ToxicAtmospheres
AMMONIA
Colorless gas with penetrating, highly pungent, suffocating odor; can be a liquid
when under pressure.
Characteristics
Danger Level
IDLH 300ppm
Source
Refrigerants, fertilizers.
Facilities using or selling cold storage; fertilizer chemical plant or storage
facilities.
Probable Locations
Tearing eyes, burning throat and eyes, coughing, chest pain, pink frothy sputum,
skin burns, nausea, vomiting, dizziness, fainting.
Physical Reaction
Attacks the respiratory system and eyes; can cause pulmonary edema.
Action On Body
CARBON MONOXIDE (CO)

More fire deaths occur from carbon monoxide (CO) than any other toxic product of combustion.

Odorless, colorless gas present in every fire.

Combines with hemoglobin 200x more readily than does oxygen.(Carboxyhemoglobin, the result, causes
oxygen starvation)

Firefighters can suffer from the effects CO exposure even though they are asymptomatic.

A 1% concentration of CO will cause a 50% level of carboxyhemoglobin in 2 1/2 to 7 minutes. A 5%
concentration can elevate carboxyhemoglobin to the 50% level in 30-90 seconds.

Administering pure oxygen is the most important element in first aid care.
CO (ppm)
CO (% in air)
Symptoms
100
0.01
No symptoms, No damage
200
0.02
Mild headache; few other symptoms
400
0.04
Headache after 1-2 hours
800
0.08
Headache after 45 minutes: nausea, collapse, and
unconsciousness after 2 hours
1,000
0.10
Dangerous-unconsciousness after 1 hour
1,600
0.16
Headache, dizziness, nausea after 20 minutes
3,200
0.32
Headache, dizziness, nausea after 5-10 minutes;
unconsciousness after 30 minutes
6,400
0.64
Headache, dizziness, nausea after 1-2 minutes; unconsciousness
after 15-20 minutes
12,800
1.28
Immediate unconsciousness, danger of death in 1-3 minutes
Headache, dizziness, nausea occur at 1,000-6,400ppm.
Characteristics
Danger Level
Source
Probable Locations
Physical Reaction
Colorless, Odorless gas usually indicated by black smoke.
IDLH 1,200ppm
Concentrations above 0.05 percent (500ppm) can cause unconsciousness and
death without any physiological signs.
Present with every fire.
All Fires.
Headaches, dizziness, weakness, confusion, nausea, vomiting, cherry-red skin.
Causes hypoxia (oxygen starvation) by combining with blood's hemoglobin and
changing the loose combination of oxyhemoglobin to a stronger combination
called
carboxyhemoglobin; combines with hemoglobin about 200 times more readily
than does oxygen.
Action On Body
CARBON DIOXIDE (CO2)

Common gas given off by fire.

End product of complete combustion of carboniferous materials.

Non-flammable, colorless, odorless.

Free-burning fires form more CO2 than smoldering fires.

High CO2 levels are found in CO2 total flooding systems.

Levels higher than 15,000ppm should be avoided.

Because the gas is colorless and odorless, meters should be used in any suspected atmospheres.
CO2 ppm
CO2 % in air
Symptoms
300
0.03
Normal concentration in air
50,000
5.00
Marked increase in respiration, along with headache,
dizziness, sweating, and mental excitement
100,000
10.00
Death within a few minutes due to paralysis of the brain's
respiratory center
Characteristics
Danger Level
Non-flammable, colorless, odorless gas; Can be a liquid or solid.
IDLH 40,000ppm
Concentrations of 10-12 percent are fatal within a few minutes.
Extinguishing agent; common end product of complete combustion.
Source
Probable Locations
Facilities with carbon dioxide total flooding systems; facilities that manufacture
wood alcohol, ethylene, dry ice, or carbonated beverages.
Physical Reaction
Increased respiration, headache, dizziness, sweating, restlessness, and frostbite.
Paralyzes the brain's respiratory center.
Action On Body
HYDROGEN CHLORIDE (HCl)

Colorless gas easily detected by its pungent odor and intense irritation of the eyes and respiratory tract.

Causes swelling and obstruction of the upper respiratory tract.

Breathing is labored and suffocation can result.

Contained in plastics such as polyvinyl chloride (PVC).

Encountered in drug, toy, and general merchandise stores.

Heated concrete can remain hot enough to decompose plastics in telephone or electrical cables.

