Emergency Response to Terrorism:
Tactical Considerations: Hazardous Materials
Student Manual
Unit 3:
Chemical and Physical
Properties
Terminal Objective

Given chemical and physical properties of an unknown
material, the students will be able to estimate risk and to
determine appropriate response actions and precautions.
Enabling Objectives
The students will:

Identify chemical and physical properties of terrorist
agents that relate directly to providing a safe and
effective response.

Identify the mechanisms of harm for Biological,
Nuclear, Incendiary, Chemical, and Explosive (B-NICE)
agents.

Identify various B-NICE dissemination methods and
devices.
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
INTRODUCTION
An understanding of basic chemical and physical properties is important
for the haz mat responder. Chemical and physical properties provide the
true picture of chemical hazards and may allay much of the hysteria
associated with terrorism agents.
PROPERTIES
States of Matter
Basic chemical properties start with the states of matter. The state that a
chemical is in provides some important information about possible tactical
objectives that a haz mat team may employ to mitigate an incident.
Biological agents are typically found in the solid states, but also may be in
the liquid state. The chemical and blister agents can be found as solids,
liquids, or gases. Blood and choking agents usually are found as gases.
From a mitigation strategy standpoint, solids are the easiest to control,
followed by liquids and gases.
Identification of possible agents can be accomplished by the state of
matter, as mustard agent is a solid material at 57F, and presents little risk
in this state of matter. Mustard agent that may be above ambient
temperature does present a greater risk, predominately through contact.
Concentration
When discussing concentration in chemical and physical property terms,
one normally is talking about corrosives. The concentration is the amount
of a given substance in another, typically water. As an example, 98percent sulfuric acid is 98-percent sulfuric acid and 2-percent water, while
20-percent hydrochloric acid has 80-percent water in the mixture. When
discussing terrorism agents, we consider another slant to the definition of
concentration.
In most programs, including this one, the references to the various agents
are for pure substances (or as pure as chemically possible) and not for any
other variations. The probability of finding pure agents is very low, as it is
nearly impossible for a terrorist to produce pure agents. The Aum
Shinrikyo cult in Tokyo used a 30- to 37-percent concentration of Sarin in
its attack of the subway. There are two primary reasons that pure
compounds are not likely to be encountered--ability and safety. With the
exception of ricin, all of the agents must be produced following exact
procedures, using specific scientific or industrial apparatus, and pure
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compounds must be used in order to begin to produce a quality agent.
Generally, the more pure the substance is, the more dangerous it is to
produce, and in many cases, it actually may kill the person trying to
manufacture the agent. Once produced, it must be safe to be placed within
a dissemination device, be transported to a target and be delivered, all
without injuring or killing the terrorist. This does not take into account a
suicide attack, but the probability is that this type of attack is unlikely.
Melting and Freezing Point
Melting points and freezing points are interrelated and, in reality, are the
same thing. There are not two points; rather, the temperature is the
specific number at which a substance freezes or melts, which we will call
the melting-freezing point. In order for a substance to freeze, the
temperature must go lower than the melting-freezing point. In order for
the substance to melt, the temperature must go above the melting-freezing
point.
These points at which a material changes from one state of matter to
another can be an important tactical consideration. At the melting point, a
material goes from the solid state to the liquid state, and at the freezing
point, the material goes from the liquid state to the solid state. One
example: You are at a facility that has a leaking valve from a sulfuric acid
tank, and the leak is a slow drip from the valve. The cap is unable to stop
the flow but it has substantially reduced the amount of product coming
from the valve. At the facility they have dry ice, which could be packed
around the valve. Given that sulfuric acid freezes at 52F (11.1ºC),
packing the valve with dry ice would stop the leak and provide a
considerable time cushion to develop a mitigation strategy further, such as
locating a vacuum truck to offload the tank.
Melting and Freezing Points
Chemical
Ethion
Sulfuric acid
Chlorine
Acetone
Benzene
Toluene
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Celsius
-13
11
-101
-95
6
-96
Fahrenheit
9
52
-150
-138
42
-141
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Vapor Density
Vapor density (VD) is the relationship of a given material to the density of
air, which is given a value of 1. Materials with a VD of less than 1 will
rise in air, whereas materials with a vapor density of greater than 1 will
stay low to the ground. The VD is directly related to the molecular weight
of the material. The higher the molecular weight, the higher the VD.
With one exception (hydrogen cyanide), the warfare agents all have VD's
greater than 1, so will stay low. The higher the VD, the more difficult it is
for the material is to rise up and disperse. On the other hand, the higher
the VD, the harder it is for the material to escape its container.
Vapor Densities (Air=1) and Molecular Weight
Methane
Ammonia
Hydrogen cyanide
Carbon monoxide
Carbon dioxide
Propane
Cyanogen chloride
Chlorine
0.55
0.6
0.93
0.96
1.53
1.56
2.1
2.48
16.5
17
27
28
44
44.1
61.5
70.9
Phosgene
Sarin
Mustard
Tabun
Soman
Lewisite
VX
3.4
4.86
5.5
5.63
6.33
7.2
9.2
98.9
140.11
192.53
162.15
182.20
207.31
267.41
Vapor Risk
All things evaporate, but at a terrorist incident, it is the rate of evaporation
that matters. According to the scientific community, the point at which
rapid evaporation occurs is at 40 mm/Hg. Some use 25 mm/Hg as the
rapid evaporation point, since this is the evaporation point for water.
Boiling Point
The boiling point is important because once the product reaches the
boiling point, it is moving from the liquid state to the gaseous state. It is
defined as the temperature of a liquid at which its vapor pressure is equal
to or greater than the atmospheric pressure of the environment. Once a
product is in the gas state, the ability to cause harm has moved from a
predominately contact hazard that is fairly easy to control to an inhalation
hazard and the gaseous state, which is difficult to control. Once an agent
reaches its boiling point, vapors are being produced and can present a risk
to the responder.
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Vapor Pressure
It is the ability of the material to produce vapors that can cause humans
severe problems. The actual definition is the pressure that is exerted on a
container from the vapors coming from the liquid. Chemicals that have
high vapor pressures generally are referred to as volatiles. The expression
of vapor pressure comes in three forms: pounds per square inch (psi),
atmospheres (atm), and the most commonly used, millimeters of mercury
(mm/Hg). The average vapor pressures of the atmosphere are listed
below.
Normal Vapor Pressures
14.7 psi
1 atm
760 mm/Hg
The use of vapor pressure is fairly common for haz mat responders, but it
is commonly not understood. If a material has a vapor pressure, it has the
ability to cause harm through the inhalation and skin contact routes. If the
material does not have a vapor pressure or has a low vapor pressure, then
the risk to the responder is almost exclusively through actual physical
contact. However, this does not hold true with all chemical agents such as
V-Agent (VX). If the material is a contact hazard only, then a Level A
suit probably is not required. The task to be undertaken will be a factor in
deciding the required level of protective clothing. If you are trying to
mitigate an incident in which a low vapor pressure corrosive liquid was
released from a drum and is on the ground, then a low level of chemical
protective clothing CPC can be used, probably just splash gear. In another
scenario in which the same chemical is released, but is in a tank which is
located above your head and you will be operating below the tank, then a
higher level such as a fully encapsulated suit may be recommended, as a
full body contact may occur. Use the chemical and physical properties
and the task to determine the level of protective clothing required.
Volatility is another term that is used sometimes in conjunction with vapor
pressure. It means the ability of something to evaporate. The military
uses volatility to describe a chemical property of warfare agents. They
also use the term persistency, which is a combination of vapor pressure
and volatility. If an agent is persistent, then once released, it will remain
in place for a period of time. If an agent is nonpersistent, it will evaporate
or dissipate quickly. There are no times associated with this term, but they
generally are described in periods of days. We offer some comparisons in
the text box below.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Persistency of Chemical Agents
Agent
Persistency
Sarin
Non-persistent
Soman
Semi-persistent
Tabun
Semi-persistent
VX
Persistent
Mustard
Persistent
Lewisite
Persistent
Hydrogen cyanide
Non-persistent
Cyanogen chloride
Non-persistent
The chart on the next page lists the vapor pressures for various materials
as well as their associated volatility. Very few information sources list a
volatility for chemicals, but you may find it in some older or more
scientific sources. As can be seen in the chart, volatility follows the vapor
pressure. There is one other item that impacts the volatility of a substance
and that is related to the type of bond that the molecule has. However, in
most cases the vapor pressure/volatility relates to the material's ability to
vaporize and cause harm. One important note is that most vapor pressures
are measured at 20C (70F), and if the measurement temperature differs
for a particular chemical, then the specific temperature is listed.
