The mechanics of gassing

Among all those who make statements, speeches, or use sentences in which the expression “gas chamber” appears, how many actually know what they are talking about? It has not taken me very long to realise that many people commit one of the most glaring errors. These people imagine a “gas chamber” as being similar to a mere bedroom under the door of which a household gas is released. These people forget that an execution by gas is by definition profoundly different from a simple suicidal or accidental asphyxiation. In the case of an execution one must carefully avoid all risk of illness, poisoning or death for the executioner and his crew. Such a risk is to be avoided before, during and after the execution. The technical difficulties implied therein are considerable. I was most eager to know how domestic minks were gassed, how foxes were gassed in their dens and how, in the United States, a person condemned to death was executed by gassing. I found that, in the vast majority of cases, hydrocyanic acid was used for such purposes. This was precisely the same gas the Germans used to fumigate their barracks. It was also with this gas that they, allegedly, killed groups of individuals as well as great masses of people. I therefore studied this gas. I wanted to know its use in Germany and in France. I reviewed ministerial documents governing the use of this highly toxic substance. I had the good fortune of discovering certain documents on Zyklon B and hydrocyanic acid that had been gathered by the Allies in the German industrial archives at Nuremberg.

Then, with greater scrutiny, I re-examined certain statements and confessions that had been made in German and Allied courts concerning the use of Zyklon B for putting camp detainees to death, and I was shocked. And now, you in turn will also be shocked. I shall first offer you the statement or confession of Rudolf Höss. Then, I shall offer you the results of my research, purely physical, on hydrocyanic acid and Zyklon B. (Please bear in mind that Höss was one of the three successive commandants at Auschwitz, all three of whom were imprisoned and interrogated by the Allies. Only Höss left a confession, for which we are indebted to his Polish jailers.)

In that confession the description of the actual gassing is remarkably short and vague. However, it is essential to realise that all the others who claim to have been present at this sort of operation are also vague and brief and that their statements are full of contradictions on certain points. Rudolf Höss writes: “Half an hour after the release of the gas, the door would be opened and the fan turned on. The bodies immediately began to be removed.”[1] I call your attention to the word “immediately;” in German the word is sofort. Höss then adds that the crew in charge of handling and removing 2,000 bodies from the “gas chamber” and transporting them to the crematory ovens did so while “eating or smoking;” therefore, if I understand correctly, those tasks were all performed without gas masks. Such a description runs counter to all common sense. It implies that it is possible to enter an area saturated with hydrocyanic acid without taking any precautionary measures in the bare-handed lifting and hauling of 2,000 cyanided corpses that were still suffused with the lethal gas. The victims’ hair (which was supposedly clipped after the operation) was undoubtedly impregnated with the gas. Their mucous membranes would have been impregnated also. Air pockets between the bodies, supposedly heaped atop one another, would have been filled with the gas. What kind of super-powerful fan is able instantly to disperse so much gas drifting through the air and hidden in air pockets? Even if such a fan had existed, it would have been necessary to perform a test for the detection of any remaining hydrocyanic acid and to develop a procedure for informing the crew that the fan had actually fulfilled its function and that the room was safe. Now, it is abundantly clear from Höss’s description that the fan in question must have been endowed with magical powers in order to be able to disperse all of the gas with such flawless effect as to leave neither cause for concern nor need for verification of absence of the gas!