In the overhaul stage, toxic fumes such as HCI often linger in the structure.
Characteristics
Danger Level
Source
Colorless to slightly yellow gas with irritating, pungent odor.
IDLH 50ppm
Heated plastics, such as polyvinyl chloride (PVC), Containing chlorine.
Drug, toy, and general merchandise stores; telephone and electrical cables;
plastics in the home. (telephone and electrical cables can remain heated enough
after a fire to give off HCl)
Probable Locations
Choking, labored breathing, tearing eyes; burning nose, throat, and skin.
Physical Reaction
Intensely irritates the eyes and respiratory tract; causes swelling and
obstruction of the upper respiratory tract; can result in suffocation.
Action On Body
CHLORINE
Amber liquid or greenish-yellow gas about 2 1/2 times as heavy as air.
Characteristics
Danger Level
IDLH 10ppm
Source
Heated plastics, foam, rubber, synthetic textiles.
Bleach manufacturing plants, water and sewage treatment plants, metal
foundries, swimming pools, pool supply buildings.
Probable Locations
Physical Reaction
Tearing eyes, nose, mouth; weeping eyes, cough, choking, nausea, vomiting,
headache, dizziness, fainting.
Action On Body
Irritates respiratory tract and eyes; reacts with moisture in the lungs to form
sulfuric acid; can cause pulmonary edema and pneumonia.
HYDROGEN CYANIDE (HCN)

Interferes with respiration at the cellular and tissue level.

Classified as a chemical asphyxiant.

Materials that give off HCN are wool, nylon, polyurethane foam, rubber, and paper.

High concentrations of HCN are found at fires in clothing stores, rug shops, or in fires involving aircraft
cabins.

Colorless gas, which has a noticeable almond odor.

Causes gasping respirations, muscle spasms, and increase heart rate up to 100 bpm.
HCN ppm
HCN % in air
Symptoms
135
0.0135
Fatal within 30 minutes
270
0.0270
Fatal almost immediately
Characteristics
Danger Level
Source
Probable Locations
Physical Reaction
Action On Body
NITROGEN DIOXIDE (NO2)
Colorless or pale blue liquid or gas with a bitter almond odor; may be
absorbed through the skin.
IDLH 50ppm
Concentration of 0.0135 percent (135ppm) fatal within 30 minutes;
concentration of 270ppm is fatal almost immediately.
Heated wool, nylon, polyurethane foam, rubber, and paper.
Clothing stores, rug shops, aircraft cabins.
Weakness, headache, confusion, nausea, vomiting, gasping respirations,
muscle spasms, increased heart rate, sudden collapse.
Interferes with respiration at the cellular level by hampering the proper
exchange of oxygen and carbon dioxide; inhibits enzymes by which tissues take
up oxygen, affecting the liver and kidneys.

Nitrogen Oxide ( NO ) readily converts to NO 2 in the presence of oxygen and moisture.

NO2 is a pulmonary irritant that has a reddish brown color.

Commonly called silo gas. (grain bins and silos)

NO2 is also released when pyroxylin plastics decompose.

Common in office supply stores because of drafting tools such as triangles, t-squares, etc. which are
made of pyroxylin plastics.

When inhaled in sufficient concentrations, it causes pulmonary edema that blocks the body’s natural
respiration process and leads to death by suffocation.

All oxides of nitrogen are soluble in water and react with oxygen to form nitric and nitrous acids.

Acids neutralized by the alkalis in the body form nitrites and nitrates which chemically attach to the
blood and can lead to arterial dilation, variation in blood pressure, headaches, dizziness, and delayed
physical reaction.

NO2 is and insidious gas because the irritating effects in the nose and throat can be tolerated even
though a lethal dose is being inhaled.

Symptoms may not appear for several hours.
Characteristics
Dark brown fuming liquid or reddish-brown gas with a pungent, acrid odor.
IDLH 20ppm
Can be tolerated even though a lethal dose is being inhaled.
Danger Level
Source
Fermenting grains, decomposing pyroxylin plastics.
Probable Locations
Physical Reaction
Action On Body
Grain bins, silos, office supply stores.
Cough, frothy sputum, chest pain, variation in blood pressure, headaches,
dizziness, collapse, coma; physical reaction may not be apparent for several
hours after exposure.
Irritates respiratory tract, nose, and throat; arterial dilation; causes pulmonary
edema that blocks the body's natural respiration processes and leads to death by
suffocation; reacts with the moisture in the lungs to form nitrous acids, which in
turn form nitrites and nitrates that attach to the blood and can cause coma.
PHOSGENE (COCl2)

Colorless, tasteless gas with a disagreeable odor.

Produced when refrigerants, such as freon, contact flame.

Strong lung irritant in which the full poisonous effect is not evident for several hours after exposure.

The musty hay odor of phosgene is evident at 6ppm, although lesser amounts cause coughing and eye
irritation.

Twenty-five (25)ppm is deadly.

When phosgene contacts water it decomposes into hydrochloric acid.

Phosgene and the moisture in the lungs also causes it to decompose into hydrochloric acid.