Chemical
Ethion
Vapor Pressure and Volatility
Vapor Pressure
Volatility
0.0000015 mm of mercury @ 70F 0.031 mg/m3 @ 20C
V-Agent
0.0007 mm of mercury @ 70F
10.5 mg/m3 @ 25C
Sulfuric acid
1 mm of mercury @ 145C
5,362 mg/m3 @ 145C
Sodium hydroxide
1 mm of mercury @ 739C
2,187 mg/m3 @ 739C
Fuel oil #2
2 mm of mercury @ 70F
20,229 mg/m3 at 20C
Sarin
2.1 mm of mercury @ 70F
16,090 mg/m3 @ 20C
Xylene
6.72 mm of mercury @ 21C
39,012 mg/m3 @ 21C
Water
25 mm of mercury @ 70F
22,933 mg/m3 25C
Toluene
36.7 mm of mercury @ 70F
184,908 mg/m3 @ 20C
Nitric acid, fuming
62 mm of mercury @ 70F
213,631 mg/m3 @ 20C
Acetone
180 mm of mercury @ 70F
571,760 mg/m3 20C
Gasoline
300 mm of mercury @ 70F
1,246,607 mg/m3 20C
Hydrofluoric acid
400 mm of mercury @ 70F
437,624 mg/m3 @ 2.5C
Ethyl ether
440 mm of mercury @ 70F
1,783,611 mg/ m3 20C
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We can see that the vapor pressures listed in the chart run from a very low
or, for our purposes, no vapor pressure to some that are considerably
higher. This leads us to the discussion of normal vapor pressure or at what
point a substance becomes a vapor risk. That point is considered to be 40
mm/Hg, according to the scientific community; at that point chemicals
begin to evaporate. Some use 20 mm/Hg but water has a vapor pressure
of 25 mm/Hg. For emergency response purposes, that value may be too
low. Think about a glass of water (8 ounces) that you have set out on a
table. It will take a few days for the water to evaporate. Set out the same
sized glass of gasoline, and that same amount will evaporate in a couple of
hours. A similar glass of ether will evaporate in a few minutes.
Once a material is known to have a vapor pressure that creates a risk, the
next most important factor that affects a material's ability to evaporate is
the temperature. The higher the temperature, the more readily the material
will create vapors. According to the chart, temperature does play a factor,
as most of the listings are for 20 or 25C. To create 1 mm/Hg of vapor,
you need to heat sodium hydroxide to 739C. In reality, we could not
exist in an environment at that temperature. Even at that point, we would
have only 1 mm/Hg of vapor being produced.
As we will discuss in a later unit, the vapor pressure is the key to our
survival; a material that has a vapor pressure of less than 40 mm/Hg
presents little risk to the responder as an inhalation hazard. However, it
still could present a risk to ingest or touch the material. A release of
hydrofluoric acid presents a severe inhalation risk, as it has a high vapor
pressure: 400 mm/Hg at a very low temperature of 2.5C, and one can
imagine what happens at 70F. At that vapor pressure, you have
inhalation, ingestion, and absorption risk. On the other hand, the worst
chemical warfare agent has a vapor pressure of 2.1 mm/Hg, which is
considerably lower than that of water and does not present a vapor hazard.
CHARACTERISTICS OF TERRORISM AGENTS: BIOLOGICAL
As we look at biological agents, you will see some similarities to chemical
agents, but you also will note some significant differences. From a
responder's point of view, the biggest difference is time. Unlike chemical
agents, most of which have an immediate effect, most biological agents
have a delayed effect ranging from several hours to days and, in some
cases, weeks. Therefore, when you respond to a biological incident, there
may be no casualties and nothing significant unless you or someone else
happens to witness the actual release or some type of suspected
dissemination device has been located.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Route of Exposure
Unlike the nerve and blister agents, biological agents cannot penetrate
healthy, unbroken skin. (An exception is T-2 mycotoxin, which causes
skin damage.) To cause disease, most biological agents must be inhaled or
ingested. Our skin provides a good barrier to most biological agents, in
contrast to some chemical agents, which can cause toxic reactions and
symptoms if placed on the skin.
Volatility
Biological agents will be disseminated as either liquid or solid aerosols,
where the biological materials will be subjected to the environment. Many
biological agents are living organisms, and adverse temperature and
humidity will affect them. Sunlight, in particular ultraviolet rays, will kill
many of them. In this environment, most will last only a few hours or
days. Because of this, use of biological agents is more likely at night or in
enclosed areas.
Toxicity
By weight, biological agents are generally more toxic than chemical
agents. For example, ricin, one of the toxins, is two to three times more
toxic than VX; botulinum, another toxin, is 5,000 to 10,000 times more
toxic than VX.
Biological agents generally are


invisible to our senses; and
difficult to detect.
At present, there is only one detector for a small number of biological
agents, but in general there are no simple detectors that can detect and
identify biological agents in time to issue effective warnings. The
detection most likely will occur after the fact, by recognition of the
symptoms in the victims, by growing cultures and then identifying them,
or by other means of testing.
Range of Effects
Biological agents have a variety of effects depending on the organism
involved and how it affects humans, the dose we receive, and the route of
entry. The severity of effects can range from skin irritation to death.
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Natural Sources
Each of the biological agents has a natural host. In some instances, with
little training or equipment, a small amount of culture or material can be
"grown" into larger quantities, which then are placed in a dissemination
device.
Ease of Production
The fact that biological agents are relatively easy to produce ties in to the
fact that they are obtained from nature. The key term here is relatively. If
you can obtain a culture of one of the organisms and know how to "grow"
or culture it (provide a suitable environment, provide nutrients, allow it to
reproduce, etc.), you can increase the quantity using basic procedures with
easily obtainable equipment. In order to maximize the effect of the agent,
it must be military grade or "pure," a level which is very difficult to
obtain. Making anthrax is said to be relatively easy, but making militarygrade anthrax is very difficult.
Delayed Effects
For each living biological agent, a definite time period exists between a
victim's being subjected to the agent and the appearance of symptoms.
This is referred to as the incubation period, the time during which the
agent is reproducing in the body and defeating the body's natural defense
systems. This incubation period can be as short as a few hours or as long
as days and, in some cases, weeks. Even toxins, which do not grow and
reproduce, may take hours to produce symptoms.
Methods of Biological Agent Dissemination and Dispersal
Biological agents may be disseminated by a variety of means. We'll look
at some, but not all, methods here.
One of the most common and effective methods of disseminating
biological agents is through aerosol dispersion to produce an airborne
hazard.
An agricultural sprayer can be used to spray just about anything. A typical
commercial unit has dozens of nozzles that produce a particle size
between 2 and 6 microns. This is an ideal size for spreading biological
agents such as anthrax spores. There are no restrictions on the sale or
purchase of these units, and they are sold all over the world for
agricultural use.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Another means of disseminating biological agents is by contaminating
food, water, or medicine; affecting those who ingest the material.
Terrorists sprayed salmonella on salad bars in the Northwest, which
caused over 700 people to become ill. The terrorists could have used ricin
or some other deadly agent that would have killed those whom the
salmonella merely made ill.
A target may be dermally exposed to a biological agent by direct contact
or injection. The story in the box below relates a recent incident using this
technique.
Georgi Markov was a Bulgarian journalist who wrote in 1968 about
corruption in high government offices in Bulgaria. He was forced to
flee Bulgaria for Italy and eventually England. While living in
London, he continued his reports on Bulgaria and its problems as a
reporter for Radio Free Europe. One morning while waiting for a bus,
he was jabbed in the thigh with an umbrella. His health quickly
deteriorated and he died 4 days later. An autopsy revealed a small
metal pellet near the wound. After analysis, it was found to have
contained less than .01 grams of ricin. This tiny amount was more
than enough to kill him.
