This article is from the Holocaust FAQ, by Ken McVay email@example.com with numerous contributions by others.
Holocaust denial often claims that if the Nazis had intended to kill
people by lethal gassing, they would have used something other than
Zyklon-B was in use at Auschwitz as a delousing agent, and was thus
readily available. The Nazis had experience in its safe use as well,
which made it even more attractive.
In addition, Zyklon B was easy to ship and to store, which also
made it attractive to the SS, who ordered enough of it, as Ho"ss
pointed out in his testimony, to kill two million people.
Yitzhak Arad mentions Christian Wirth's rejection of Zyklon-B
for use in exterminations: Wirth developed his own ideas on the
basis of the experiences he had gained in the Euthanasia
program. Thus, in Belzec he decided to supply the fixed gas
chamber with gas produced by the internal-combustion engine of a
motorcar. [He] rejected Cyanide B which was later used at
Auschwitz. This gas was produced by private firms and its
extensive use in Belzec might have aroused suspicion and led to
problems of supply. He therefore preferred a system of
extermination based on ordinary, universally available gasoline
and diesel fuel. (YVS XVI, 211)
In a letter requesting for a truck to bring Zyklon-B to Auschwitz,
the standard camouflage term "resettlement of Jews" is used to refer
to extermination. Another such document asks for "material for
special treatment" - another term used to disguise extermination
(Get ~/gifs/resett.gif; also Pressac, 557. For more examples of
the camouflage terms noted, see file of original Nazi documents).
Radio message 13 SS Garrison Radio Station Auschwitz Origin WVHA
[SS economic administration head office]
Received 2nd October 1942 in the Kommandantur of Auschwitz
The movement authorization for one 5 Ton truck with trailer to
Dessau and back in order to pick up material for the
resettlement of the Jews, is hereby accorded.
The authorization is to be given to the driver.
SS Lieutenant Colonel
Permanent representative of the head
of the service with the rank of Waffen SS
Head of the radio station
When camp adjutant R. Mulka was asked by Judge Hofmeyer what
"material for the resettlement of the Jews" meant, he answered "well,
sure. Zyklon-B" (The Auschwitz trial in Frankfurt, 11 Sep. 1964).