in as many as
4000 fire related deaths and 20,000 injuries
each year.
HC is produced by the incomplete combustion of
nitrogen containing substances.
Hydrogen Cyanide cont…
These common materials such as – nylon, wool,
polyurethane, silk, cotton, paper and PVC, as
well as fiberglass insulation are used in all types
of construction of structures and vehicles.
Hydrogen Cyanide cont..
Hydrogen Cyanide is a product of
combustion under burning conditions
where there is high temperature and low
oxygen- The common house fire…..
Each year there are 20,800 residential
structure fires that are attributed to
mattresses, pillows and bedding materials.
– All of which burn two to three times hotter and
faster than conventional materials.
Hydrogen Cyanide cont..
This in turn with the higher temperatures
causes fires to reach flashover faster.
Flashover-the high temp low oxygen
condition that promotes the release of
hydrogen cyanide.
Hydrogen Cyanide
Cyanide is classified as a histo-toxin.
All major organs that rely on oxygen are
severely affected by cyanide poisoning.
Early signs of small concentrations of
cyanide poisoning could be mistaken for
CO poisoning.
The half life of HC is approximately one
hour in blood.
Hydrogen Cyanide cont…
These small exposures mimic CO by Hypoxia
related symptoms- headaches, nausea, light
headedness, anxiety and loss of judgment
Exposures to large concentrations of cyanide
manifest into cardiac arrhythmias (which can be
delayed up to 2-3 weeks post fire exposure),
stupor, coma or seizure that culminate into
respiratory depression and death- The time of
exposure to incapacitation and death is usually
minutes.
Hydrogen Cyanide Cont…
• The primary concerns regarding HC are its
abilities to cause fatal health concerns and
the inability or unavailability of assessing
the problem.
• Niosh has recognized that
electrocardiogram changes can be
observed two to three weeks after a fire
related cyanide exposure.
Hydrogen Cyanide
• This information alone raises many grave
concerns as hundreds of firefighters
succumb to heart attacks at fire scenes
each year.
Hydrogen Cyanide cont…
What is considered a lethal dose?
Hydrogen Cyanide cont…
• 0.2-5.0 PPM
• 10 PPM
• 18-36 PPM
•
•
•
•
•
45-54 PPM
100 PPM
110-135 PPM
180 PPM
280 PPM
Threshold of odor
Maximum safe exposure
Slight symptoms
(headache)
Tolerated for ½ - 1 hour
Fatal -1hour
Fatal in ½ - 1 hour
Fatal in 10 min
Immediately fatal
Hydrogen Cyanide Cont…
• TWA HCN- 4.7 PPM
• IDLH HCN- 50 PPM
CO- 35 PPM
CO- 1200 PPM
Hydrogen Cyanide and Carbon
Monoxide Together
Hydrogen Cyanide and Carbon
Monoxide together
Hydrogen Cyanide has been linked to
increases in fire related deaths due to the
fact of HC being an escape inhibitor.
HC will also cause impairment of a victim
so that they will not be able to think
rationally or to be able to escape the fire.
Low concentrations of HC have been
shown to cause unconsciousness in fire
victims.
HC and CO cont..
The theory of both of the gases working
together is that HC will make escape for
the victim very difficult.
HC will also in turn make the victim lose
consciousness more rapidly.
Studies have shown that the person will
then take in more of the toxic gases, such
as CO, due to increased respirations from
CO and the fact that they are unconscious.
Recognizing Acute Cyanide
Poisoning
Can you identify the possible victims in this picture?