A focused response or point source incident involves a single, known
point source of contamination. An example of this would be an individual
standing up in a restaurant or theater, announcing that the glass vial in
his/her hand contains anthrax, and then breaking the vial.
The spraying of salmonella on salad bars in the Northwest resulted in a
public health emergency. Hospital emergency rooms and clinics began
reporting excessive numbers of patients with symptoms of food poisoning.
It took skilled medical detective work to finally trace the illnesses back to
contaminated salad bars and then to trace the contamination to a religious
group that had a dispute with the local area.
In suspicious bombing incidents that do not cause much blast or fire
damage, the bomb may have been detonated for the purpose of
disseminating a biological agent.
Watch also for abandoned spray devices out of place in a particular
environment. They may be key evidence in the eventual investigation, as
well as a clue to the type of hazards you face. Containers from laboratory
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or biological supply houses, and biohazard, culture, or culture media
labels are all indicators of a possible biological agent hazard.
Biologicals and Toxins
Out of the many possibilities for terrorism agents, biological agents and
toxins present the greatest risk to our community. The use of toxins is the
second most popular means of terrorism after explosives. Ricin, one of
the more popular agents, is easy to make and the components can be
purchased easily without arousing any suspicion. Unfortunately,
biological agents are very difficult to detect, and identification relies on
lab testing for confirmation. Biological weapons are organic in nature.
The pathogenic effects may be caused by the actual organism or by its
spores, which are protected reproductive packets. Toxins produced by
living organisms also may be used as weapons, many with lethal results.
Bacteria and viruses are both organisms with direct pathogenic effects.
Bacteria are single-celled microscopic organisms with a nucleus and a cell
wall. Bacteria that are dangerous to humans (and hence, possible terrorist
weapons) include those that cause anthrax, the plague, tularemia, and
cholera. Viruses are extremely small submicroscopic agents with a
protein coat of either ribonucleic acid (RNA) or deoxyribonucleic acid
(DNA), and in most cases, these agents require a host to reproduce.
Dangerous, and sometimes deadly, viruses include viral hemorrhagic
fevers, Venezuelan equine encephalitis (VEE), and smallpox.
Toxins are produced from living organisms, such as beans and plants.
Ricin is a toxin derived from the beans of the castor plant, and its
inhalation or ingestion can lead to death. Abrin is a similar toxin, but it is
75 times more powerful than ricin. Botulinum toxin (Bot Tox) is made
from bacterial byproducts and is a highly potent toxin. It is 3,000 times
more powerful than ricin and 100,000 times more powerful than sarin.
Mycotoxins are also dangerous biological toxins. These toxins can be
introduced via almost any route, including absorption through skin
contact. Their effects are similar to those of blister (mustard) agents,
except that symptom onset is more rapid, usually occurring within
minutes. Because these toxins are not sensitive to heat or ultraviolet light
(unlike viruses and many bacteria), mycotoxins could be used effectively
as terrorist weapons.
Bacteria
Bacteria can cause diseases in humans and animals by invading tissues or
by producing toxins. In some cases, they will present both types of attack
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
on the body. The common bacterial agents are bacillus anthracis
(anthrax), vibrio cholerae (cholera), Yersinia pestis (plague), francisella
tularensis (tularemia) and coxiella burnetii (Q fever). See Appendix F for
more information regarding these agents.
Viral Agents
Viruses are the simplest type of microorganism and consist of an outer
shell composed of either RNA or DNA. Viruses are unable to live on their
own and rely on a host to stay alive. The host can be human, animal,
plant, or bacteria. The most common agents are VEE, smallpox, and viral
hemorrhagic fevers (Ebola is one example).
Biological Toxins
Biological toxins are produced from a plant, animal, or microbe, and are
naturally occurring. With the exception of mycotoxins, they are not
absorbed through the skin, but must be inhaled, injected, or ingested.
Although these agents are the easiest to obtain, typically by home
manufacture, their effectiveness can be limited. They are in some cases
very toxic, but the distribution method required limits their use. The
military has not adopted the use of biological toxins, as it requires too
much agent to be effective. Due to the toxicity, large quantities cannot be
produced. Ricin is a toxic protein extracted from the castor bean seed. It
is by far the most popular, and unfortunately, the easiest to produce. Ricin
is the deadliest plant toxin known and can be difficult to detect in an
autopsy, as it is a naturally occurring protein. See Appendix F for more
information regarding these agents.
Other Plant Poisons











precatory beans (a.k.a. jequirity beans);
water hemlock;
tung-oil tree;
oleander;
yellow oleander;
alkaloids;
tobacco;
yew;
monkshood;
zigadenus;
potato sprouts;
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

woods hemlock; and
autumn crocus.
Poisonous Mushrooms


galerina autumnalis and venenata; and
cortinarius orellanus.
Not-So-Poisonous Plants









poinsettia;
holly;
wisteria;
rhubarb leaves;
christmas rose;
lily-of-the-valley;
lupine;
mistletoe; and
fly agaric.
Natural Poisons
Digitalis--heart medication derived from the foxglove plant, using vodka.
Rapeseed oil--used in paint industry.
Jequirity bean--rosary pea or crab's eye. Abrin is the poison in the middle
of the shell.
Shellfish toxin--also known as saxitoxin or gonyaultoxin. Some of the
chemicals used in the production of shellfish toxin include shellfish,
acidified alcohol, hydrochloric acid, ethyl alcohol (grain alcohol or
denatured alcohol) and charcoal powder.
Time-Delay Poisons
In the text Silent Death, one chapter describes the use of time-delay
poisons. The author describes the use of naturally available poisons as
well as commercially available materials. There is some additional
discussion regarding the use of carcinogenic materials to cause a slow
death. The author describes the use of medical-grade radioactive materials
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
to poison someone slowly. Even the author admits these materials are
easy to obtain, and he describes the best way to obtain them and use them
in a plot to kill someone. Some of the materials described in this text are
listed in the table on the following page.
Potential Time-Delay Poisons
Jequirity bean
Propiolacetone
N-nitrodimethylamine
Dimethylaminoazobenzene
Benzidine
4-aminodiphenyl
Phosphorus isotope (P32)
O-toluidine
4-nitrodiphenyl
Beta-napthylamine
Dichlorobenzene
2-acetylamino-fluorine
Bracken fern
Calcium isotope (Ca45)
NUCLEAR AGENTS
Sources of Radioactive Materials
Radiation comes from outer space, the ground, and even from within our
own bodies. Radiation is all around us and has been present since the
birth of this planet. Radiation occurs naturally and in sources produced by
humans. The table below shows some sources of radiation.
Sources of Radioactive Materials
Radiation Source
Gastrointestinal series (upper and lower)
Radon in average household in the U.S.
Living in Denver
X-rays and nuclear medicine
Natural radioactivity in the body
Living in Chicago
Cosmic radiation
Mammogram
Living at sea level
Consumer products (such as drinking water)
Chest X-ray
Living near a nuclear power station
Relative Dose (Millirem)
1,400 millirem
200 millirem annually
81 millirem annually
50 millirem annually
39 millirem annually
34 millirem annually
31 millirem annually
30 millirem
28 millirem annually
11 millirem annually
10 millirem
less than 1 millirem annually
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Radiation used in medicine is the largest source of human-produced
radiation to which we are exposed. Most of our exposure is to diagnostic
X-rays--Americans receive 200 million X-rays every year. Radiation also
is used in cancer treatments. One-third of all successful cancer treatments
involve radiation.
Nuclear power plants use radioactive materials (uranium) to generate
electricity, and any activity that uses radioactive materials generates
radioactive waste. Mining, nuclear power, defense, nuclear medicine, and
scientific research all produce radioactive waste that must be disposed of
properly.
Radiation Exposures
Over 80 percent of our exposure to radiation comes from natural sources.
Fifty-five percent of our exposure to natural sources of radiation usually
comes from radon. Radon is a colorless, tasteless, and odorless gas that
comes from the decay of uranium found in nearly all soils. Our own
bodies, which contain and concentrate the radioactive element potassium,
account for 11 percent of our total exposure. Another 3 percent of our
exposure to radiation comes from consumer products. The average annual
radiation exposure for persons living in the United States is 360 millirem.