Commonly produced during refrigeration system fires such as air conditioning units, refrigerators, and
freezers.
Colorless, tasteless liquid or gas with a sweet, musty hay odor at low
concentrations; sharp, pungent odor at higher concentrations.
Characteristics
IDLH 2ppm
Odor perceptible at 6ppm; 25ppm is deadly.
Danger Level
Flame contact with refrigerants such as freon; used in some industrial processes.
Source
Appliance stores, supermarkets, meat markets; other facilities containing cold
storage.
Probable Locations
Dry, burning throat; tearing, burning eyes; coughing, foamy sputum, chest pain,
skin burns.
Physical Reaction
Irritates the respiratory tract, skin, and eyes; reacts with the moisture in the
lungs to form hydrochloric acid.
Action On Body
Toxic Atmospheres by IDLH
Carbon Monoxide
1,200 ppm
Hydrogen Chloride
50 ppm
Hydrogen Cyanide
50 ppm
Carbon Dioxide
40,000 ppm
Nitrogen Dioxide
20 ppm
Phosgene
2 ppm
Ammonia
300 ppm
Chlorine
10 ppm
Toxic Atmospheres By Characteristics
Toxic Atmosphere
Color
Odor
Solid, Gas, Liquid
Carbon Monoxide
Colorless
Odorless
Gas
Hydrogen Chloride
Colorless to slightly yellow
Pungent odor
Gas
Hydrogen Cyanide
Colorless or pale blue
Almond odor
Gas or Liquid
Carbon Dioxide
Colorless
Odorless
Liquid or Solid
Nitrogen Dioxide
Dark brown or reddish-brown
Pungent acrid odor
Gas or Liquid
Phosgene
Colorless
Tasteless, sweet musty
hay odor
Gas or Liquid
Ammonia
Colorless
Highly pungent,
suffocating odor
Gas or Liquid under pressure
Chlorine
Amber (liquid) or greenish-yellow
Pungent odor
(gas)
Gas or Liquid
TOXIC ATMOSPHERES W/O FIRE

Sulphur dioxide is a dangerous refrigerant which forms sulphuric acid when it contacts water or
moisture as in the lungs.

Ammonia is a dangerous refrigerant which irritates the respiratory tract and the eyes.

Carbon dioxide (CO2) would be stored at facilities where wood alcohol, ethylene, dry ice, or carbonated
drinks are manufactured.

Chlorine can be found at swimming facilities, in the manufacture of plastics, foam, rubber, and
synthetic textiles, and is commonly found at water and sewage treatment plants.

Rescues in sewers, caves, trenches, storage tanks, tank cars, bins, silos, manholes, pits, and other
confined spaces require the use of SCBA.

USDOT defines a hazardous material as “any substance which may pose an unreasonable risk to health
and safety of operating or emergency personnel, the public, and/or the environment if it is not properly
controlled during handling, storage, manufacture, processing, packaging, use, disposal, or transportation.”

Hazardous materials range from chemicals in liquid or gas form to radioactive materials to etiological
(disease-causing) agents.

Placards should be viewed from a distance when responding to a vehicle or industrial fire.
ToxicAtmospheres ByPhysicalReaction
Toxic Atmosphere
Carbon Monoxide
Headache
Dizziness
Nausea
Vomiting
X
X
X
X
X
X
Coughing
Hydrogen Chloride
Hydrogen Cyanide
X
Carbon Dioxide
X
X
Nitrogen Dioxide
X
X
X
Phosgene
X
Ammonia
Chlorine
Toxic Atmosphere
Carbon Monoxide
X
X
X
X
X
X
X
X
X
Confusion
Weakness
X
X
Hydrogen Chloride
Hydrogen Cyanide
Tearing burning eyes
Chest pain
X
X
X
Carbon Dioxide
Nitrogen Dioxide
X
Phosgene
X
Ammonia
X
Chlorine
X
Toxic Atmospheres by Specific Reaction
Toxic Atmosphere
X
Common Reactions
Specific Reactions
Carbon Monoxide
Headaches, Dizziness, Weakness,
Nausea, Vomiting
Cherry-red Skin, confusion
Hydrogen Chloride
Labored breathing, Tearing eyes
Choking, Burning nose, throat, and skin
Hydrogen Cyanide
Headache, Nausea, Vomiting
Gasping respirations, Muscle spasms, Sudden collapse,
Increased heart rate, Confusion
Headache, Dizziness
Frostbite, Increased respirations, Sweating, restlessness
Headaches, Dizziness, Cough,
Chest Pain
Frothy sputum, Collapse, Coma, Variation in blood
pressure
Phosgene
Coughing, Chest pain
Dry burning throat, tearing burning eyes, Foamy
sputum, Skin burns
Ammonia
Coughing, Chest Pain, Nausea,
Vomiting, Headache, Dizziness
Tearing eyes, burning throat and eyes, Pink frothy
sputum, Skin burns, Fainting
Chlorine
Coughing, Nausea, Vomiting,
Headache, Dizziness.
Tearing eyes, nose, mouth; Weeping eyes, Choking,
Fainting
Carbon Dioxide
Nitrogen Dioxide