The "Gas Testers" of Auschwitz

Testing for Zyklon B Gas Residues · Documents – Missed and Misunderstood
Published: 1998-01-01

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In 1989, Prof. Faurisson's challenge[1] to offer him one single tangible proof for the existence of National Socialist homicidal gas chambers – beyond untrustworthy 'eyewitness' testimonies – resulted in an emphatic response by French scholar Jean-Claude Pressac. In a massive work he presented "39 criminal traces" for the existence of homicidal gas chambers.[2] All of these traces are to be found in German wartime documents, most of them including the word "gas" in one way or another, but never explicitly mentioning the use of gas for murder. Thus, it was easy for revisionists to refute Pressac's alleged criminal traces by pointing out perfectly harmless meanings of the word "gas" in the context of each of those documents, for example as gas to kill lice or in the context of gas warfare.[3]

In another book published four years later, however, Pressac presented another, previously unknown document.[4] Pressac claimed that this document, written by the company Topf & Söhne (see ill. 1.), was an acknowledgement of a telegram[5] which the Central Construction Office of the Auschwitz camp had sent to this firm a few days earlier (see ill. 2).

Even those two documents do not have any content that would put the word "gas" into a homicidal context. The Topf letter, however, does undermine the so far highly plausible revisionist explanation of the meaning of the aforesaid telegram, which refers to "10 gas testers" (10 Gasprüfer). As W. Rademacher[6] and C. Mattogno[7] demonstrated as early as 1994, this term is used for smoke gas analyzers, as they are installed in smoke flues and chimneys of various firing installations (crematories, heaters, etc.). Both the number of testers ordered (10 devices for 10 smoke flues in the Crematories II & III of Auschwitz-Birkenau) as well as the company which was asked to supply them (Topf & Söhne constructed crematory ovens) support this thesis.

However, the confirmation letter of the Topf firm, as published by Pressac in 1993, suddenly mentions "display devices for hydrocyanic acid residues" (Anzeigegeräten für Blausäure-Reste), a new word creation suggesting a context with "gas residue detection devices for Zyklon" (Gasrestnachweisgeräten für Zyklon) – the proper term – which were available in those years. If this document were genuine, it would indicate that the Central Construction Office of Auschwitz ordered devices with which it intended to detect hydrocyanic acid residues in Crematories II & III, which are claimed to have housed in their basement the two homicidal gas chambers most frequently used. However, this still would not prove that such residues of hydrocyanic acid would have stemmed from homicidal gassings.

Prof. Butz suggested that the waste incinerator installed in Crematory II could be seen as a potential source of hydrocyanic acid, and thus as the reason to order such detection devices.[8] Without going into detail, reference is made here also to a response to Butz' paper by C. Mattogno, in which he emphasized the weak nature of Butz' thesis.[9] Doubts about the authenticity of Pressac's latest documentary discovery had been raised as early as 1994.[6],[7] In addition to the arguments listed there, I would like to point out a stylistic oddity of this letter, which, if  isolated, does not indicate a forgery, but which supports a skeptical attitude regarding the authenticity of this document:

The wording "kommen wir Ihnen sofort näher" (we shall get close to you immediately) is utter nonsense, because such a wording would refer to the physical approach of two bodies. The proper rendering would be "kommen wir sofort auf Sie zu" (we will approach you immediately).

In the first section of the two-part paper following, C. Mattogno summarizes the discussion of these two documents, whose significance cannot be underestimated, because it has been presented as a key document to prove the existence of homicidal gas chambers in Auschwitz by orthodox historians and by the media since the document's first publication in 1993/1994.[10]

The second section puts the whole discussion into a proper context of the technology used during the war to detect hydrocyanic acid residues in the atmosphere of disinfestation (delousing) rooms, and to protect individuals working in such rooms from any harm.

Germar Rudolf

1. Jean-Claude Pressac's Interpretation

The examination of a document can lead to correct historical conclusions only after it has been placed not merely within its general historical context, but also within its bureaucratic context as well as within the context of what is technically possible. Insufficient knowledge of context or erroneous contextualization inevitably leads to distortions of the actual meaning of a document and to misunderstandings regarding the problems involved.

An example of such a methodic deficiency is that of Jean-Claude Pressac in his misinterpretation of two documents relating to "gas testers" in Auschwitz. In his book Die Krematorien von Auschwitz Pressac writes:[11]

"As soon as Messing's construction work had progressed far enough, the contractor sent a telegram to Topf on February 26 asking for immediate shipment of ten gas testers for construction site 30 (Crematory II). The SS wanted to determine whether the new ventilation system of Morgue I, which was originally installed for mortuary purposes (meaning a high air intake power and a low air exhaust power) would be sufficient, because for usage as a gas chamber, this installation had to be in reverse order, that is, a low air intake power and a high air exhaust power."

Before continuing, it should be pointed out, both in fairness to Pressac and to clarify his line of reasoning, that the ambiguous words I have emphasized are the result of serious misunderstanding by the two German translators of the original French text; Pressac is actually referring to "upper aeration and lower de-aeration" and vice versa[12] in the sense of aeration or de-aeration from the top or bottom of the premises. I shall return to this point. Pressac goes on to say:[13]

Ill. 1: Telegram by the Central Construction Office Auschwitz to the firm Topf & Söhne, Feb. 26, 1943: Archivum Panstwowego Muzeum W Oswiecimiu, BW 30/34, p. 48. Translation:

"[...] Send off immediately 10 gas detectors as discussed. Hand in estimate later'. [...]

"Sander and Prüfer sent the following response on March 2:

Erfurt, March 2, 43

Regarding: Crematory [II]
gas testers

We confirm the receipt of your telegram, saying:

'Send off immediately 10 gas detectors as discussed. Hand in estimate later'.

In this regard, we let you know that already two weeks ago we asked 5 different firms about the indicators of hydrogen cyanide residue requested by you. We received negative answers from 3 firms, and from two others an answer is still outstanding.

In case we receive notification in this matter, we shall get close to you immediately so that you can get in contact with the firm producing these devices.

H a i l   H i t l e r !
J.A. Topf & Söhne
per prokura

The Construction Office received the letter on 05 March. This document clearly proves the presence of a gas chamber in Crematory II."

It is important to emphasize that, in his original text, Pressac refers explicitly to a "homicidal gas chamber"[14] and that in his first work, Pressac, who had already interpreted the term "gas testers" as "gas detectors" for hydrocyanic acid, raises a very important question in this regard:[15]

"Since Topf's production consisted essentially of brewery equipment (cauldrons vats, etc), metal conduits and containers (ventilation, ducting, grain silos, etc), together with the associated components (fans, valves, and cocks) and, of course, incineration furnaces, they did not manufacture gas detectors, objects associated with systems totally foreign to their spheres of activity, so they must necessarily have had to order them from another civilian firm. Why did the SS use Topf as an intermediary instead of directly approaching a specialist supplier?

The answer must be that in this way they avoided awkward questions and conclusions that might have occurred if some civilian firm not knowing the 'special activity' of the Auschwitz camp had received such an order. On the other hand, there were no such worries in dealing with Prüfer, who was after all technical advisor for the Krematorien."