Radiation overexposures sometimes are reported, as listed in the table
below.
Radiation Overexposures Reported by NRC (1994-1995)
Type of Licensee
Number of Individuals
Medical/Academic
4
Research/Commercial
37
Industrial Radiography
16
TOTAL
57
Source: Annual Report, 1994--FY 95, Nuclear Materials, Office for Analysis
and Evaluation of Operational Data, U.S. Nuclear Regulatory Commission
The primary causes of medical/academic and research/commercial
overexposures included failure to ensure that adequate dosimetry was
issued and monitored, failure to wear adequate protective clothing in areas
containing discrete radioactive particles, and failure to follow procedures.
The primary causes of industrial radiography exposure are failure to
conduct the required radiation surveys, failure to set up or monitor
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
radiation boundaries, failure to follow established emergency procedures,
and lack of adequate supervision of assistants.
Types of Radiation Injuries
There are three types of radiation injuries: external irradiation,
contamination, and incorporation.
External irradiation occurs when all or part of the body is exposed to
penetrating radiation from an external source. A similar thing occurs
during an ordinary chest X-ray. A person who has been exposed to
radiation from an external source, but has not been contaminated by the
radioactive material, is not radioactive and presents no danger to
emergency responders.
Whole-body (total) exposure occurs when the entire body is irradiated
from an external source. In addition, when a radioactive material is
uniformly distributed throughout the body tissues rather than being
concentrated in certain organs, the irradiation can be considered wholebody exposure as well as contamination.
Local exposure occurs when a radioactive material is concentrated in
certain organs or body parts, or when a local portion of the body is
irradiated, such as a hand.
External contamination means that radioactive materials in the form of
gases, liquids, or solids are released into the environment and contaminate
people externally, such as on skin and clothing. This type of
contamination is the easiest to remove.
Internal contamination refers to radioactive materials taken up into the
body and being contained in the gut, lungs and blood or extracellular
fluids. This requires the radioactive materials to enter through a "portal of
entry" such as the mouth, nose, eyes, wounds, or other skin breaks. The
vagina and anus also can serve as portals of entry if the mucosa become
contaminated. Intact skin forms a good barrier against most forms of
radioactive materials.
Incorporation refers to the uptake of radioactive materials by body cells,
tissues, and target organs such as bones, liver, thyroid, or kidney.
Radioactive materials are distributed throughout the body based on their
chemical properties. Incorporation cannot occur unless contamination has
occurred. Incorporation can occur rapidly, within as little as an hour or
less. This is the most difficult type of contamination to remove.
Radioisotopes have chemical properties essentially identical to their stable
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counterparts. For example, a thyroid cell will take up I-131 and use it to
make thyroid hormone just as it would stable I-127. The cell will be
unable to tell the difference until the I-131 decays to Xe-131, emitting a
beta particle and gamma radiation.
Atomic Structure
Elements are substances that cannot be broken down into simpler
substances by any chemical means. There are 105 known elements, each
with specific characteristics. The atom is the simplest unit into which an
element can be divided and still retain the specific properties of the
original element. Molecules are combinations of two or more atoms.
Each element is identified by a one- or two-letter symbol, such as O for
oxygen, He for helium, Pb for lead, etc.
Atoms are composed of a central nucleus, containing most of the atom's
mass, and electrons orbiting in shells around the nucleus. The nucleus
consists of a number of fundamental particles, the most important being
protons and neutrons. The number of protons determines the type of atom
or the element (hydrogen, oxygen, etc.) and also equals the atomic
number. Most atoms are stable, although some are unstable. Unstable
atoms attempt to stabilize by emitting energy from their nuclei in the form
of ionizing radiation. Atoms that emit ionizing radiation are radioactive.
Neutrons are uncharged particles having a mass slightly greater than that
of a proton, approximately equal to the masses of a proton and an electron.
They interact directly with atomic nuclei. Because of their mass and
energy, neutrons can cause severe disruptions in atomic structure. (In
addition, they have the ability to convert stable isotopes to radioisotopes.)
Ions
Atoms are electrically neutral when the number of negatively charged
electrons orbiting the nucleus equals the number of positively charged
protons within the nucleus. When the number of electrons is greater than
or less than the number of protons in the nucleus, the atoms are not
electrically neutral and carry a net negative or positive charge,
respectively. At this point they are called ions and tend to combine with
other ions of opposite net charge to form a neutral molecule.
Ionizing Radiation
Ionizing radiation is radiation that can produce charged particles (ions) in
any material it strikes. These charged particles can cause damage to
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
molecules, cells, or tissues. The three most common types of ionizing
radiation are alpha particles, beta particles, and gamma rays.
Radiation Energy
Each type of radiation can be emitted with various levels of energy,
measured in mega electron volts (MeV). The type of radiation and its
energy are unique to the type of radioactive material and can be used to
identify it.
Alpha () particles are positively charged particles consisting of two
protons and two neutrons all strongly bound together by nuclear forces.
They are the heaviest of the radioactive particles. Alpha particles have a
mass about 7,000 times the mass of electrons and are ejected from the
nuclei of radioactive atoms with one or several characteristics and discrete
energies. Alpha particles are the least penetrating of the three types of
ionizing radiation. They do not penetrate the dead layer of skin and can be
stopped by a piece of paper or clothing. They are not, however, a "safe"
type of radiation. They are energetic particles that transfer their energy
over a short distance, doing a great deal of damage. A health hazard may
occur when alpha-emitting materials are inhaled or swallowed, or enter the
body through a wound, depositing themselves near or in cells where the
energetic alpha particles will do extensive damage when released. Thus,
alpha particles are an internal hazard only.
Beta () particles are high-speed charged particles with a moderate
penetrating power. These particles have the characteristics of electrons,
and can be positively or negatively charged. Beta particles can travel
several hundred times the distance of alpha particles in the air and can
penetrate into skin and cause severe skin burns. Thus, beta particles can
be an external and an internal hazard because they can injure both the
outside and inside of the body. They require fairly thin (a few
millimeters) shielding such as thin metal, wallboard, or heavy clothing to
stop them.
Gamma (  ) rays are electromagnetic radiation emitted from the nucleus
of a radioactive atom. Gamma rays are the most penetrating type of
radiation and can travel many meters to miles in air and many centimeters
in tissue, doing damage to deep organs. Because gamma rays can travel
through the body, they sometimes are referred to as "penetrating
radiation." Like emitters of beta particles, gamma rays constitute both an
internal and an external hazard.
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Characteristics of Types of Radiation
Type of source
Alpha
Beta
Gamma (similar to
X-rays)
Neutrons
Movement/Energy
Only travel 1 to 2
inches; are a
respiratory and
ingestion hazard.
Lose energy quickly.
Travel up to 10 feet,
and hold their energy
longer than alpha.
Several hundred feet.
Several hundred feet.
Target organs
Kidneys, liver,
lungs, and skeletal
system.
Shielding
Heavy clothes,
respiratory
protection.
Eyes, internal
organs. Skin burns
possible from high
levels.
Internal organs and
tissues.
Skin hazard.
Aluminum, other
metals, plastic, or
glass.
Lead, concrete,
steel.
Water or plastic.
Isotopes and Nuclides
Isotopes
Isotopes are forms of the same element that differ by the number of
neutrons in the nucleus. Since they are the same element, they have the
same number of protons, and thus the same atomic number. Since the
number of neutrons is different, the atomic mass number (number of
protons and neutrons) will be different; this is how the isotope is
identified. For example, hydrogen has three isotopes, with one, two, and
three atomic mass units (one proton each, plus 0, 1, and 2 neutrons,
respectively). H-1 is "normal" hydrogen; H-2 and H-3 are commonly
called deuterium and tritium, respectively. The first two of these are
stable (nonradioactive), but tritium is a radioactive isotope. Isotopes are
identified by their symbol and mass number, as in H-2, etc. They also can
be written as hydrogen-2, or 2H. The atomic number also may be
included as a subscript.
