Systemic asphyxiant chemical-warfare agents

[Dorothey Allen]

There are many types of chemical-warfare agents that affect different parts of the body. Systemic asphyxiants poison cells throughout the body and include

Cyanide compounds
Hydrogen sulfide

Systemic asphyxiants have also been called blood agents because they are distributed through the blood. However, they damage cells throughout the body, not just blood cells.
Cyanide compounds include hydrogen cyanide and cyanogen chloride, which are highly volatile liquids or gases at room temperature. The combustion of many household and industrial chemicals can produce cyanides, and people suffering from smoke inhalation from any kind of industrial or household fire may also have cyanide poisoning. Although cyanide has a characteristic odor of bitter almonds, about half of people lack the ability to detect it.
Hydrogen sulfide is always a gas at room temperature, so exposure to it is usually by inhalation. Hydrogen sulfide can be produced by mixing sulfur-containing household chemicals with acids. Residual gas can affect rescuers, causing many additional casualties. Hydrogen sulfide is also produced when manure decomposes. Large farm manure pits often contain lethal quantities of the gas. Hydrogen sulfide has a characteristic rotten egg odor, but high concentrations damage a person

[Sarah]

Systemic asphyxiants are a type of chemical-warfare agent and include

Cyanide compounds
Hydrogen sulfide

Systemic asphyxiants have also been called blood agents because they are systemically distributed via the blood. However, their site of action is not the blood but rather at the cellular level throughout the body.
Cyanide salts have been used to murder via ingestion, but mass casualties could also result from inhalation of hydrogen cyanide or cyanogen chloride, which are highly volatile liquids or gases at ambient temperatures. Cyanides are also products of combustion of numerous household and industrial contents, and patients with smoke inhalation may also have cyanide poisoning. Cyanide has a characteristic bitter-almond odor, but ability to detect this odor is conferred by a single gene that is absent in half the population.
Hydrogen sulfide is always a gas at ambient temperatures. Exposure is thus usually by inhalation. Hydrogen sulfide can be produced by mixing sulfur-containing household chemicals with acids; this combination has been used for suicide (termed detergent suicide), and residual gas can affect rescuers, causing multiple casualties. Hydrogen sulfide is also produced when manure decomposes. Large farm manure pits often contain lethal quantities of the gas, which may cause multiple casualties as would-be rescuers without proper protective gear succumb. Hydrogen sulfide has a characteristic rotten egg odor, but high concentrations damage olfactory fibers so that this odor will not be perceived in the most lethal environments.
(See also Overview of Chemical-Warfare Agents.)