Evaporation Characteristics of Zyklon

Zyklon B does not release its poison gas instantaneously, but rather over an extended period of time. Since this period of time can be decisive for the evaluation both of eyewitness accounts as well as of chemical analyses, it will be investigated more thoroughly in this chapter. 

Irmscher of DEGESCH reported in a paper written in 1942 that, at that time, the use of cardboard discs and gypsum (Ercco) were the most commonly used carrier material.427 The gypsum version was 

426 Assuming a volume of 10 m3 in the chamber, 75 Liter HCN corresponds to 0.75% by volume, i.e., somewhat more than double the end values taken by Leuchter. 

Irmscher, Nochmals Die Einsatzfahigkeit der Blausaure bei tiefen Temperaturen Zeitschriftfur hygienische Zoologie und Schadlingsbekampfung, 1942, pp. 35f. on the history of the development of Zyklon B, see Wolfgang Lambrecht, Zyklon B—eine Erganzung , 

The evaporation characteristics of this product at various temperatures, low relative humidity of the air, and a fine distribution of the carrier material are reproduced in Graph 9 as given by Irmscher. 

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