Nuclides
The central core of an atom is the nucleus and contains nearly all of the
atom's mass. Different types of nuclei are called nuclides. For example,
the nucleus of an I-131 atom is called its nuclide. In common use, isotope
and nuclide are used interchangeably. A nuclide is characterized by its
mass number as well as its atomic number.
The terms "radioisotope" and "radionuclide" merely denote the radioactive
forms.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Radioactivity
Radioactivity is a process whereby an unstable nucleus attempts to
stabilize through the emission of energetic particles (alpha, beta, neutron)
and/or pure energy (gamma). Emission of an alpha particle results in the
loss of two neutrons and two protons. This produces a new element
because these particles are being ejected from the nucleus. These new
atoms are called "daughters," and the process is called nuclear decay or
disintegration. Sometimes the process is successful in producing a stable
atom as in the transformation of I-131 to Xe-131 by emission of a beta
particle. Sometimes, however, several decays are needed to produce a
stable daughter, as in the decay of Uranium (U), which will undergo more
than 10 decays before it finally becomes stable lead (Pb). Every decay
produces a new daughter.
Measuring Radioactivity
When dealing with radiation, it is important to know how much radiation
is present and the extent of exposure over a period of time. Radioactivity
is measured in units of quantity, dose, and exposure as described below.
Units of Quantity (Amount) of Radioactive Material
Different radioactive materials emit very different amounts of
radioactivity. Thus, conventional units of mass or weight such as the
kilogram or pound do not relate to the amount of radiation being emitted
from a sample of radioactive material and are not effective units to
measure quantity. The curie (Ci) measures the amount of radioactive
material based on the amount of radiation emitted and allows better
comparison of different types of radioactive materials. One curie of
radioactive material is defined as the amount of radioactive material
undergoing 37 billion decays per second.
The international system of units is based on the meter (length), kilogram
(mass), and the liter (volume), and is known as Systems International (SI).
The SI unit corresponding to the curie is the Becquerel (Bq), and it is
defined as an amount of radioactive material undergoing one decay per
second: 1 Ci = 37 GBq.
Millicurie (mCi)--One thousandth of a curie.
Microcurie (Ci)--One millionth of a curie.
Megabecquerel (MBq)--One million Bq.
Gigabecquerel(GBq)--One billion Bq.
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Units of Absorbed Dose
Dose means the total amount of radiation or energy absorbed. Absorbed
dose is the energy imparted to matter by ionizing radiation per unit mass
of irradiated material at the place of interest. The total dose = dose rate 
exposure time. For example, 25 R/hr (dose rate)  1/2 hour (exposure
time) = 12.5 R (total dose).
Radiation absorbed dose (Rad) is a measure of the energy deposited in
matter by ionizing radiation or, in other words, an indication of how much
immediate damage radiation causes to matter.
The SI unit for measuring dose is the Gray (Gy). 1 Rad = 0.01 Gy, or 100
Rad = 1 Gy.
Units of Exposure
Roentgen (R) is a measure of how much charge due to ionization is
produced in a volume of air by X-radiation and gamma radiation only.
Roentgen equivalent man (rem) is a measure of the amount of damage
caused by radiation passing through human tissue. Different types and
energies of radiation are capable of causing different degrees of damage.
For example, alpha radiation is more capable of causing biological
damage to the tissues that it interacts with than is gamma radiation. The
rem attempts to give an easy way of equating the ability to cause
biological damage. Rem is calculated by multiplying Rad by a factor that
accounts for the differing abilities to cause damage.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Effects of Radiation
Amount (rem)
0-25
25 to100
100 to200
200 to300
300 to600
Effect
None, possible delayed effects.
May cause some sickness in some persons,
delayed effects not common.
Lower doses cause nausea and fatigue.
Higher doses may cause vomiting. Longterm effects may include life-expectancy
shortening.
Nausea and vomiting, other effects can last
up to 2 weeks.
Nausea, vomiting and diarrhea are
immediate, a lull in symptoms, typically
lasting a week, may occur with returning
symptoms. Exposure over 450 may be
fatal, with death usually occurring within 2
to 6 weeks. Fatalities have occurred in half
of those exposed to more than 450 rem.
The SI unit for measuring radiation damage is the sievert (Sv). 1 rem =
0.01 Sv or 100 rem = 1 Sv.
The sievert (Sv) and rem are health effects-related measurements of
absorbed radiation.
Exposure (Dose) Rate
The exposure (dose) rate is the amount of radiation exposure per unit of
time, usually per hour. The exposure rate generally is expressed in
roentgens per hour or in milliroentgens per hour on most of the
instruments commonly used.
Elements of Radiation Protection
There are three basic radiation protection principles that can be employed
to reduce exposure to ionizing radiation. These principles are based on
consideration of three radiation protection factors that alter radiation dose:
time, distance, and shielding.
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Time
Time is an important factor in radiation protection. The shorter the time
spent in a radiation field, the less radiation is absorbed by the body.
Depending on the activity present, radioactive material will emit a known
amount of radiation per unit time. Obviously, the longer a person remains
in a radiation field, the more radiation the person will absorb into the
body.
Distance--Inverse-Square Law
The inverse-square law states that the radiation dose rate changes
inversely by the square of the change in the distance. For example: The
dose rate at 3 feet is 20 R/hr. Increase the distance by a factor of 2 (to 6
feet), the dose rate changes by a factor of 22 or 4, and the dose rate is 5
R/hr. Triple the distance from 3 to 9 feet, and the dose decreases by a
factor of 32 or 9. The dose rate then would go from 20 R/hr to 2.2 R/hr. It
also works in reverse--decrease the distance by 1/2 and the dose rate
quadruples. Go from 6 to 3 feet, and the dose rate goes from 5 to 20 R/hr.
The farther a person is from the source of radiation, the lower the radiation
dose.
Shielding
The denser a material, the greater its ability to stop the passage of
radiation. In most cases, high-density material such as lead is used to
shield from radiation. Portable lead or concrete shields are used
sometimes when responding to accidents where contamination levels are
very high. In emergency management of the contaminated patient,
shielding is limited to protective clothing. Protective clothing will protect
the individual against contamination and also will stop the passage of all
alpha and some beta radiation. However, it does not stop penetrating
gamma radiation. In the emergency response arena, shielding is limited to
anti-contamination measures, and the principles of time and distance are
used to reduce radiation exposure. Lead aprons used by X-ray
departments are only partially effective, as they are too thin to offer full
protection.
As Low As Reasonably Achievable
This principle states that all efforts should be aimed at keeping the
radiation exposure As Low As Reasonably Achievable (ALARA). By
using radiation protection principles, emergency responders can minimize
their own radiation exposure. All activities should be guided by the
ALARA concept.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Emergency Response Exposure Limits
The following are the recommended dose limits for workers performing
various emergency services as defined by the Environmental Protection
Agency (EPA). These are legally established limits. They should not be
considered safe limits that can be accumulated with impunity, because
they still present some risk. Strive to maintain ALARA.
Recommended Environmental Protection Agency Limits
The recommended dose for emergency response efforts is a total dose of
no more than 25 rems for any single life-threatening emergency. Your
employer may mandate even lower levels.
Emergency Response Exposure Limits
Dose Limit
(rem)
5
10
25
>25
Activity
All
Protecting valuable property
Lifesaving or protection of large
populations
Lifesaving or protection of large
populations
Condition
Lower dose not practical
Lower dose not practical
Only on a voluntary basis to
persons fully aware of the risks
involved
Source: EMI/FEMA. 1994. Fundamentals for Radiological Response Team Course
Yearly Maximum Permissible Dose for Radiation Workers
The Nuclear Regulatory Commission sets yearly radiation exposure limits
for various categories of exposed persons. These are legal limits that are
not to be exceeded at any time. These limits are published in 10 Code of
Federal Regulations (CFR) 20, Occupational Limits for External
Exposure.
Yearly Maximum Permissible Dose for Radiation Workers
Whole body
5 rem
Hands, forearms, etc.
75 rem
Skin of the whole body
30 rem
Pregnant radiation worker (fetus)
0.5 rem for single exposure
Nonradiation worker or public
0.1 rem
Source: EMI/FEMA. 1994. Fundamentals for Radiological Response
Team Course.