According to Pressac, the outcome was the following:[16]

"On March 10, Schultze and Messing conducted about 16-hour long testings of the ventilation system of the gas chamber of Crematory II. Apparently the installation was still not working properly, since Messing worked there again on the 11th for another eleven hours, and once again on the 13th for fifteen hours. Tests were made after the addition of Zyklon B. The detection of hydrocyanic acid residues was apparently performed through a chemical process and not by gas testers, because these had been ordered too late to have been delivered on time."

In the following discussion – which recapitulates and adds to what was presented in the study entitled, Auschwitz: End of a Legend[7] – I will on the one hand demonstrate that Pressac's interpretation is both historically groundless and technically absurd, while I will on the other hand present an alternative explanation which is compatible with the historical and technical context which forms the background of the documents.

2. The Purpose of the "Gas Testers"

Pressac's explanation is incorrect technically and groundless historically. The idea of de-aeration from the bottom being unsuitable for a hydrogen cyanide gas chamber has no technical foundation, and in fact in the diagrams of the Zyklon B delousing chambers with DEGESCH circulation design, the induction inlet was situated randomly in the upper or the lower part of the gas chamber.[17] The quality of ventilation depends only on the power of the ventilators (both exhaust and intake). But even if de-aeration from the top were indispensable for a hydrogen cyanide gas chamber to operate correctly, Pressac's explanation would still be groundless, because the ventilation system of Morgue 1 of Crematory II was installed the other way around, that is, with air intake from the bottom and exhaust from the top: the decision to switch the position of the ventilators was made by Topf in March 1942[18] or several months before the alleged (undocumented) decision of the Central Construction Office to convert Morgue 1 into a homicidal gas chamber. Accordingly, since the ventilators had been reversed and the Central Construction Office was well aware of that fact, Pressac's explanation remains groundless.

Ill. 2: Document in facsimile in: J.-C. Pressac, Die Krematorien von Auschwitz, Piper, Munich 1994. Doc. Plate No. 28 (original in Tsentr Chranenija Istoriko-dokumental'nich Kollektsii, Moskau, 502-1-313, p. 44.). Translation:

"[...] We confirm the receipt of your telegram, saying:

'Send off immediately 10 gas detectors as discussed. Hand in estimate later'."

In this regard, we let you know that already two weeks ago we asked 5 different firms about the display devices for hydrocyanic acid residues requested by you. We received negative answers from 3 firms, and from two others an answer is still outstanding.

In case we receive notification in this matter, we shall get close to you immediately so that you can get in contact with the firm producing these devices.

H a i l  H i t l e r ! [...]

So why then would the Central Construction Office have ordered "gas testers"? What purpose were they supposed to serve? Pressac's explanation that the "detection of hydrocyanic acid residues was apparently performed through a chemical process and not by gas testers" is also historically and technically unfounded. In fact, on the one hand there is no document, which has ever mentioned the "detection of residues of hydrocyanic acid," and on the other hand the test for hydrocyanic gas residues (gas residue test) could be performed exclusively "through a chemical process," i.e., with the procedure which was developed by Pertusi and Gastaldi and further improved by Sieverts and Hermsdorf.[19]

If then, according to Pressac, the test for gas residues was performed "using a chemical process" instead of "with gas testers," these testers did not operate according to a chemical procedure, so they could not have been used for gas residue testing.

With the aforementioned "trace," Pressac involuntarily demolishes his entire line of reasoning: in fact, the technical term for a device used to test for hydrocyanic gas residues was neither "gas tester" nor "display devices for hydrocyanic acid residues" but was, instead, "gas residue detection devices for Zyklon" (see Ill. 3).

This device was not an instrument but rather a small kit containing various chemical products (see Ill. 4). An official publication of the Waffen-SS provides detailed explanations in this regard:

Gas Residue Detection

The testing is performed by the disinfestation supervisor or his deputy, by means of the required equipment for gas residue detection (according to Pertusi and Gastaldi). This equipment consists of:

  • One small clear bottle of Solution I (2.86 g of copper acetate in 1 ltr of water),
  • One small brown bottle with Solution II (475 ccm at room temperature of a saturated solution of benzidine acetate, filled up with 1 ltr of water),
  • One small test-tube with calcium cyanide and cork plug,
  • Three small test-tubes with cork plugs for storing moist paper strips,
  • One small clear tube with powder for 1/2 liter of Solution I,
  • One small brown tube with powder for 1/2 liter of Solution II,
  • One officially certified color chart, blotting paper strips no. 597 from Schleicher-Schüll, Düren.
  • Directions for the Gas Residue Detection Device

Pour equal parts of Solution I and II into the mixing container; cover with plug and shake. Dip a few blotting-paper strips half way into the mixed solution. By dipping them into the test tube with calcium cyanide, examine whether the mixed liquid solution reacts to Hydrocyanic acid (blue coloring!). In case blue coloring occurs, the already aired room is to be examined using more soaked blotting strips. This work is done while wearing a gas mask. Any time after ten seconds, when no significantly stronger blue coloring occurs than the weakest color tone on the chart, the chamber may be opened without hesitation; otherwise, one must air again and repeat the test.

Ill. 3: Letter of Tesch & Stabenow to the administration of the POW Lublin (Majdanek) of July 29, 1942. Archiwum Panstwowego Muzeum na Majdanku, sygn. I-d-2, Dd. 1, p. 107.

The production of Solution I and II is accomplished in the following manner: The contents of a brown test-tube (Solution I) and a clear test-tube (Solution II) is to be dissolved into a half liter of distilled water and this solution is to be filtered. Solutions showing a residue at the bottom of the test-tube are not usable and are to be poured away. Solutions I and II must only be combined shortly before the testing.

The little color charts are to be renewed after five years.

Only after the careful procedure of testing for gas residues even between objects stacked on top of one another result in no traces of hydrocyanic acid, the building may finally be opened up. Otherwise one is to aerate again and repeat the test."[20]

3. Historical Background

The telegram sent by the Central Construction Office was issued during a strong recrudescence of the typhus epidemic, which broke out in Auschwitz in early July 1942.

On February 8, 1943, SS Obersturmbannführer and Kommandant Rudolf Höß issued Order no. 2/43, which announced the following to all his subordinates:[21]

"By order of SS Brigadier General and General of the Waffen SS Glücks, a total quarantine is issued for Auschwitz concentration camp. The order of the Office Group Chief, transmitted by teletype, states as follows, i.a.: 'Because of the high incidence of typhus, all permissions for furlough or leaves must be canceled.'"

On February 12, SS Sturmbannführer Karl Bischoff, head of the Central Construction Office, sent a letter to Office Group Chief C of the SS WVHA, SS Brigadier General and General of the Waffen SS Hans Kammler, to inform him about the measures ordered by Glücks. Bischoff wrote:[22]

"Because of the rise of typhus cases among the guards, on February 9, a total quarantine was issued for Auschwitz by SS Brigadier General and General of the Waffen-SS Glücks.

In connection with this, all prisoners will be disinfected on February 11 and are not allowed to leave the camp, which means that all construction projects, on which prisoners were employed, must be halted.

The resumption of work will be announced by the Central Construction Office."