What mere common sense already suggested is now confirmed by the technical documents concerning Zyklon B and its use.[2] In order to fumigate a building the Germans were constrained by numerous precautionary requisites: trained teams, whose members were enrolled only after certification by a Zyklon B manufacturing plant; special equipment, amongst which, particularly, the “J” filters which, when used in gas masks, were capable of protecting the wearer in the most rigorous toxic conditions; evacuation of all surrounding buildings; warnings bearing the symbol of a skull and cross-bones posted in several languages; a meticulous examination of the site to be fumigated in order to locate and seal any fissures or openings therein; the sealing up of any chimneys or air shafts and the removal of keys from doors. The cans of Zyklon B were opened at the site itself. After the gas had apparently killed all the vermin, the most critical operation would begin: this was the ventilation of the site. Sentries were to be stationed at a certain distance from all doors and windows, their backs to the wind, in order to prevent anyone from approaching. The trained crew, in gas masks, would then enter the building and unseal the chimneys and cracks, and open the windows. This operation completed, they had to go outside, remove their masks and breathe freely for ten minutes. They then had to put the masks back on to re-enter the building and perform the next step. Once all this work was completed it was still necessary to wait twenty hours. Actually, because Zyklon B was “difficult to ventilate, because it adheres strongly to surfaces”, the dispersion of the gas required a long natural ventilation. This was especially important when large volumes of the gas were employed, as in the case of a building of more than one floor. (When Zyklon B was used in an autoclave with a total volume of only 10 cubic metres, ventilation, whether forced or artificial, was still necessary.) After twenty hours had elapsed the crew would return with their masks on. They would then verify, with a paper test (a sheet of paper turning blue in the presence of hydrocyanic acid), whether the site was indeed again fit for human habitation. And so we see that a site that had been gassed was not safely accessible until a minimum of 21 hours had elapsed. As for French legislation, it sets the minimum at 24 hours.[3]  

It becomes, therefore, apparent that in the absence of a magical fan capable of instantly expelling a gas that is “difficult to ventilate, because it adheres strongly to surfaces,” the “human slaughterhouse” called “gas chamber” would have been inaccessible for nearly a full day. Its walls, floors, ceiling would have retained portions of a gas that was highly poisonous to humans. And what about the bodies? Those bodies could have been nothing less than saturated with the gas, just as the cushions, mattresses and blankets discussed in the aforementioned technical documents on the use of Zyklon B would have been. Those mattresses etc. had to be taken outside to be aired and beaten for an hour, in dry conditions, and for two hours when the weather was humid. When this was finished, the items were then heaped together and beaten again if the paper test revealed any continued presence of hydrocyanic acid.

Hydrocyanic acid is both inflammable and explosive. How, then, could it have been used in close proximity to crematory ovens as is the case, for example, of the “gas chamber” in the “old Krema” of Auschwitz I? How could anyone have entered the “gas chamber” while smoking?

I have not yet even touched upon the subject of the superabundance of technical and physical impossibilities that become apparent upon an actual examination of the site and the dimensions of the supposed “gas chambers” at Auschwitz and Auschwitz-Birkenau. Moreover, just as an inquisitive fact-finder at the Auschwitz State museum may discover, those chambers were in reality nothing more than “cold storage rooms” (mortuaries), and were typical of such rooms in both layout and size. The supposed “gas chamber” of Krema II at Birkenau, of which only a ruin remains, was in fact a morgue, located below ground for protection from the summer heat, measuring 30 metres in length and 7 metres in width (two metres on either side for corpses and 3 metres down the centre to allow for the movement of wagons). The door, the passageways, the freight lift (which measured only 2.10 by 1.35 metres) that led to the crematory chamber were all of Lilliputian dimensions compared with the insinuations of Höss’s account.[4] According to Höss, the gas chamber could easily accommodate 2,000 standing victims, but had a capacity of 3,000. Can you imagine that? Three thousand people crammed into a space of 210 square metres. In other words, to make a comparison, 286 people standing in a room measuring 5 metres by 4 metres! Do not be fooled into believing that, before their retreat, the Germans blew up the “gas chambers” and crematory ovens so as to conceal any trace of their crimes. If one wishes to obliterate all trace of an installation that is intrinsically quite sophisticated, it must be scrupulously dismantled from top to bottom, in order for there to remain not a shred of incriminating evidence. Destruction by means of demolition would have been ingenuous. If explosives had been employed, mere removal of the concrete blocks would still have left such or such telltale sign. As a matter of fact, the Poles of the present day Auschwitz Museum have reconstructed the remains of some Kremas (meaning, in reality, reconstructions of crematoria and a supposed “gas chamber”). However, all the artifacts shown to tourists attest to the existence of crematory ovens rather than anything else.[5]  

In the USA the first execution by gassing took place on February 8, 1924 in the prison of Carson City, Nevada. Two hours after the execution, poison traces were still to be found in the prison courtyard. Mr Dickerson, governor of the prison, declared that, as concerned the condemned man, the method of execution was certainly the most humane thus far employed. But he added that he would reject that method in future because of the danger to the witnesses.[6]  