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Basic Protection for the Types of Radiation
There are thousands of potential nuclear materials that are too numerous to
list here. The following chart indicates protective measures indicated for
general types of radiation.
Basic Protective Measures
Type of Radiation
Alpha
Beta
Beta (high energy)
Gamma
Protection
Heavy clothes, respiratory protection
Heavy clothes, respiratory protection
Shielding
Shielding
INCENDIARIES
Incendiary devices have been used by terrorists for centuries. Fire is a
flexible tool that is capable of causing property damage and loss of life
and sparking panic among the public. It also will continue to spread and
cause damage until all available fuel is consumed or the fire is
extinguished.
The Irish Republican Army (IRA) has used incendiary devices throughout
Europe for many years, resulting in deaths, injuries, and tremendous
monetary losses.
In the United States, the use of incendiary devices is on the rise.
According to data from the Federal Bureau of Investigation (FBI) Bomb
Data Center:

Incendiary devices were used in approximately 20 to 25 percent of
all recorded bombing incidents in the United States.

When used, incendiary devices ignited approximately 75 percent
of the time.

Less than 5 percent of actual or attempted bombings (including
those involving incendiaries) have been preceded by a threat.
Classification of Incendiary Devices
Incendiary devices can be classified in a number of ways. Two common
classifications involve triggering and delivery methods.
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
There are several different means of triggering the incendiary reaction.
Chemical reactions, including burning fuses, are a staple of the trade.
Electronic ignition through a variety of relays, switches, and other devices
is another means. Finally, mechanical ignition may be used to initiate the
event.
Modes of delivery can include hand-thrown devices like Molotov
cocktails, stationary or planted devices, and self-propelled incendiaries
like rockets or flare gun projectiles.
Components of Incendiary Devices
Incendiary devices have three components. An ignition source is needed
to initiate the incendiary reaction. Combustible filler material provides the
bulk of the material that actually ignites, and a housing or container is
required to hold the filler.
Materials Used to Construct Incendiary Devices
Incendiary devices may be constructed from a wide variety of materials.
Some of the products that have been used to construct incendiary devices
include









roadway flares;
gasoline and motor oil;
light bulbs;
common electrical components and devices;
matches;
household chemicals;
fireworks;
propane and butane cylinders; and
plastic pipes, bottles, and cans.
CHEMICAL AGENTS
This section discusses the military chemical agents on which much
attention has been focused. Chemical weapons are made from substances
that can produce injury or death. Types include nerve agents, blister
agents, blood agents, choking (pulmonary) agents, irritants (riot control
agents), and industrial chemicals. As was discussed in the introduction, it
is unlikely that these agents would be used by a terrorist but, as haz mat
responders, we should know the facts about these agents and their
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chemical and physical properties. A hoax incident will be a very difficult
incident to handle if all of the facts surrounding the chemicals are not
known.
Many of the military agents are similar to many of the products we see
today, and some of the chemicals that haz mat teams respond to are more
deadly. It is the intended use of these military agents that adds a
heightened fear factor. A haz mat team that has responded to a technicalgrade pesticide incident has matched the toxicity and the chemical and
physical properties of an incident involving a nerve agent. The difference
would be that the use of nerve agent could mean that people are the target
and could become victims, and that the incident is now a crime scene.
General Information about Chemical Agents
Chemical agents have several properties:






generally liquids when containerized;
normally disseminated as aerosols or as gases and will dissipate
over time;
can have varying effects on the body ranging from irritation to
death;
produce symptoms with onset times ranging from seconds to
several hours;
influenced by weather conditions (temperature, wind speed, wind
direction, humidity, and air stability); and
can be protected against, treated, and decontaminated.
Dissemination Methods
Chemical agents are typically dispersed via an aerosol solution. An
aerosol is defined as a suspension or dispersion of small particles (solids
or liquids) in a gaseous medium. Aerosol dissemination methods range
from hand-held spray bottles and backpack pesticide spray equipment to
powered generators carried by trucks, ships, and aircraft.
Military Designations
The military uses its own designation for these materials, even if they are
in common industrial use. In many cases, the designation comes from the
inventor of the agent, and in others, the country that developed it.
Although it would be preferable to discuss these agents using their
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
common names or their chemical names, this would cause some problems,
as most military detection equipment uses the military designations. Until
such time as these detection devices become more adapted to the civilian
world, we should use the military designations.
Military Designations of Chemical Weapons
Military
Designation
GA
GB
GD
VX
Nerve
Nerve
Nerve
Nerve
H
S-mustard
N-mustard
HD
L
CX
CK
AC
CL
CG
CR or CS
CN
OC
None designated
Blister
Blister
Blister
Blister
Blister
Blister
Blood
Blood
Choking
Choking
Irritant
Irritant
Irritant
Irritant
Agent Category
Agent Name
Tabun
Sarin
Soman
V-Agent (X is the number in the
series)
Mustard
Sulfur mustard
Nitrogen mustard
Thickened mustard
Lewisite
Phosgene oxime
Cyanogen chloride
Hydrogen cyanide
Chlorine
Phosgene
Tear gas
Mace
Pepper spray
Combination mace/pepper
Toxicity Terms
Standard exposure values are provided for the chemical agents, but the
military includes some additional terms that may not be in common use.
As one would expect, the military has done extensive studies regarding the
toxicity of these agents, and much of the data that we use for exposure
guidelines was derived from their testing.
The military uses the standard exposure guidelines but to the Lethal Dose
(LD50) and Lethal Concentration (LC50) they add the element of time.
This is expressed as LCt50 and LDt50. This time element is expressed in
minutes, typically 1 minute. Another term used is incapacitating
concentration (IC50), which provides a relative amount that would be
needed to incapacitate 50 percent of the exposed population.
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The military also uses an Airborne Exposure Limit (AEL), which is the
term used to describe the military exposure guidelines. Employees cannot
be exposed to more than this level without the use of respiratory
protection.
Chemical Agent Categories
Chemicals used by the military are divided into five basic categories-blister, nerve, choking, blood, and incapacitating agents. The categories
accurately portray the target area of concern. Not all of these agents were
designed to kill; some were designed just to slow troop movement. Many
of these agents have civilian uses within industry and are commonly used
throughout the Nation. Each type of agent is discussed further in the
following sections.
Choking Agents
The two most common agents in this category should be very familiar to a
haz mat responder, as they are chlorine and phosgene. Both of these are
used widely in the industrial community, but chlorine is found in almost
every community and is easy to obtain or produce. Both of these agents
were used in World War I with great effectiveness. Their drawback was
that they were nonpersistent and moved away quickly.
Blood Agents
As their name implies, these agents attack the blood, preventing the body
from using the oxygen molecules in the blood stream. As is commonly
known, hydrogen cyanide is used in the gas chamber to carry out
executions, and if applied with the correct dose, is very effective. When
exposed to high concentrations, the victim(s) will choke for air, develop
reddish skin, and begin vomiting. After a few minutes, unconsciousness
and death will occur. Using the range of "how to" books, the recipe
necessary to carry out an attack with hydrogen cyanide is relatively easy to
execute. With some work, the ingredients necessary could be found in
some industrial locations and college labs.
Blister Agents
Blister agents also were used in World War I, and were used more widely
as the military developed the means to protect against the respiratory
hazard presented by the choking and blood agents. Since blister agents
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UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
affect both the skin and the respiratory system, they were a natural
progression into a new type of agent, one that was difficult to protect
against.
The categories of blister agents are mustard, lewisite, and phosgene
oxime, although there are a number of variations of mustard agent.
Military Designations of Mustards
Name
Mustard
Mustard distilled
Nitrogen mustard
Thio mustard
Military Designation
H
HD
HN
HT
All of these agents have the ability to act quickly, but at lesser
concentrations their effects will be delayed. Mustard presents some
problems, as it causes no pain or irritation at low concentrations for a
period of 4 to 24 hours. Both mustard and lewisite are carcinogens. Both
lewisite and phosgene oxime produce quick reactions to an exposure as
they both cause irritation and pain upon contact. If the liquid or vapors are
inhaled, blisters will begin to form in the respiratory system and cause
lung damage.
