Blood agent
Encyclopedia
A blood agent is a toxic chemical agent that affects the body by being absorbed into the blood. They are fast-acting, potentially lethal poisons that typically manifest at room temperature as volatile colorless gases with a faint odor. Blood agents are either cyanide
- or arsenic
-based.
or ingestion
. As chemical weapons, blood agents are typically disseminated as aerosol
s and take effect through inhalation. Due to their volatility
, they are more toxic in confined areas than in open areas.
Cyanide
compounds occur in small amounts in the natural environment and in cigarette smoke. They are also used in several industrial processes and as pesticides. Cyanides are released when synthetic fabric
s or polyurethane
burn, and may thus contribute to fire-related deaths. Arsine
gas, formed when arsenic
encounters an acid, is used as a pesticide and in the semiconductor industry; most exposures to it occur accidentally in the workplace.
Cyanide-based blood agents irritate the eyes and the respiratory tract
, while arsine is nonirritating. Hydrogen cyanide has a faint, bitter, almond odor that only about half of all people can smell. Arsine has a very faint garlic odor detectable only at greater than fatal concentrations.
Exposure to small amounts of cyanide has no effect. Higher concentrations cause dizziness, weakness and nausea, which cease with the exposure, but long-time exposure can cause mild symptoms followed by permanent brain damage and muscle paralysis. Moderate exposure causes stronger and longer-lasting symptoms, including headache, that can be followed by convulsions and coma. Stronger or longer exposure will also lead to convulsions and coma. Very strong exposure causes severe toxic effects within seconds, and rapid death.
The blood of people killed by blood agents is bright red, because the agents inhibit the use of the oxygen in it by the body's cells. Cyanide poisoning can be detected by the presence of thiocyanate
or cyanide in the blood, a smell of bitter almonds, or respiratory tract inflammations and congestions in the case of cyanogen chloride
poisoning. There is no specific test for arsine poisoning, but it may leave a garlic smell on the victim's breath.
is usually respiratory failure
.
Blood agents work at the cellular level
by preventing the exchange of oxygen
and carbon dioxide
between the blood and the body's cells. This causes the cells to suffocate from lack of oxygen. Cyanide-based agents do so by interrupting the electron transport chain
in the inner membranes of mitochondria. Arsine damages the red blood cell
s which deliver oxygen throughout the body.
Due to their high volatility, cyanide agents generally need no decontamination. In enclosed areas, fire extinguishers spraying sodium carbonate
can decontaminate hydrogen cyanide, but the resulting metal salts remain poisonous on contact. Liquid hydrogen cyanide can be flushed with water.
Cyanide poisoning can be treated with antidotes; see the corresponding article.
Sodium cyanide
and potassium cyanide
, colorless crystalline compounds similar in appearance to sugar, also act as blood agents. Carbon monoxide
could technically be called a blood agent because it binds with oxygen-carrying hemoglobin in the blood (see carbon monoxide poisoning
), but its high volatility makes it impractical as a chemical warfare agent.
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
- or arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
-based.
Exposure
Blood agents work through inhalationInhalation
Inhalation is the movement of air from the external environment, through the air ways, and into the alveoli....
or ingestion
Ingestion
Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in the substance through the mouth into the gastrointestinal tract, such as through eating or drinking...
. As chemical weapons, blood agents are typically disseminated as aerosol
Aerosol
Technically, an aerosol is a suspension of fine solid particles or liquid droplets in a gas. Examples are clouds, and air pollution such as smog and smoke. In general conversation, aerosol usually refers to an aerosol spray can or the output of such a can...
s and take effect through inhalation. Due to their volatility
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...
, they are more toxic in confined areas than in open areas.
Cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
compounds occur in small amounts in the natural environment and in cigarette smoke. They are also used in several industrial processes and as pesticides. Cyanides are released when synthetic fabric
Synthetic fabric
Synthetic fabrics are textiles made from synthetic fibers. They are used primarily to make clothing. A synthetic fabric is plastic fabric. It is also used to cover skin of androids so it looks human like. Some of the examples of synthetic clothings were usually made of polyester, acrylic, and nylon....
s or polyurethane
Polyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
burn, and may thus contribute to fire-related deaths. Arsine
Arsine
Arsine is the chemical compound with the formula AsH3. This flammable, pyrophoric, and highly toxic gas is one of the simplest compounds of arsenic...
gas, formed when arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
encounters an acid, is used as a pesticide and in the semiconductor industry; most exposures to it occur accidentally in the workplace.
Symptoms
The symptoms of blood agent poisoning depend on concentration and duration.Cyanide-based blood agents irritate the eyes and the respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
, while arsine is nonirritating. Hydrogen cyanide has a faint, bitter, almond odor that only about half of all people can smell. Arsine has a very faint garlic odor detectable only at greater than fatal concentrations.
Exposure to small amounts of cyanide has no effect. Higher concentrations cause dizziness, weakness and nausea, which cease with the exposure, but long-time exposure can cause mild symptoms followed by permanent brain damage and muscle paralysis. Moderate exposure causes stronger and longer-lasting symptoms, including headache, that can be followed by convulsions and coma. Stronger or longer exposure will also lead to convulsions and coma. Very strong exposure causes severe toxic effects within seconds, and rapid death.