The real gas chambers, such as those created by the Americans in 1924 and further developed by them in 1936-1938, offer some idea of the inherent complexity of such a method of execution. The Americans, for one thing, only gas one prisoner at a time, normally (there exist some gas chambers, however, fitted with two seats for the execution of two brothers, for example). The prisoner is totally immobilised. He is poisoned by the hydrocyanic acid (actually, by means of sodium cyanide pellets dropped into a container of sulfuric acid and distilled water, resulting in the release of hydrocyanic acid gas). Within approximately 40 seconds, the prisoner dozes off, and in a few minutes he dies. Apparently, the gas causes no discomfort. As in the case of Zyklon B, it is the dispersion of the gas that causes problems. Natural ventilation for 24 hours is not possible in this case: obviously, the location of the site of execution precludes such ventilation as it would entail serious danger for the guards and inmates. What, then, is the best course of action with a gas posing such difficulties of ventilation? The solution is to transform the acidic vapours into a solid, a salt, which can then be flushed out with water. To this end vapours of ammonia, a base, are made to react with the acidic vapours, this chemical reaction forming the desired salt. When the hydrocyanic acid has all but vanished, a certain signal will alert the attending physician and his aides who are on the opposite side of a glass barrier. This signal is phenolphthalein. It is disposed in containers at various spots in the chamber: it turns from pink to purple in the absence of hydrocyanic acid. Once the absence of the poison is indicated and once an arrangement of ventilators draws the ammonia fumes out through an exhaust vent, the physician and his assistants enter the chamber wearing gas masks. They also wear rubber gloves for protection. The doctor ruffles through the dead convict’s hair so as to brush out any residual hydrocyanic acid. Only after a full hour has elapsed may a guard enter the chamber. The body is then washed very carefully and the room is hosed down. The ammonia gas has by this time been expelled via a high chimney stack above the prison. Because of the danger to guards normally stationed in the watchtowers, in some prisons these men are required to leave their post during an execution. I will just mention the other requisites for a completely air-tight gas chamber, such as the need for sealed locks, Herculite® glass barriers of considerable thickness (to resist implosion due to the partial vacuum inside the chamber), a vacuum system, mercury valves, etc.

A lethal gassing is no improvised act. If the Germans had decided to gas millions of people, a complete overhaul of some very formidable machinery would have been absolutely essential. A general order, instructions, studies, commands and plans would surely have been necessary also. Such items have never been found. Meetings of experts would have been necessary: architects, chemists, physicians, experts in a wide range of technical fields. Disbursements and allocations of funds would have been necessary. Had this occurred in a State such as the Third Reich, a wealth of evidence would surely have survived. We know, for example, down to the pfennig, the expenses for the kennel at Auschwitz and for the bay trees ordered for the nurseries. Orders for projects would have been issued. Auschwitz and Birkenau would not have been camps with so much coming and going allowed. In fact, it was because of all this to-ing and fro-ing, and in order to prevent any increase in escapes, that it was deemed necessary for registration numbers to be tattooed onto prisoners’ arms. Civilian workers and engineers would not have been permitted to mingle with the inmates. Passes would not have been granted to Germans in the camp, and their family members would not have had visiting rights. Above all, the prisoners who had served their sentences would not have been released and permitted to return to their respective countries: this well-guarded secret among historians was revealed to us several years ago in an article by Louis De Jong, Director of the NIOD (Netherlands Institute for War Documentation) in Amsterdam. Moreover, in the United States the recent publication of aerial photographs of Auschwitz deals the coup de grâce to the extermination fable: even in the summer of 1944, at the height of the influx of Hungarian Jews, there is, in those images, no indication of any bonfires of corpses within, or throngs of prisoners without, the Birkenau crematoria (but clearly visible are an open gate and a landscaped area), and there is no suspicious smoke (although the chimneys of the crematoria are said to have continuously spewed out smoke and flames visible from several kilometres away, day and night).