In response to the letter of the previous day, Bischoff advised the head of Main Department C/VI of the SS WVHA (Wirtschaft-Verwaltungshauptamt, Economic Administrative Main Office), SS Standartenführer (Colonel) Eirenschmalz, on February 13:[23]

"more cases are increasingly accumulating, since also civilian workers are becoming inflicted with typhus. For all those civilian workers who lived together with those who got sick, the physician in charge orders a three weeks quarantine."

In order no. 3/43 dated February 14, Höß precisely defined the limits of the prohibited area and conveyed the stipulations of the SS camp physician:[24]

"Delousings will be conducted with permission of the SS camp physician […]. The instructions of the SS camp physician regarding disinfestations of the guards of transports have to be followed strictly."

Referring to the letter dated the 12th, Bischoff informed Kammler on February 18:[25]

"the disinfesting of prisoners was concluded and work was resumed on February 16."

In a letter of Feb. 25 to the head of office D III of the SS WVHA, the SS camp physician of Auschwitz summarized the situation of the existing in the camp:

"As already reported, after that typhus epidemic was practically under control, a new rise in typhus cases occurred in November and December among the inmate population as well as among the troops because of the arrival of new prisoners from the East. In spite of immediate measures against the disease, a complete stop has not been achieved."

The SS camp physician intended to adopt drastic measures to eliminate the epidemic once and for all, the most important of which was to carry out general disinfestation:[26]

"With the exception of vital commands (food production, farm workers in cattle care and necessary office personnel), all working troops in the largest areas of Auschwitz concentration camp, namely main camp, male and female concentration camp Birkenau, and POW, construction section 2, should all be closed for three weeks. During this time, a major delousing and disinfestation will be conducted twice so that after the three-week quarantine, one cannot refer anymore to a lice infestation of the camp, and the danger of typhus will be erased."

On the following day, February 26, 1943, the Central Construction Office sent the following telegram to the Topf company:[27]

"Send off immediately 10 gas testers as discussed. Hand in estimate later."

If these "gas testers" had in fact been "display devices for hydrocyanic acid residues," then the Central Construction Office's request would have been more consistent with the actual historical context of a typhus epidemic being fought throughout the camp by using hydrocyanic acid (Zyklon B) than with the purely hypothetical context of a presumed installation of an alleged homicidal gas chamber in Morgue 1 of Crematory II. I call it a purely hypothetical context, because the Topf letter dated March 2, 1943, in and of itself proves nothing; as I have demonstrated elsewhere,[28] Pressac offers here a classical example of circular logic: the "gas testers" have a criminal function because in Crematory II there was a homicidal gas chamber – and vice versa there was a homicidal gas chamber in Crematory II because the "gas testers" have a criminal function!

Ill. 4: Photo of a "Gasrestnachweisgerätes für Zyklon," (gas residue detection device for Zyklon, gas test kit) as discovered by the Soviets in Auschwitz. Archiwum Panstwowego Muzeum w Oswiecimiu, nr. neg. 627.

The historical context would therefore strengthen Robert Faurisson's interpretation, wherein these – presumed, I might add – display devices were used for normal disinfestations of the crematorium.[29] In support of this interpretation, it could be added that according to the general provisions of the SS camp physician, 200 detainees who were working in late February 1943 in Crematory II[30] would have been able to resume their activity only after a disinfestation of their bodies and of their work-place, i.e., Crematory II.

That the disinfestation of the morgue of a crematory was standard procedure when the deposited cadavers of deceased prisoners had died of typhus, can be deduced from the following disposition by the president of the Kattowitz police concerning the inmates of the auxiliary prison of the police at Myslowitz, where typhus fever was widespread in January 1943:[31]

"Those who died of typhus must be treated with a disinfecting lice-killing liquid and must be placed into coffins as soon as possible. The coffin must be immediately closed and transferred to a special hall. For cremation, the dead will be brought to Auschwitz with the hearse."

In summary, even if Pressac's preliminary assertions were true, his conclusions would be historically groundless and the historical context would lend credence to Faurisson.

But are Pressac's preliminary assertions true? To answer this question, we need to examine the bureaucratic context of the documents.

4. The Bureaucratic Context

In January 1943, the Central Construction Office had reached the height of its organizational development and was divided into 14 departments and five construction offices. The departments were as follows:

  1. department building construction,
  2. department underground construction,
  3. department watering,
  4. department drainage and surveying,
  5. department planning,
  6. raw materials and purchases,
  7. administration,
  8. drivers,
  9. technical department,
  10. work deployment,
  11. craftsman shops,
  12. carpentry and roofing,
  13. gardening,
  14. department statistics.

The five Construction Offices were as follows:

  1. Construction Office of the Waffen-SS and Police Auschwitz. Auschwitz concentration camp and farming Auschwitz,
  2. Construction Office of the POW,
  3. Construction Office industrial area Auschwitz,
  4. Construction Office main economic camp of the Waffen-SS and Police Auschwitz and troop supply camp Oderberg,
  5. Construction Office factory and Manor Freudenthal and Manor Partschendorf.[32]

The Central Construction Office was performing exclusively construction duties, and therefore was subordinated under office Group C (Constructions) of the SS WVHA directed by SS Brigadier General and General of the Waffen-SS Hans Kammler. Financial matters – including payment of bills from private companies – were handled by Office V/2a (Economics and Invoicing).

Medical/sanitation duties – including the purchasing and use of hydrocyanic acid (Zyklon B) – were the exclusive territory of the SS camp physician, who was subordinated under Office Group D III of the WVHA, directed by SS Lieutenant Colonel Dr. Lolling. In February 1943, the SS camp physician of Auschwitz was SS Hauptsturmführer (Captain) Eduard Wirths; his deputy was SS Hauptsturmführer Krebsbach. Under the camp physician were the troop physicians, who handled medical care for the troops, the camp doctors, who handled the detainees, and the nursing ranks (Sanitätsdienstgrade, SDG), specially appointed auxiliary personnel comprised of SS Unterscharführer or SS Männer (sergeants, privates). Each camp and each camp section had its own camp doctor. The camp doctor of the POW Birkenau was SS Obersturmführer (1st Lieutenant) Vetter.

One of the most important duties of the SS camp physician was preventing and combating the recurrent typhus epidemics with all the medical/sanitation measures that this involved, including disinfestations. He had direct responsibility not only for the disinfestation apparatuses of the camp but also for disinfestation of individual buildings or entire construction sections of the camp. This latter activity was carried out by a division of the nursing ranks, the Desinfektionskommando, directed by SS Oberscharführer (Technical Sergeant) Joseph Klehr.

The Zyklon B used by disinfectors and any other material needed for disinfestations was procured in the following manner: the SS camp physician sent a written request to the head of the administration, stating the reason. The latter forwarded the request to Office D IV of the SS WVHA. Once approval was received from the supervisor of this office, SS Sturmbannführer (Major) Burger, who was then the head of the administration, sent the request to the Tesch & Stabenow company together with the necessary Wehrmacht bills of lading for shipping the load. The material could also be picked up from the Zyklon B factory at Dessau, and the Dessauer Works would then give notice by telegram that the Zyklon B was "ready for pick-up."[33]

Ill. 5: Description of a gas tester ("Gasprüfer") in German expert literature: Hütte. Des Ingenieurs Taschenbuch, W. Ernst & Sohn, Berlin 1931, vol. 1, p. 1011 (top) + 1013 (bottom).