Nerve Agents
Nerve agents all share certain properties. All act on the nervous system
and are composed of chemicals similar to those found in commercial
organophosphate pesticides. Common nerve agents include tabun (GA),
sarin (GB), soman (GD) and V-Agent (VX).
Like all organophosphates, nerve agents are cholinesterase inhibitors.
Cholinesterase is an enzyme that removes the neurotransmitter
acetylcholine from the small gap between nerve cells (synapse). As a
result of cholinesterase inhibition, acetylcholine accumulates in the
synapse and is interpreted as another nerve impulse. In simple terms, the
nerve agent creates a gap so that the electrical impulses of the body cannot
function. Exposure to nerve agents, causes miosis (pinpoint pupils),
muscular tremors, convulsions, and DUMBELS syndrome (diarrhea,
urination, miosis, broncospasm [wheezing], emesis, lacrimation,
salivation), and ultimately results in death from exposure.
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All nerve agents also share a high vapor density when compared to air
(vapor density = 1). The lightest nerve agent, sarin (vapor density of
4.86), is almost five times heavier than air, while the heaviest, V-Agent
(vapor density of 9.2), is over nine times heavier than air. This means
these agents will sink rapidly to the ground unless there is some
mechanical means to push them up (vaporizers, fans, etc.). They will tend
to migrate to below-ground locations such as subways, basements, tunnels,
etc.
Nerve agents also display very low volatility, which means that they
produce little vapor, as compared to other substances. This is not to say
that they are not very toxic materials. They are to be considered extremely
toxic; it's just that physical contact must be made with the liquid to cause
harm. In order for these nerve agents to have an effect on large numbers
of people, they must be distributed effectively. So far the only effective
method of distribution known is in an artillery shell that is detonated over
troops in an open field, and even that method is not 100-percent effective.
There has been discussion about methods of distribution such as sprayers
and other mechanical devices. Given the chemical and physical properties
of these agents, effective distribution is very difficult, but is always
possible. The key items working against a terrorist are vapor pressure,
molecular weight, vapor density, and instability in water/humidity.
The other item that is up for discussion is the level of difficulty involved
in making these agents. The Aum Shinrikyo cult had a full-scale
production area to make Sarin agent. They also were backed by millions
of dollars in assets. The chemicals required to make Sarin are not
obtained or manufactured easily. To produce sarin takes an educated
person with all of the equipment and the ability to produce it undetected.
Is it possible for someone to make Sarin? Yes, but it is highly improbable.
An incident involving a container marked "Sarin," but not actually
containing Sarin, is most likely and highly probable. A number of these
hoaxes already have occurred and will increase as more people realize the
impact they have.
Producing Nerve Agents
To make sarin you need di-isopropyl methylphosphonate and isopropyl
methylphosphonochloridate, chemicals that cannot be purchased legally in
the United States, but they can be made or imported illegally. The other
chemicals involved in the production of Sarin are tri-isopropyl phosphite;
phosgene combined with the di-isopropyl methylphosphonate generates
the isopropyl methylphosphonochloridate. Sodium fluoride also is
required, and if you see this in combination with any phosphonate, it
should be an indication that an illegal activity is going on. Although not
SM 3-32
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
used specifically in the process to make Sarin, sodium hydroxide is used
to decontaminate the glassware and personal protective equipment (PPE)
used in its manufacture. Other chemicals used include methylene
chloride, sodium fluoride, and water.
Another recipe for Sarin uses isopropyl alcohol, methyl phosphonic
dichloride, and methyl phosphonic difluoride. To make Soman, pinacolyl
alcohol is substituted for the isopropyl alcohol.
Chemicals Used in the Production of Sarin
Tri-isopropyl phosphite
Di-isopropyl methylphosphonate
Methylene chloride
Water
Methyl phosphonic dichloride
Phosgene
Isopropyl methylphosphonochloridate
Sodium fluoride
Isopropyl alcohol
Methyl phosphonic difluoride
Chemical Used in the Production of V-Series Agents
Triethyl phosphite
Methyl iodide
Methylthoxyphosphoryl chloride
Alkaline hydrosulfite solution
Anhydrous ethyl ether
Dimethylaminoethanethiol
Diethyl methyl phosphanate
Phosgene
2-dimethylaminoethanethiol
N, N, -dimethylethanolamine
Inerting gas
Triethylamine
Irritants (Incapacitating Agents)
There are four basic categories of irritants, or incapacitating agents as they
are called by the military. Many haz mat teams struggle with an unusual
odor complaint, typically the result of a mace or pepper spray release.
Prior to the development of the mace and pepper spray detector, it was
very difficult to determine the presence of these agents. The four irritants
and their military designations are
Military Designations of Irritants
Agent
Tear gas
Mace
Pepper spray
Combination mace/pepper
Military Designation
CR or CS
CN
OC
None designated
SM 3-33
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
Tear Gas
The procedure to make tear gas is fairly easy, but it does involve the use of
lab equipment, most of which can be purchased with relative ease.
Chemicals required to make tear gas are glycerine and sodium bisulfate.
The reaction used to make the tear gas is also easy. The Anarchist's
Cookbook suggests methods of dispersing the gas. It recommends placing
the gas under pressure in some type of container, one that is easily broken
when thrown.
To make mace, the Anarchist's Cookbook recommends using 10-percent
tear gas, a propellant such as sodium bicarbonate, and 20-percent
kerosene, which the book reports as the irritating agent in mace.
Other Toxic Gases
Carbon Monoxide
The text Silent Death provides detailed possible scenarios involving the
use of carbon monoxide, and how to set up a discharge system to avoid
detection. It also provides a recipe for making your own carbon
monoxide. The chemicals involved with the home production of carbon
monoxide are formic acid and sulfuric acid along with some simple lab
glassware.
Carbon Dioxide
Carbon dioxide is mentioned by Uncle Fester as one of the best of all
poisons. The mechanism of death probably would not be picked up by the
autopsy, and it usually appears that the victim merely died in his/her sleep.
For other responses, CO2 is a likely candidate during a sick-building
investigation. It does not take much CO2 to make a person develop
headaches and nausea. A slight elevation of CO2 in a building will cause
signs and symptoms to appear fairly quickly. Many haz mat teams should
place the detection of CO2 higher on their list of chemicals to sample for.
Arsine
The making of arsine involves the use of zinc powder, hydrochloric acid,
and arsenic trioxide.
SM 3-34
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Phosphine
The chemicals used to make phosphine gas are white phosphorus and
sodium hydroxide (or potassium hydroxide). Also used in the reaction is
nitrogen or carbon dioxide. After the reaction, there will be sodium
hypophosphite left over in a water bath, and the reaction also produces
diphosphine, which is extremely air reactive and has a tendency to ignite
when in contact with the air. Zinc phosphide also could be used, and if so,
hydrochloric acid will be used as a reducing agent.
EXPLOSIVES
Bombs appear to be the weapon of choice for terrorists. Approximately
70 percent of all terrorist incidents in the United States involve the use of
explosives. Improvised explosives can be designed by terrorists to deliver
harm and destruction and also can provide a vehicle for dispersal of
chemical, biological, incendiary, and nuclear agents.
Terminology
Explosives are defined as materials capable of violent decomposition.
This decomposition often takes the form of extremely rapid oxidation
(burning). Explosions result from the sudden and violent release of gas
during the decomposition of explosive substances. High temperature,
strong shock, and loud noise follow this release.
Explosives commonly are classified as high or low according to the speed
of their decomposition. When high explosives are initiated, the reaction is
propagated through the filler material at a speed at or above 3,300 feet per
second (fps). These explosives are designed to detonate and destroy a
target by a shattering effect. When low explosives are initiated, the
reaction is propagated through the filler material at a speed below 3,300
fps. These explosives are designed to deflagrate, or burn rapidly, and
destroy a target by a pushing and pulling effect.
After the initial positive pressure phase, a vacuum is created at the
explosion site. This creates a negative pressure that moves toward the
original center of the detonation at hurricane speed. It is less sudden, but
lasts approximately three times as long as the positive pressure wave.
Fragmentation occurs when the explosive device propels fragments at high
speed for long distances. This often accounts for many of the injuries or
casualties.
