Zyklon B was the substance used by the
Nazis to exterminate prisoners in the
gas chambers.
It was manufactured, under the orders of the Nazi government, by the Flick Manufacturing Corporation. At the Nuremburg Trials the company were found guilty, the tribunal cited that that making a criminal weapon cannot be distinguished from using it.
(Perhaps this was how the character of 'Herr Flick' was named as such in 'Allo 'Allo?)
The use of Zyklon B came about through, more or less, trial and error. Earlier gassing techniques were attempted using the exhaust fumes from lorries, but these were found to be inefficient, so alternative methods were sought. The gas cannisters would be placed in a gap in the chamber walls, then pierced. The gas would then enter the chambers through shower heads, killing all within. The people who had to put the canisters would also die, thusly, this task was handed to the Jews.
Zyklon B was invented at the Kaiser Wilhelm Institute for Physical Chemistry in Berlin. Phosgene, Mustard Gas and Sarin were also invented there. It was originally a fumigant and rodenticide. It was used mostly to rid ships and builings of rats and mice. One of the main reasons it was used to exterminate Jews was because of its wide availability as a seemingly innocent pesticide. It killed by restricting or cutting off the supply of oxygen to the bloodstream.
Zyklon B is created by combining hydrocyanic acid with a porous carrier substance like wood pulp, or absorbant clay. This combination would usually be formed into pellets then sealed in canisters until they were ready for use.
SPECIFICATIONS FOR HCN
Name: HCN, hydrocyanic acid; prussic acid
Boiling point: 25.7 C / 78.3 F at 760 mm Hg
Specific gravity: 0.69 at 18 C / 64 F
Vapor density: 0.947 (air = 1)
Melting point: -13.2 C / 8.2 F
Vapor pressure: 750 mm Hg at 25 C / 77 F 1200 mm Hg at 38 C /100F
Solubility in water: 100%
Appearance: clear
Color: slightly bluish
Odor: bitter almond, very mild, non-irritating (odor is not considered a safe method of determining presence of the poison)
Hazards:
1. Unstable with heat, alkaline materials and water
2. Will explode if mixed with 20% sulfuric acid.
3. Polymerization (decomposition) will occur violently, with heat, alkaline material or water. Once started, reaction is autocatalytic and uncontrollable. Will explode.
4. Flash point: -18 C / 0 F
5. Autoignition temperature: 538 C / 1000 F
6. Flammable limits in air volume % lower 6 upper 41
info from various sources and www2 analysis sites.