The blood of people killed by blood agents is bright red, because the agents inhibit the use of the oxygen in it by the body's cells. Cyanide poisoning can be detected by the presence of thiocyanate
Thiocyanate
Thiocyanate is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts potassium thiocyanate and sodium thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates...
or cyanide in the blood, a smell of bitter almonds, or respiratory tract inflammations and congestions in the case of cyanogen chloride
Cyanogen chloride
Cyanogen chloride is an inorganic compound with the formula NCCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and...
poisoning. There is no specific test for arsine poisoning, but it may leave a garlic smell on the victim's breath.
Effects
At sufficient concentrations, blood agents can quickly saturate the blood and cause death in a matter of minutes or seconds. They cause powerful gasping for breath, violent convulsions and a painful death that can take several minutes. The immediate cause of deathCause of Death
Cause of Death is a 1990 album by American death metal band Obituary. Cause of Death is considered a classic album in the history of death metal. The artwork was done by artist Michael Whelan...
is usually respiratory failure
Respiratory failure
The term respiratory failure, in medicine, is used to describe inadequate gas exchange by the respiratory system, with the result that arterial oxygen and/or carbon dioxide levels cannot be maintained within their normal ranges. A drop in blood oxygenation is known as hypoxemia; a rise in arterial...
.
Blood agents work at the cellular level
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
by preventing the exchange of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
between the blood and the body's cells. This causes the cells to suffocate from lack of oxygen. Cyanide-based agents do so by interrupting the electron transport chain
Electron transport chain
An electron transport chain couples electron transfer between an electron donor and an electron acceptor with the transfer of H+ ions across a membrane. The resulting electrochemical proton gradient is used to generate chemical energy in the form of adenosine triphosphate...
in the inner membranes of mitochondria. Arsine damages the red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...
s which deliver oxygen throughout the body.
Detection and countermeasures
Chemical detection methods, in the form of kits or testing strips, exist for hydrogen cyanide. Ordinary clothing provides some protection, but proper protective clothing and masks are recommended. Mask filters containing only charcoal are ineffective, and effective filters are quickly saturated.Due to their high volatility, cyanide agents generally need no decontamination. In enclosed areas, fire extinguishers spraying sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...
can decontaminate hydrogen cyanide, but the resulting metal salts remain poisonous on contact. Liquid hydrogen cyanide can be flushed with water.
Cyanide poisoning can be treated with antidotes; see the corresponding article.
List of blood agents
The information in the following table, which lists blood agents of military significance, is taken from Ledgard. The values given are on a scale from 1 to 10.| Agent | Description | Melting / boiling point | Effectiveness as blood agent | Persistence, open area | Persistence, enclosed area | Field stability | Storage stability | Toxicity as blood agent |
|---|---|---|---|---|---|---|---|---|
| Hydrogen cyanide | Colorless gas or liquid, almond odor, burns with a bluish flame. | -13 / 26 °C | 10 | 2 | 9 | 10 | 8 | 10 |
| Cyanogen Cyanogen Cyanogen is the chemical compound with the formula 2. It is a colorless, toxic gas with a pungent odor.The molecule is a pseudohalogen. Cyanogen molecules consist of two CN groups — analogous to diatomic halogen molecules, such as Cl2, but far less oxidizing... |
Colorless gas, almond odor, burns with a pinkish flame having a blue border. | -28 / -21 °C | 9 | 2 | 9 | 8 | 7 | 9 |
| Cyanogen chloride Cyanogen chloride Cyanogen chloride is an inorganic compound with the formula NCCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and... |
Colorless gas or liquid, pungent and biting odor, soluble in water and alcohol. | -6 / 14 °C | 8 | 3 | 9 | 9 | 9 | 8 |
| Cyanogen bromide Cyanogen bromide Cyanogen bromide is a pseudohalogen compound with the formula CNBr. It is a colorless solid that is widely used to modify biopolymers, fragment proteins and peptides, and synthesize other compounds.-Synthesis, basic properties, and structure:... |
Colorless needle-shaped or cubic crystals, tending to volatize on standing, hence of limited usefulness as a weapon. | 52 / 62 °C | 9 | 5 | 8 | 5 | 6 | 8 |
| Arsine Arsine Arsine is the chemical compound with the formula AsH3. This flammable, pyrophoric, and highly toxic gas is one of the simplest compounds of arsenic... |
Colorless gas, garlic-like odor, slightly soluble in water. | -117 / -62 °C | 9 | 3 | 8 | 5 | 9 | 9 |
| Vinyl arsine | Colorless liquid, irritating and bitter odor, slightly soluble in water, also acts as a blister agent Blister agent A blister agent, or vesicant, is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affected... . |
124 °C (boiling) | 7 | 7 | 9 | 8 | 9 | 6 |
| Phosgene Phosgene Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles... |
Colorless gas and slightly yellow liquid, moldy hay odor, slightly soluble in water and soluble in most solvents, also acts as a choking agent. | -118 / 8 | 10 | 6 | 9 | 5 | 8 | 6 |
Sodium cyanide
Sodium cyanide
Sodium cyanide is an inorganic compound with the formula NaCN. This highly toxic colorless salt is used mainly in gold mining but has other niche applications...
and potassium cyanide
Potassium cyanide
Potassium cyanide is an inorganic compound with the formula KCN. This colorless crystalline compound, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewelry for chemical gilding and...
, colorless crystalline compounds similar in appearance to sugar, also act as blood agents. Carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
could technically be called a blood agent because it binds with oxygen-carrying hemoglobin in the blood (see carbon monoxide poisoning
Carbon monoxide poisoning
Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide . Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect...
), but its high volatility makes it impractical as a chemical warfare agent.