Bills from Tesch & Stabenow were paid by Office D IV/1 of the SS WVHA. Thus, the disinfectors of Auschwitz received not only Zyklon B but also the entire disinfestation equipment, which was also supplied by the Tesch & Stabenow company, i.e., iron cutters for opening the Zyklon B cans; rubber lids; gas masks; special "J" filters; and the famous "gas residue detection devices for Zyklon." The camp physician, or by delegation any camp doctor, was responsible for storage, use, and maintenance of all this material.

It is important to point out that this bureaucratic chain of command would still have ruled even if Zyklon B had been used for criminal purposes. In practice, in Auschwitz it was not possible to use Zyklon B without the authorization and knowledge of the SS camp physician.

5. Problems Pressac Left Unresolved.

From what has been said above, it is clear that the two documents on "gas testers", according to Pressac's interpretation, present serious interpretative problems, which the French scholar has chosen to ignore.

Let us begin with the most important one, which he raised in 1989 and left unresolved: because these "gas residue detection devices:"

  1. belonged to the area of responsibility of the SS camp physician;
  2. were distributed by the Tesch & Stabenow company;
  3. were called "gas residue detection devices" and not "gas testers";
  4. were necessarily available at Auschwitz in February 1943;

then why they were they:

  1. called "gas testers" rather than "gas residue detection devices;"
  2. requested by the Central Construction Office rather than by the SS camp physician;
  3. requested from the Topf firm rather than from Tesch & Stabenow;
  4. even though they were readily available at Auschwitz?

Let us examine in detail these objections.

a) If Pressac's interpretation were to be accepted, there would have been a consequence, which the French historian did not take into consideration: a possible check of the ventilation system of Morgue 1 for homicidal gassings with Zyklon B would have been the task of the SS camp physician and would have consequently been organized and performed by the disinfectors, while Messing would have been limited to his own area of competence, the ventilation mechanics. Therefore, if the Central Construction Office, who were knowledgeable about the technical terminology of their specialization, could not perform this check without the disinfectors, how would the request for "gas testers" instead of "gas residue detection devices" be explained?

Now let me address point b): The Central Construction Office had no responsibility for the ordering of "gas residue detection devices," as it would not have been responsible for ordering Zyklon B. If it had actually ordered them, it would not have been able to pay for them, since these devices were not within the administrative domain of Office V/2a of the SS WVHA. In other words, the invoice would have left unpaid – and anyone who knows the Central Construction Office documentation knows what a major bureaucratic problem this would have been – unless Bischoff had wanted to pay for the "gas testers" out of his own pocket!

Pressac also dodges another fundamental problem: a possible check of the ventilation system of Morgue 1 of Crematory II to ascertain its suitability for the use of hydrocyanic acid with homicidal intent, which would necessarily have required the following:

  1. Zyklon B
  2. gas masks
  3. filters "J"
  4. iron cutters
  5. gas residue detection devices

But then why would Central Construction Office have ordered "gas testers" just by themselves? Evidently because it had no need for the rest of the material, because it could obtain all of it by sending a request to the SS camp physician. But if that is so, then it could also have obtained the gas residue detection devices for Zyklon in the same manner; so what need would there have been to request it from the Topf company?

In this context, the Pressac assertion, according to which "Tests were made after the addition of Zyklon B," raises even more problems: if this (totally unsupported) claim were true, from whom would the Central Construction Office have requested Zyklon B – from the Topf company or from the camp physician? This problem is purely hypothetical, however, because the assertion in question not only has no documentary foundation, but is in obvious contradiction to the reports of Messing's work and even to Pressac's own comments in this regard. Messing performed the following work:

  • March 10 and 11, 1943: "tested, on trial basis, to install aeration and de-aeration system for morgue cellar 1;" 16 and 11 hours of work respectively.
  • March 12, 1943: "worked on the ventilation system for undressing cellar;" 11 hours of work.
  • March 13, 1943: "aeration and de-aeration system of Cellar 1 put into operation;" 15 hours work.[34]

Pressac comments:

"Apparently the installation did not work properly, since on the 11th, Messing worked on it for eleven more hours, and then on the 13th, he worked there again for fifteen hours."

Therefore on March 10, 11, and 13, Messing was simply conducting experiments in mechanical ventilation. So when was this "testing" with Zyklon B supposed to have been carried out, seeing that the first homicidal gassing was supposed to have been carried out "on the night of the 13th to the 14th of March 1943"?[35] And why did Messing never refer to it? All this gets even more mysterious because Messing, according to Pressac, allegedly wanted to reveal the "truth" partially by using the term "undressing cellar" instead of "morgue" in this work-time sheet.[36]

Let us now move to point c): Suppose hypothetically that the SS camp physician were temporarily out of gas residue detection devices for Zyklon. Why would the Central Construction Office have had to request them from Topf – a company that neither produced them, sold them, nor even knew who would handle them – instead of ordering them from Tesch & Stabenow, the company that definitely did sell them, as the camp physicians must have been well aware? Pressac's explanation of this problem is absurd: according to the letter dated March 2, 1943, Topf would not have acted as a go-between to cover up the alleged secrets of Auschwitz (as Pressac claims), but would simply have put the Central Construction Office in contact with a companies who furnished these devices:

"In case we receive notification in this matter, we shall get close to you immediately so that you can get in contact with the firm producing these devices."

In other words, Topf would have had to request gas residue detection devices for Zyklon from Tesch & Stabenow, and if Tesch had had any available, Topf would have put the Central Construction Office in contact with them! This absurd procedure would have had the opposite effect to the one presupposed by Pressac: if the Tesch & Stabenow company would have received an order for gas residue detection devices from the Central Construction Office rather than from the camp administration, as was the normal practice, this would have been reason for suspicion!

This takes us to the last point d): The hypothesis proposed in point b) that the SS camp physician was at that moment out of gas residue detection devices has little credence because the detection of gas residues was not only a matter of regulation,[37] but also legally obligatory,[38] because this test was a necessary and indispensable complement to the use of hydrocyanic acid gas anywhere and at all times, and hence at Auschwitz in February 1943. The availability of gas residue detection devices can be deduced with a sufficient degree of certainty as well. They were available even in January 1945: the Soviets found some in the "reception hut with delousing" (BW 28) and took photographs of them (see Ill. 4). So then what reason could there have been to request some from the Topf company?

6. What Exactly Were the "Gas Testers"?

Now that the interpretation of Jean-Claude Pressac has been shown to be groundless, it is time to provide an alternative explanation, which would cover all the aforementioned problems left unsolved by the French historian.

I shall begin by pointing out that the German term for gas testers – Gasprüfer – was the technical term for an instrument for smoke gas analysis (Rauchgasanalyse), which was operating "by physical methods" (see Ill. 5). In the early 1940s, there were various instruments for the analysis of combustion gases, like smoke gas analysis devices, sensors and displays for the percentage of CO2, and for the percentage of CO and H2 combined (see Ill. 6).