I shall conclude with a comment on what I regard as the criterion of false evidence regarding the gas chambers. I have noticed that all of these statements, vague and inconsistent as they are, concur on at least one point: the crew responsible for removing the bodies from the “gas chamber” entered the site either “immediately” or a “few moments” after the death of the victims. I contend that this point alone constitutes the cornerstone of the false evidence, because this is a physical impossibility. If you encounter a person who believes in the existence of the “gas chambers”, ask him how, in his opinion, the thousands of bodies were removed to make room for the next batch of victims.

March 21, 1980



[1] Kommandant in Auschwitz / Autobiographische Aufzeichnungen (Commandant of Auschwitz / Autobiographical Notes) by Rudolf Höss, introduction and commentary by Martin Broszat, 1958, Verlagsanstalt, Stuttgart. It is on page 166 of this book, in the part of the confession that Höss had drawn up in November 1946, that the following passage is found: “Eine halbe Stunde nach den Einwurf des Gasses wurde die Tür geöffnet und die Entlüftungsanlage eingeschaltet. Es wurde sofort mit dem Herausziehen der Leichen begonnen.” (“Half an hour after the gas had been thrown in, the door was opened and the ventilating apparatus switched on. The removal of the bodies was begun immediately.”) And it is on page 126, in the fragment dated February 1947, that it is said that the squad in charge of removing the corpses from the “gas chambers” did this job “mit einer stumpfer Gleichmütigkeit” (“with a gloomy indifference”) as though it were an everyday chore (“als wenn es irgend etwas Alltäglisches wäre“). Höss is supposed to have added: “Beim Leichenschleppen assen sie oder rauchten,” that is to say: “While pulling out [the corpses] they used to eat or smoke.” For Höss, moreover, they did not stop eating. They would eat when pulling the bodies out of the chambers, when extracting their gold teeth, when cutting off their hair, when dragging them towards the furnaces or pits. Höss even adds this outrageous remark: “At the pits they used to keep the fire going. They would pour accumulated molten fat over the new bodies, and they would poke around in the mounds of burning bodies to create a flue.” 

Höss did not reveal how the fat managed not to be burnt itself (corpses are not roasted as if they were chickens but are burnt in heaps on the ground or on pyres). He does not tell us how the men could approach these formidable pyres to collect the streams of fat (!), neither does he tell us how they could get close enough to poke around in those mounds of bodies to effect a flue. The absurdity of this “pouring accumulated fat” (“das Übergiessen des angesammelten Fettes“) is, furthermore, so obvious that the French translator of the book presented by Martin Broszat quite discreetly omitted to translate those five German words (Rudolf Höss, Le Commandant d’Auschwitz parle (The Commandant of Auschwitz Speaks), translated from German into French by Constantin de Grunwald, Julliard, Paris 1959, printing of March 15, 1970, p. 212. Filip Müller has written a book entitled Sonderbehandlung, translated as Eyewitness Auschwitz / Three Years in the Gas Chambers, Stein & Day, New York 1979, XIV-180 p. From page 132 to 142 he accumulates the most astonishing stories about boiling human fat running like water, collecting pans for the fat, sizzling fat scooped out with buckets on a long curved rod and poured all over the pit, the SS guard Moll flinging live babies into the boiling human fat, and so on.

[2] For their various trials generally called “Nuremberg Trials”, the Americans perused many technical documents concerning Zyklon B. If they had read these documents carefully, and if they had – as I myself have done – continued further research in certain technical tomes in the Library of Congress in Washington, they would have become aware of the incredible number of technical impossibilities contained in the German “gas chamber” evidence. One day I shall devote a study to four specific documents that, in my opinion, completely destroy the legend of the “gas chambers.” Those four documents are: first, two documents recorded by the Americans for the Nuremberg Trials, and then, two technical studies signed by Gerhard Peters, all of which one may consult at the Library of Congress. I shall remind the reader that Gerhard Peters was, during the war, acting director of the firm DEGESCH (Deutsche Gesellschaft fur Schädlingsbekämpfung: “German Company for Pest Control”) which managed, in particular, the distribution of Zyklon B. After the war Peters was to be brought before the courts many times by his own compatriots. He stated that he had never during the war heard about any homicidal use of Zyklon B. 