SM 3-35
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
Thermal effects sometimes are referred to as incendiary effects. Heat
produced by the detonation of either high or low explosives varies
according to the ingredient materials. High explosives generate greater
temperatures than low explosives, but the thermal effects from low
explosives last longer than those of high explosives.
The thermal effect is visible in the bright flash or fireball temporarily
produced by an explosion. Thermal effects vary with the type of
explosive, container, addition of fuels/accelerants, shielding, and
proximity. Fire and thermal effects are usually localized and short-lived
with conventional devices--those not enhanced for collateral incendiary
effects.
Improvised Explosive Devices (IED's) Commonly Used by
Terrorists
Vehicle bombs are usually large, powerful devices that consist of a
quantity of explosives fitted with a timed or remotely triggered detonator
packed into a car or truck. The two most famous vehicle bombings on
United States' soil were the World Trade Center bombing in New York
and the Alfred P. Murrah Federal Building bombing in Oklahoma City.
Pipe bombs are one of the most common explosive devices. They are at
the opposite end of the scale from vehicle bombs in terms of size and
destructive potential. Pipe bombs usually consist of a quantity of
explosives sealed into a length of metal or plastic pipe. A timing fuse
usually controls detonation. Other possible methods include electronic
timers, remote triggers, and motion sensors.
The satchel device is an old military term for an explosive device
consisting of a canvas overpack containing explosives. It is far more
powerful than a grenade, but can still be thrown. The container also may
be packed with antipersonnel materials such as nails and glass to inflict
more casualties. The Centennial Park explosives incident in Atlanta is an
example involving this type of device.
Other improvised explosive devices may be used, including homemade
grenades, mines, and/or projectiles. Explosive projectiles like rocketpropelled grenades (RPG's) have been used in the past but have not been a
common occurrence. In Fairfax County, Virginia, police confiscated
homemade projectiles capable of exploding on contact along with tubetype launchers from a private home after the individual who had
apparently manufactured the devices was found dead in the home. The
obvious danger associated with such weapons is the ability they afford the
terrorist to take the threat from a static to a dynamic environment. The
SM 3-36
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
possibility of driveby bombings certainly will increase the operational risk
to responders if they are included in the target scenario.
SUMMARY
Focusing on the use of chemical and physical properties of agents is
paramount to a successful response. As haz mat responders, we must use
the scientific facts to determine the level of risk, not hysteria or fiction.
Using the chemical and physical properties coupled with good detection
and monitoring techniques will allow the responder to maintain a high
level of safety. The key to survival is the use of vapor pressure, and
appropriate levels of protection based on this and the other properties of
the chemical. Using risk-based response, the responders can determine
incident severity, isolation distances, and appropriate levels of PPE.
SM 3-37
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
SM 3-38
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Activity 3.1
Ranking Hazardous Agents
Purpose
To provide you with insight into how the chemical and physical properties of agents
affect the hazards that they present.
Directions
1.
Work in small groups.
2.
Read through the five material safety data sheets (MSDS) provided in this
exercise.
3.
Rank the five agents from most to least hazardous to the responder.
4.
After ranking the chemicals, list what chemical and physical properties your
group used to rank the agents. Also, list any other considerations your group used
to make ranking decisions.
5.
A small amount has been spilled, for example, the equivalent of less than a gallon
of liquid. Conditions are 60F, cloudy, winds 3 mph, and 60 percent humidity.
6.
A spokesperson from your group will read your rankings and list of properties
considered to the rest of the class. Be prepared to explain your reasoning.
SM 3-39
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
Agent A
Description
Vapor Pressure
Volatility
Vapor Density
Specific Gravity
Melting Point
Ionization Potential
Boiling Point
Route of Entry
Effects
Symptoms
Reacts
Decomposes
Solubility
Protection
Detection Devices
Treatment
Decontamination
PEL
TLV
STEL
LD50
LC50
IDLH
LCt50
ICt50
SM 3-40
Greenish-yellow gas
5,000 mm/Hg
20,000,000 mg/m3
2.5
-67F
-33F
Respiratory
Immediate
Strong eye, throat and mucous membrane irritation,
coughing, choking, tightness in chest
With many substances, is a corrosive and an oxidizer
Slightly in water
Respiratory
pH, colorimetric tubes, Agent A electrochemical gas
sensor
Remove from environment, fresh air
Fresh air, flush with water if contaminated with liquid
0.5 ppm
0.5 ppm
1 ppm
10 ppm
~6500 ppm 1 min.
~600 ppm
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Agent B
Description
Vapor Pressure
Volatility
Vapor Density
Specific Gravity
Melting Point
Ionization Potential
Boiling Point
Route of Entry
Effects
Symptoms
Reacts
Decomposes
Solubility
Protection
Detection Devices
Treatment
Decontamination
PEL
TLV
STEL
LD50
LC50
IDLH
LCt50
ICt50
Brown liquid
2.9 mm/Hg @ 25C
20,000 mg/m3 @ 25C
5
1.07
-70F
<10.6 eV
310F
Respiratory, skin absorption
Immediate
Runny nose, tightness of the chest, gastrointestinal
symptoms will appear first
Stable
Quickly in acids and alkalis, slowly in water;
decomposes in 3 hours at 302F
Slightly in water, more in organic solvents
Respiratory and skin
Basic life support, decontamination
Fresh air, flush with water if contaminated with liquid
0.000017 ppm
9.3 mg/kg
0.03 ppm
12 ppm
8 ppm
SM 3-41
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
Agent C
Description
Vapor Pressure
Volatility
Vapor Density
Specific Gravity
Melting Point
Ionization Potential
Boiling Point
Route of Entry
Effects
Symptoms
Reacts
Decomposes
Solubility
Protection
Detection Devices
Treatment
Decontamination
PEL
TLV
STEL
LD50
LC50
IDLH
LCt50
ICt50
SM 3-42
Colorless liquid
760 mm/Hg @ 100C
22,933 mg/m3
1
1
34F
12.4 eV
100C or 212F
Ingestion, respiratory
Delayed
Convulsions, tremors, loss of muscle control
With many substances, can release hydrogen during a
reaction
Into hydrogen
In water
Respiratory
Remove from environment, fresh air
Fresh air, flush with water if contaminated with liquid
25 g/Kg
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Agent D
Description
Vapor Pressure
Volatility
Vapor Density
Specific Gravity
Melting Point
Ionization Potential
Boiling Point
Route of Entry
Effects
Symptoms
Reacts
Decomposes
Solubility
Protection
Detection Devices
Treatment
Decontamination
PEL
TLV
STEL
LD50
LC50
IDLH
LCt50
ICt50
Colorless to brown liquid
0.11 mm/Hg @ 25C
600 mg/m3
5.5
57F
<10.6 eV
423F
Skin
Delayed
Burning of skin
0.0005 ppm
0.0005 ppm
231 ppm
23 ppm
SM 3-43
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
Agent E
Description
Vapor Pressure
Volatility
Vapor Density
Specific Gravity
Melting Point
Ionization Potential
Boiling Point
Route of Entry
Effects
Symptoms
Reacts
Decomposes
Solubility
Protection
Detection Devices
Treatment
Decontamination
PEL
TLV
STEL
LD50
LC50
IDLH
LCt50
ICt50
SM 3-44
Colorless gas
1,180 mm/Hg
6,000,000 mg/m3
3
-288F
46F
Respiratory
Immediate for high levels, delayed for lower levels
Coughing, choking, tightness in chest
With water
Slightly in water
Slightly in water, soluble in benzene and acetic acid
Respiratory
Remove from environment, fresh air
Fresh air, flush with water if contaminated with liquid
0.1 ppm
0.1 ppm
2 ppm
800 ppm
400 ppm
UNIT 3: CHEMICAL AND PHYSICAL PROPERTIES
Ranking Agents
Most Dangerous
1.
2.
3.
4.
Least Dangerous
5.
Chemical and Physical Properties Considered
Other Factors Considered
Notes
SM 3-45
EMERGENCY RESPONSE TO TERRORISM: TACTICAL CONSIDERATIONS: HAZARDOUS
MATERIALS
SM 3-46