Crematory ovens were equipped with one of these instruments as standard. Engineer Richard Kessler, one of the foremost German cremation experts during the 1920s and 1930s, recommended as "absolutely necessary" for the proper functioning of crematory ovens the installation of a series of devices, including:[39]

"a CO/CO2 gauge in good working condition, to insure an economical cremation, which also monitors smoke development."

Even in the beginning of the 1970s, engineer Hans Kraupner advised:[40]

"For a fast elimination of smoke development, it is important that the gauges must be installed directly behind the oven and must give a signal to the oven attendant right at the beginning of smoke development."

The more reasonable hypothesis is therefore that the Central Construction Office had ordered "gas testers" for the crematory ovens of Birkenau. We shall now see if this hypothesis solves all the problems indicated above.

The telegram dated February 26, 1943, bears the following information typed by the sender:

"Central Construction Office Auschwitz sgn. Pollok SS Untersturmführer"

It also has three handwritten notes:

At top right, the abbreviation BW 30 (Bauwerk 30 = Crematory II); at bottom left is the abbreviation "Jäh", the initials of civil employee Jährling; finally, at bottom left, near the date and time the telegram was sent, the name of Kirschnek preceded by the abbreviation of his rank "Unstuf." (= Untersturmführer, Second Lieutenant; see Ill. 1).

The March 2, 1943, Topf letter (see Ill. 2) shows a registry stamp of March 5, 1943, and also has two handwritten initials: those of Jährling (on the left) followed by a date of March 8, 1943. This letter also indicates the initials of Janisch (at the right), preceded by the date March 6.

Let us consider, first of all, who these persons were and what duties they performed within the Central Construction Office.

SS Untersturmführer Josef Pollok was the head of the Construction Office Main Economic Camp of the Waffen-SS and Police Auschwitz and Troop Supply Camp Oderberg; SS Untersturmführer Hans Kirschnek was the head of the Construction Office of the Waffen-SS and Police Auschwitz, concentration camp Auschwitz and farming Auschwitz; SS Untersturmführer Josef Janisch was head of the Construction Office of the POW; and finally the civilian employee Rudolf Jährling – his profession being heating technician – was part of the technical department.

The telegram dated February 26, 1943, was drawn up by SS Untersturmführer Pollok, because his jurisdiction – relating in general to the construction of buildings and in particular to matters relating to construction economics, construction police, construction applications, quota determination, etc. – also extended to the Construction Office of the POW.[41] SS Untersturmführer Kirschnek, on the contrary, had no jurisdiction over the POW of Birkenau and probably was responsible only for sending the telegram. His handwritten name, which appears in this document, was not written by him, as this was not his signature style.

The most important person involved in that telegram was Jährling himself who, on account of his thermo-technical specialty, was responsible for all the heating and combustion facilities in the camp. The largest of such facilities was the district heating plant, which consumed 45-50 tons of coal each day.[42] Jährling was also responsible for thermo-technical matters relating to the crematory ovens; for example, he was the author of the memo dated March 17, 1943, regarding the evaluation of coke consumption of the crematoria of Birkenau.[43] In 1944, Jährling headed the heating technical department of the Central Construction Office. The fact that Jährling – a heating technician – was involved in the request for "gas testers" is therefore further confirmation of the fact that these were simple instruments for the analysis of the combustion gases in the crematory ovens. Moreover, this interpretation fits well with the historical context.

On January 29, 1943, engineer Prüfer inspected the construction sites of the crematoria and compiled a report, in which he noted in regard to Crematory II:[44]

"The five 3-muffled cremation ovens are finished and are currently being heat-dried."

In his activity report dated March 29, 1943, Kirschnek jotted down the following for Crematorium II:[45]

"The whole masonry work completed and on February 20, 1943, put into operation."

It is therefore clear that the Central Construction Office, in ordering smoke gas testers, wanted to ensure optimum combustion in the crematory ovens. And it is also clear that for this reason the Central Construction Office, in order to obtain these thermo-technical instruments, turned to Topf, a "machine factory and firing-technical construction company."[46]

One last question, which Pressac preferred to ignore, needs to be clarified: why did the Central Construction Office order exactly ten "gas testers"? The answer is simple: they were intended for the ten smoke flues in Crematories II and III, or for the ten chimney ducts of Crematory II-V.[47] The abbreviation "BW 30" on the telegram dated February 26, 1943, does not necessarily mean that the "gas testers" were intended for Crematory II only; this, as in other cases, could mean that the administrative jurisdiction of the purchase belonged to the registry of BW 30.[48]

In summary, if the "gas testers" were simple analyzers of combustion gas, then it is perfectly understandable:

  1. why they were ordered by the Central Construction Office (and not by the SS camp physician);
  2. why they were ordered from Topf (and not from Tesch & Stabenow);
  3. why they were ordered with the name of "gas testers" (and not "gas residue detection device for Zyklon");
  4. what their function was;
  5. why exactly ten were ordered;
  6. why Zyklon B, gas masks, filters "J" and iron cutters were not ordered in addition to the "gas testers."

Let us finally move on to the Topf letter dated March 2, 1943. As already stated, this bears the initials of Janisch, the head of the Construction Office of the POW, and the initials of Jährling, which fits perfectly with the interpretation given above.

As for the text of this letter, I should point out first of all that the request for information by Topf ("already two weeks ago") was made at least ten days before the telegram from Central Construction Office, which refers to a previous conversation ("as discussed"), of which, however, there is no trace in the documentation.

The wording of the telegram – ("Send off immediately") – leads one to think that Topf already had the "gas testers" available.

The next mention of the estimate as well as Topf's response raises another problem, because according to the bureaucratic practice, upon the request from Central Construction Office, Topf – as was the procedure with all the other companies – submitted a bid in the form of an estimate; if the bid was accepted, the Central Construction Office would make the order, which could be verbal, and then would always confirm in writing. Within this bureaucratic procedure, the German word used here – "Kostenangebot" (cost offer) – was not the term used in practice; the designation was always "Kostenanschlag" (cost estimate). But with these documents, which we are questioning, the normal practice is reversed, and we are asked to believe that the order by the Central Construction Office preceded the bid and the company's estimate, which was contrary to the normal bureaucratic practice. Instead of the normal practice, we have on the one hand the Central Construction Office, which could not order an item before a company had sent in the related bid with an estimate, and on the other hand we have Topf, which could not submit a bid with an estimate for something, which it neither produced nor sold. So why should the Central Construction Office have requested an estimate for a product from the Topf company, when it must have known that Topf did not sell this product?

But that is not all: because gas residue detection devices for Zyklon were normally distributed by the Tesch & Stabenow company, by the Heerdt & Lingler company, or by DEGESCH, then Topf's difficulty in locating them is incomprehensible.

And there is another point to be stressed: it is incomprehensible why the Central Construction Office would have directed its request to the Topf firm instead of directing it to the local SS camp physician.

Finally, as I have indicated, the term "Anzeigegeräte für Blausäure-Reste" (display devices for hydrocyanic acid residues) did not exist at all; the term "display" has absolutely nothing to do with a chemical device, but rather with an instrument. It designated either the entire instrument (Anzeigeinstrument) or the indicator in that instrument; as an example, I may refer to known instruments for measuring the percentage of CO2 and of CO+H2, see the illustration 6.