Recognizing Acute Cyanide
Poisoning
Currently there is no diagnostic test to confirm
cyanide poisoning in a rapid manner
Even laboratory blood work performed at the
hospital setting will not reveal cyanide poisoning
in a timely manner
Therefore cyanide poisoning should be
suspected in any person exposed to smoke in a
confined space- i.e. (A room and contents fire)
Signs and Symptoms of Cyanide
Poisoning
•
•
•
•
•
•
•
Rapid Breathing
Dizziness
Weakness
Nausea/Vomiting
Eye Irritation
Pink or red skin color
Rapid heart rate
• Perspiration
• Loss of
consciousness
• Respiratory arrest
• Cardiac Arrest
• Coma
• Seizures
Pre-Hospital Treatment of Cyanide
Poisoning
• Basic life support of the victim includes
removing the person from the source of
exposure
• Restoring or maintaining an open airway
• Administering 100% supplemental oxygen
via NRB or bag valve mask
• Providing cardiopulmonary support and
support of vital signs
Advanced Life Support
• Aggressive advanced airway support such
as intubation may be necessary
• When necessary the administration of
medications for seizures and cardiac
arrest
• If available the administration of a cyanide
antidote kit
Cyanide Antidotes
Cyanide Antidotes
Currently there is only one FDA approved
Pre-Hospital antidote kit available in the
United States
In 2006 the FDA approved Cyanokit for
use in combating cyanide poisoning
The antidote kit that is for sale includes the
drug Hydroxocobalamin as well as
intravenous tubing
Antidotes cont..
The drug hydroxocoblamin is a precursor to
vitamin B-12, a relatively benign substance with
minimal side effects
The mechanism of action binds
hydroxocoblamin to cyanide which then forms
vitamin B-12, a non-toxic compound excreted in
the urine
Cyanokit can be administered to a pt suspected
of cyanide poisoning without fear of any adverse
reactions
Antidote cont…
• The use of Cyanokit has been routinely
used with documented success in Paris
France
• There the Paris Fire Brigade has routinely
given Cyanokit to suspected cyanide
poisoned victims with great success
• From 1998-2002, 81 victims were given
the antidote.
Antidote cont..
• Another study performed by DEY LABS,
the company that produces Cyanokit,
stated that Cyanokit had a 73% success
rate when administered to 69 patients.
• Subjects were over 15 years of age,
presented with soot in the mouth and
expectoration, and had altered
neurological states.
Antidote cont..
Of the 69 patients given Cyanokit, 50
survived
Antidote cont…
Cyanokit also had a 71% success rate
with patients who either accidently or
purposefully ingested/inhaled cyanide as
well
Antidote cont…
The Taylor kit, also referred to as the Lilly
kit or the Pasadena Kit has been used in
the hospital setting for many years.
Although useful it has many adverse side
effects that limit the effectiveness on
smoke inhalation pts
Antidote cont…
Other antidotes that have been in use
outside of the United States for several
years include
– Dicobalt Ededate
– 4-dimethylaminophenol (DMAP)
Detecting Hydrogen Cyanide
Detecting Hydrogen Cyanide
Although HC is one of the most deadly fire
gases produced in a structure fire, most
fire departments do not monitor for it
during an incident
CO is one of the only gases that is
monitored during the mop-up or salvage
and overhaul stage of the fire
So when is it safe to
take off the SCBA?
Proper PPE???
Detection…
Many fire departments allow their
firefighters to doff their SCBA if CO is
found to be at acceptable levels
Although HC may be being produced even
when no flames are visible and there is no
smoke to be seen
Detecting cont…
Currently there are many different
companies that sell air monitoring
equipment for detecting Hydrogen
Cyanide
Multi gas detectors as well as single gas
detectors are currently available
Detecting cont…
The questions that needs to be asked are:
Do we need to monitor for HC during an
incident?
Shouldn’t personnel be wearing their
SCBA during all stages of overhaul and
fire attack?
Summary
Fires in structures today are not the same as
they were even five years ago. With the addition
of synthetic materials, fires burn hotter and more
toxic than ever.
The safest approach to protecting ourselves
from the dangers of toxic byproducts is to
commit to wearing an SCBA for every fire and
for every fire ground duty that is within an IDLH
atmosphere. PERIOD…….
END !!!
References
• DEY LABS- CYANOKITwww.cyanokit.com
• Report of the Investigation Committee into
the Cyanide Poisonings of Providence
Firefighters
• Cyanide Poisoning Treatment CoalitionSmoke Perceptions, Myths and
Misunderstandings
References cont…
• Cyanide and Modern Fires: Scientific and
Practical Fundamentals for Fire Service
Professionals-EMD Pharmaceuticals
• Smoke Inhalation and Cyanide PoisoningJEMS Magazine
• The Hidden List,
www.firefighterclosecalls.com