Nuremberg documents (documents with the prefix NI, standing for “Nuremberg, Industrialists”):

  1. NI-9098, recorded only on July 25, 1947: a brochure entitled Acht Vorträge aus dem Arbeitgebiet der DEGESCH (Eight lectures on aspects of DEGESCH’s Field of Operation) and printed in 1942 for private use. At the end of this brochure, page 47, there appears a descriptive table on each of the eight gases distributed by the firm. At point number 7 of the description one reads for Zyklon B: “Lüftbarkeit: wegen starken Haftvermögens des Gases an Oberflächen erschwert und langwierig.” (“Ventilation Properties: complicated and long to ventilate since the gas adheres strongly to surfaces.”)
  2. NI-9912, recorded only on August 21, 1947: a public notice entitled Richtlinien fur die Anwendung von Blausäure (Zyklon) zur Ungeziefervertilgung (Entwesung) (Directives for the use of Prussic Acid (Zyklon) for the Destruction of Vermin (Disinfestation)). This document is of capital importance. Better than any other it shows to what degree the handling of Zyklon B can be done only by trained personnel. The time required for the product to destroy vermin ranges from 6 hours in hot weather to 32 hours in cold. The normal duration is 16 hours. This long duration is explained undoubtedly by the composition of Zyklon. Zyklon is prussic acid, or hydrocyanic acid, absorbed by a support substance of diatomite. The gas is released slowly because of the nature of its support. This slowness is such that one cannot understand how on earth the Germans could have chosen a gas such as Zyklon in order to liquidate masses of human beings. It would have been easier for them to have used hydrocyanic acid in its liquid form. They had at their disposal significant quantities of this acid in the laboratories of the IG-Farben plant at Auschwitz, where they tried to make synthetic rubber. It is from document NI-9912 that I draw the information concerning the use of Zyklon B for the fumigation of a barracks, the length of time of its airing out (at least 21 hours), etc.

Documents at the Library of Congress. These concern two technical studies written by Gerhard Peters, both published in Sammlung Chemischer & Chemisch-technischer Vorträge, the first in 1933 in Neue Folge, Heft 20, and the other in Neue Folge, Heft 47a in 1942 (review published by Ferdinand Enke at Stuttgart). Here are the titles, followed by the Library of Congress references:

  1. “Blausäure zur Schädlingsbekämpfung” (QD1, S2, n.f., hft. 20, 1933), 75 p.
  2. “Die hochwirksamen Gase und Dämpfe in der Schädlingsbekämpfung” (QD1, S2, n.f., hft. 47a, 1942), 143 p. It should be said in passing that it is admirable that this review that was published during the war in Germany should have arrived safely even during the war at the Library of Congress in Washington! The 1942 issue bears the Washington registration date of… April 1, 1944!

[3] French regulations concerning the use of hydrocyanic acid are as strict as the German. See decree 50-1290 of October 18, 1950 of the Ministry of public health, Paris.

[4] The plan that enables us to give these dimensions to the nearest centimetre is found in the archives of the State Museum of Oswiecim (Auschwitz): the reference number of its reproduction is Neg. 519. The plans of “Kremas” (crematoria) IV and V are even more interesting than those of Kremas II and III. They prove, in effect, that the three places deceitfully described as “gas chambers” were in fact inoffensive structures, complete with ordinary doors and windows. The sole means for the SS men to “throw the Zyklon” into these places “from the outside” would have been as in the following scenario: they would have had to ask their victims – crammed within by the hundreds or thousands – to open the windows to allow them to “throw in the Zyklon”, after which action the victims would have carefully closed the windows, then refrained from smashing the windowpanes, until death ensued. It is perfectly easy to understand why the Polish Communist authorities are so reluctant to display these plans; they prefer to rely on the Höss “confessions” with no supporting topographical data.

[5] These interesting remains of the crematoria can be seen through a large glass pane in the rear room which, in exhibition block No. 4, is devoted to the Kremas.

[6] These details of the first execution by poison gas were published in the Belgian daily Le Soir of February 9, 1974, under the heading “Il y a 50 ans” (50 years ago): a reprint of an article from its February 9, 1924 edition.


This article first appeared, without the six notes of reference and explanation, in the Journal of Historical Review, vol. 1, no. 1 (spring 1980), p. 23-30.