Ill. 6: Photo of two gauges ("Anzeigegeräten") by Siemens for CO2 (right) and combined CO+H2 content (left) in %. Alberto Cantagalli, Nozioni teorico-pratiche per i conduttori di caldaie e generatori di vapore, G. Lavagnolo Editore, Turin 1940, p. 308.

The decisive point is as follows: If one substitutes the term "display devices for hydrocyanic acid residues" (Anzeigegeräte für Blausäure-Reste) with "display devices for smoke gas analysis" (Anzeigegeräte für Rauchgasanalyse), all problems discussed above disappear instantaneously![49]

My conclusions are thus as follows:

  1. The "gas testers" mentioned in the telegram of Feb. 26, 1943, were simple smoke gas analyzers for the crematories.
  2. The Topf letter of March 2, 1943, has been produced by an amateurish forger, who concocted a new term "display devices for hydrocyanic acid residues."

Admittedly, this conclusion also produces some problems. They were pointed out by an anonymous commentator; however, the argumentation and style suggest that the author was actually Pressac himself. He wrote:[50]

"The revisionists dismiss this document by claiming that it is a forgery. The forger must indeed have been a remarkable historian, because he did not only know name and signature of the head of the SS Central Construction Office at Auschwitz, Karl Bischoff, of one of his coworkers, SS sergeant SDS Hans Kirschneck, of the civilian employee Rudolf Jährling who was responsible for technical matters, of the responsible person of department D of the Topf firm, chief engineer Fritz Sander, as well as of the head of Division D IV of the Topf firm (crematory construction), chief engineer Kurt Prüfer. The forger had access to paper with the letter heads of the Topf firm as it was in use in March 1943, to a Topf rubber stamp as well as a rubber stamp and a dating stamp of the Central Construction Office Auschwitz, and in addition to that their complete registry of correspondence, so that the letter could get an exact receipt number. He was also familiar with the administrative customs of the Topf firm and knew who had power of attorney (Sander) and who did not (Prüfer)."

In my eyes, this critique is rather simple-minded. No serious revisionist assumes a complete forgery of this document, but some revisionists, including myself, consider it to be a tampered document. Apart from that, the thesis of a forgery is not proposed in order to dismiss this document, but because it causes severe historical, technical, and bureaucratic problems.

"Tampering" with a document means the changing of an authentic document, which could, for instance, consist in the replacement of the words "Anzeigegeräte für Rauchgasanalyse" by "Anzeigegeräte für Blausäure-Reste." It should also be kept in mind that the Soviet occupational powers had access to the letter heads and stamps of both the Auschwitz administration and the Topf company, because they had confiscated the archives and office materials of both entities.

I may finally indicate that the problems resulting from a possibly-tampered document are remarkably less difficult to explain than the unsolvable problems resulting from the assumption that this is, indeed, an authentic document.

Pressac surely will reject these conclusions, but if he does, he will have to provide serious answers to the questions raised here.

Editor's Remark

Between the first publication of this paper in early 1998 (both in print and online) and J.-C. Pressac's death in 2003, he never responded to Mattogno's questions.

Auschwitz: "Gas Testers" and Gas Residue Test Kits

By Carlo Mattogno

1. Introduction

In the article above, which was first published in German in 1998,[51] I analyzed within their historic, technical, and bureaucratic contexts two documents, which were interpreted by the late Jean-Claude Pressac – and the "official" historians after him – as "criminal indictments," if not "definite proof," of the existence of a homicidal gas chamber in Crematory II in Birkenau. It concerns a telegram from the Central Construction Office of Auschwitz to the Topf firm on February 26, 1943, about an order of "10 gas testers," and the answer from the Topf firm dated March 2 of the same year, which identified these instruments with some imaginary, non-existing "display devices for hydrocyanic acid residues."

Actually, Pressac's allegation that he furnished a proof for the reality of homicidal gas chambers, is totally unfounded, as I have already shown with numerous arguments. These "gas testers" were actually simple devices for the analysis of smoke gases using a physical method, while the "display devices for hydrocyanic acid residues" never existed. The equipment used for analyzing air for residues of hydrocyanic acid was actually called a "gas residue detection device" – or less strictly translated: a gas test kit – which worked on a chemical basis.

In the previous article, I also indicated that everything in Auschwitz in any way connected to disinfestations with hydrogen cyanide fell under the responsibility of the SS camp physician, who had all necessary fumigation accessories at his disposal: Zyklon B, gas masks, filters type "J" for the gas masks, iron cutters as can openers for the Zyklon B cans, and gas test kits for the gas testing.

But to what extent were wartime German civilian directives for the application of hydrocyanic acid during fumigations – especially the gas residue tests – also binding for concentration camps? The present article deals with this important question as well as other subjects related to the application of Zyklon B.

2. German Standards on Gas Residue Tests after Hydrocyanic Acid Disinfestation

After the First World War, the German standard for the regulation of the application of hydrocyanic acid for fumigation was the "Directive about fumigation of vermin with highly poisonous materials" of January 29, 1919,[52] which was, however, rather general. It limited itself to questions about who is authorized to handle hydrocyanic acid. The subsequent "Directive for the use of the directive about fumigation of vermin with highly poisonous materials" of August 22, 1927,[53] contained only a few additional clarifications of the law of January 29, 1919.

A revised "Directive about fumigation of vermin with highly poisonous materials" was enacted on March 25, 1931,[54] which combined both previous laws, but included also for the first time actual regulations for the application of hydrocyanic acid disinfestations.

Paragraphs 6 and 7 dealt with safety precautions:[55]

"§ 6. Each person who is working with the application of the mentioned material has to be equipped with the following:

a well fitting gas mask with a filter insert especially suitable for the decontamination of the material mentioned in the directive. The mask has to be ready to be put on at any time during all work with highly poisonous material and during all inside work. The inserts have to be provided with the date of manufacture; in case that they are older than two years, they shall not be worn, even if unused.

§ 7. Furthermore must be held ready locally:

a mouth piece with breathing insert and nose clamp for work with highly poisonous materials on the outside.

an oxygen-breathing apparatus with instructions for the treatment of gas poisoning,

three additional gas masks as per § 6 for different head sizes and the required number of inserts,

a set of equipment to administer life saving sterile injections below the skin (0.01 gram lobelin and 0.25 gram caffein-sodium-benzonate or other medications approved by the Imperial Government) and in case of injuries the necessary bandages and instructions with special directions for first-aid of gas poisoning,

a complete set of equipment for the testing of gas residuals in accordance with a procedure recognized by the responsible authorities."

Paragraph 11 contained directions for what to do after completion of a fumigation:[5]

"After completion of the gassing, the buildings shall be thoroughly aired by opening the doors, windows, and other possibly existing air inlets, and by starting existing ventilation installations. Furniture with upholstery, pillows, beds, carpets, blankets, curtains, clothes, and similar objects have to be thoroughly beaten and shaken under the supervision of the fumigation supervisor or his delegate, possibly outdoors in the open air. After the airing of the fumigated rooms or buildings, which must last for at least twenty hours (which can be reduced in special cases through appeal to the authority in charge), all objects, which were removed for outdoor beating and shaking, shall be returned and then all doors, windows, and all other air inlets shall be closed for one hour. In rooms that can be heated the temperature shall be brought up to at least 15 degrees Celsius. After that a gas residue test has to be performed by the fumigation supervisor.

If, after careful testing for gas residues even between blankets, mattresses, etc., no traces of hydrocyanic acid can be found, the building can be released; otherwise the airing has to be continued and the gas residue test has to be repeated".

The Circular of the Minister for Welfare of August 8, 1931, about "Fumigation of vermin with highly poisonous materials"[56] included detailed instructions about the prevention of accidents and warned against the extreme danger of hydrocyanic acid:

"Toxicity of hydrocyanic acid: Hydrocyanic acid is one of the most potent gaseous materials. Only a few breaths of air, which is heavily saturated with hydrocyanic acid, will certainly lead to death".

The circular also contained an exact description of the gas residue test:[57]

"c) The most useful procedure considered to measure gas residues (§ 7d) is the benzidine-copper-acetate-reaction according to Pertusi and Gastaldi; the following equipment is needed for its implementation, which has to be available on the premise according to § 7:

  • 2 small clear bottles of solution I (2.86g of copper acetate per 1 liter of water),
  • 2 small brown bottles with solution II (475 ccm at room temperature of a saturated solution of benzedine acetate, filled up with water to 1 liter),
  • 1 small test-tube with cork plug to store the wetted paper strips,
  • 2 clear test-tubes with copper acetate for half a liter of solution I,
  • 2 brown test-tubes with benzedine acetate powder for one half liter of solution II,
  • 1 color chart
  • Blotting paper strips.

This equipment has to be ready on the premises.

Test procedure:

Fill the mixing container with equal amounts of solutions I and II, shake well after closing with the plug, moisten the lower half of a couple of blotting paper strips by emerging them into the mixing container and store each strip in a closed test tube until ready to be used. The freshly prepared paper strips will clearly turn blue within 7 seconds if there is danger of hydrocyanic acid poisoning within the tested area".

The "Directive for the use of the directive about fumigation of vermin with highly poisonous materials" of November 4, 1932,[58] regulated the "arrangement and use of fixed rooms for fumigations."

The "Circular of the Reichsminister for Nutrition and Agriculture and of the Reichsminister of the Interior" of November 4, 1941, combined all previous instructions, including those about the gas residue test. About the application of gas masks the document established:[59]

"It has to be especially emphasized that it is necessary to renew the gas mask inserts on time. A gas mask insert can only be used for one hour while working in air containing up to 1 percent by volume of hydrocyanic acid.[60] In air with a higher concentration of hydrocyanic acid (up to 2 percent by volume[61]) the inserts can only be used for half an hour. The inserts shall not be older than two years. These limits have to be obeyed, even if any effects of the warning ingredient, which were added to the hydrocyanic acid, cannot be noticed."

The "Directives for the Application of Hydrocyanic acid (Zyklon) for the Fumigation of Vermin (Disinfestations)",[62] issued by the Health Institute of the Protectorate Bohemia and Moravia in Prague comprised all essential directions for a correct disinfestation with Zyklon B. With regard to the first-aid in case of poisoning, each fumigator had to carry with him the directive: "First-aid in Cases of Poisoning with Hydrocyanic acid", and each disinfestation team had to have at its disposal "1 set of the necessary equipment to inject lobelin. Vials with 0.01 g lobelin. (Cardiozol), Veriazol tablets."[63]

But were these directions also valid for concentration camps?

3. The Rules for the Handling of Hydrocyanic Acid for Disinfestation in the Gusen camp

A little document gives a complete answer to this question. It is a "Service Instruction for the Operation of the Hydrocyanic Acid Fumigation Chamber in the Concentration Camp Gusen," which was prepared by the SS camp physician of the Concentration Camp Mauthausen, SS Hauptsturmführer Eduard Krebsbach. The following is the complete text:[64]

"SS camp physician Mauthausen

Mauthausen, 2/26/1942

Service Instruction

for the Operation of the hydrocyanic acid fumigation chamber in the Concentration Camp Gusen

The work with and in the hydrocyanic acid fumigation chamber is extremely dangerous if the following operational instructions are not precisely followed.

During the work inside the hydrocyanic acid chamber, the supervising and working personnel must wear special work clothes, which are tied closed at the hands and feet. After completion of work the work clothes must be immediately taken off and kept in the front room. It is strictly forbidden to take work clothing to the living area.

Before entering the hydrocyanic acid chamber in order to load it, is absolutely necessary to test for gas residues.

Loading moist articles into the gas chamber is not allowed.

The gas residue test equipment has to be checked weekly by the pharmacist of the concentration camp Mauthausen for its usefulness.

During the loading procedure of the gas chamber, all doors and windows are to be kept open. Pieces of clothes, blankets, etc. are to be placed on the racks provided.

After the chamber is loaded, it has to be heated during half an hour to a minimum temperature of 25ºC. After that the windows and doors have to be closed and sealed gastight with paper tapes. Before closing the windows, the gas exhaust openings have to be closed. Then a can of Zyklon B is to be opened outside in open air and the content has to be poured at the provided location from the outside into the chamber. The Zyklon B inlet sliding door has to be closed and sealed gas tight with paper tape. The work can only be performed after putting on a gas mask (special filter).

After the chamber is completely closed gastight, the ventilator inside the chamber has to be switched on.

The exposure time of the hydrocyanic acid on the articles to be disinfested has to be 2 hours.

A large sign with the inscription: 'Attention! Danger! Chamber being gassed!' has to be attached at each side of the chamber and in the front room.

After completion of the gassing time, the gas exhaust opening has to be opened from the outside, while the chamber ventilator is switched on. Also, all these tasks are only allowed to be done with the gas mask (special filter) put on.

The exhaust time has to last at least 11/2 to 2 hours.

After 1 hour at the earliest, the gas residue is to be tested at one of the windows. Should this test prove positive, the exhaust time has to be extended. The execution of the gas residue test can only be done with the gas mask on.

After 2 hours at the earliest, depending on the results of the gas residue tests, the articles shall be removed from the chamber. The unloading of the chamber can only be done with gas masks on, even if the gas residue test was negative.

Fumigated pieces of clothes, blankets, etc. can only be used, or taken to the laundry, after being thoroughly aired for at least 6 hours or treated with rug beaters.

It is strictly forbidden to enter gas chambers alone. Everyone who enters a gas chamber has to be observed by at least one other man, so that he can assist in case of an accident.[65] The second, of course, also has to wear a gas mask.

A first-aid kit must always be available and ready to be used. This kit serves exclusively for first-aid in case of accidents in the hydrocyanic acid chamber. It contains, besides the necessary medications, accurate instruction for their use. Everyone who is working with the hydrocyanic acid chamber has to be thoroughly familiar with these directions.

At least twice weekly, the camp medical doctor has to check out the correct operation of the hydrocyanic acid chamber, the age of the special mask filters, and the condition of the first-aid kit.

Operational problems, irregularities, and other occurrences, even of lesser importance, have to be reported immediately to the SS camp physician Mauthausen.

On the fifth of each month the medical camp physician reports:

  • Number and type of fumigations performed in the chamber.
  • Quantity of hydrocyanic acid used.
  • Condition of the first-aid kit and the gas masks.
  • Which SS members were responsible for the individual gassings.
  • Special occurrences.

At least once every two weeks the camp physician has to personally check the fitting of gas masks of all participants. Furthermore, every two weeks he has to inform the operating teams that the usable time of the filter inserts lasts several hours in case there are only minor residues of hydrocyanic gas after the ventilation. Without sufficient ventilation the usable time of the filter inserts (with the gas chamber filled) is only 10 minutes.

The SS camp physician Mauthausen


SS Hauptsturmführer".

4. Gas Residue Test Kit, Gas Residue Test, and the Alleged Homicidal Gas Chambers

The "Service Instruction for the Operation of the Hydrocyanic Acid Fumigation Chamber in the Concentration Camp Gusen" met the civilian standards in all respects. They originated without doubt from a direction by the Office Group DIII (medicine and camp hygiene) of the SS WVHA and are therefore also valid for the Auschwitz camp. The gas chambers inside the fumigation barracks 1 and 2 (buildings 5a and 5b) of Birkenau are the counter-piece of the fumigation chamber of Gusen. SS Hauptsturmführer Eduard Krebsbach, the author of the service direction above quoted, was in Auschwitz in February/March 1943 as a substitute for the SS camp physician SS Hauptsturmführer Eduard Wirth.[66]

According to several representatives of the established historiography, the concentration camp Mauthausen had a homicidal gas chamber that used hydrocyanic acid[67] after autumn 1941. However, this was in reality a circulation type disinfestation chamber.[68] Therefore the comparison between the concentration camps Mauthausen and Auschwitz is perfectly valid, especially if one considers that the Construction Office of Mauthausen was in continuous contact with the Topf company.[69] The claim is ridiculous that the SS Construction Office of Mauthausen would have turned directly to the Topf company for the order of 10 gas residue test kits for the alleged homicidal gas chambers, bypassing the camp physician Krebsbach, whose responsibility it was to store these devices and to supervise the alleged "homicidal gassing," and in the same vein the theory that the Central Construction Office of Auschwitz went directly to the Topf firm with their request to order such gas test kits, bypassing the SS camp physician Wirth, is completely absurd.

But another even more important problem comes up. The gas residue test was, according to the documents, requested for the disinfestation chambers and should therefore logically also be required for the "homicidal gas chambers," assuming that these existed.

Document 2

The danger of poisoning threatened not only the so-called "Sonderkommandos" – that is, the inmates who are said to have carried the corpses out of the homicidal gas chambers – but also the SS men who worked in the crematoria.

Furthermore, inmates also worked in the fumigation chambers, organized in so-called work commandos. If their safety had to be warranted by the service directive quoted above, then the same should also apply to the so-called "Sonderkommandos."

Under these circumstances, a gas residue test would have to be done for each of the alleged homicidal gassings. This procedure would have been a life-saving must for the operators of the alleged gas chambers in the so-called "bunkers" as well as in Crematoria IV and V, because these were not equipped with mechanical ventilation systems. But none of the self-appointed "eyewitnesses" of the "Sonderkommandos" has ever mentioned the gas residue test. The fact that, according to some of these "witnesses," the inmates who were ordered to drag the "gassed" out of the "gas chambers" wore gas masks does not make the gas residue tests superfluous, because according to the "Service Instruction for the Operation of the Hydrocyanic acid Fumigation Chamber in the Concentration Camp Gusen," the fumigation chamber could only be entered "with gas masks on [...] even if the gas residue test was negative." Furthermore, the self-appointed "eyewitnesses" have no knowledge of two further essential facts about the application of Zyklon B. The first point is about the inert Zyklon B carrier granules,[70] which were returned as "used Zyklon" to the Dessau factory, where they were recycled.[71] The "Directives for the Application of Hydrocyanic Acid (Zyklon) for the Fumigation of Vermin (Disinfestation)" mentioned above gave the following instruction about this:[72]

"Remove the used Zyklon remains from the gassed rooms. In general they should be returned to the factory together with the cans and boxes."

The second point refers to the rate of release of hydrocyanic acid from the inert carrier substance. The Soviets made an experiment in the camp Majdanek in August 1944 with two cans of Zyklon B with 1,500 grams content. They opened the cans at an outside temperature of 23 to 28ºC and weighed them after two hours: one then weighed 2,330 grams, the other 2,310 gram.[73] Because the weight of a full can was 3,750 gram, of which 1,500 g was hydrocyanic acid, 1,650 g the inert carrier substance and 600 g the empty can, there was in each can still 80 or 60 g of hydrocyanic acid left over after two hours, which means that within that time interval 95% and 96%, respectively, of the hydrocyanic acid must have evaporated. This corresponds fairly closely to the evaporation tables of hydrocyanic acid from the carrier material Erco, which was published by R. Irmscher in the year 1942.[74]

However, according to the "eyewitnesses" the doors to the "gas chambers" were opened and the corpses removed only a few minutes after the doors had been closed. For example, the self appointed members of the "Sonderkommando" made the following statements about this:

According to Filip Müller, two minutes passed between the closing of the doors and the removal of the corpses;[75] seven minutes according to Charles Sigismund Bendel;[76] seven to eight minutes according to Henryk Mandelbaum;[77] 15 minutes according to Dov Paisikovic;[78] 20 minutes according to Miklos Nyisli.[79]

The service instruction quoted, however, requested a gas residue test after not less than one and a half hours of forced ventilation!

What I want to emphasize is not so much the evident implausibility of a procedure where the allegedly homicidal gas chambers were opened at a time when the hydrocyanic acid was just starting to evaporate, but rather the fact that none of the self-appointed eye-witnesses ever made a comment about this procedure, which would have put the inmates as well as the SS men in immediate danger to life.

Furthermore, not a single "eyewitness" mentioned the use of "special work clothes", although these would have been necessary. As experience has shown, hydrocyanic acid can be absorbed through the skin; the first symptoms of such a poisoning appear "after a stay of 2-5 minutes in an atmosphere with 1 percent of hydrocyanic acid by volume, in spite of good breathing protection."[80] In fact the aforementioned "Directives for the Application of Hydrocyanic acid (Zyklon) for the Fumigation of Vermin (Disinfestation)" also noted the possibility of "Poisoning though the skin."[81]

Furthermore, not a single "eyewitness" mentions the enormous consumption of gas residue tests and special filters, which would have been necessary in view of the claimed mass gassing of people for many years. For example, it is documented that the local administration of the concentration camp Majdanek ordered from the firm Tesch and Stabenow on June 3, 1943, "200 pieces of breathing inserts 'J'" for Zyklon B, which were intended to be used for the disinfestation installations of the camp,[82] and there was undisputedly much less Zyklon used in Majdanek than in Auschwitz!

Finally, not a single eyewitness ever mentioned the first-aid kit or the "kit for life saving injections under the skin," which are mentioned in the direction of March 25, 1931, or the medications contained in this kit, like lobelin and caffein-sodium-benzonate, as well as sodium nitrite and sodium thiosulfate.[83] Especially informative in this connection is the testimony of physician Dr. Miklos Nyiszli, who allegedly belonged to the "Sonderkommando" of Birkenau and therefore must have had regular access to these medications, but did not mention a single word about this. When he came up with the fairy tale about the girl who was miraculously saved after a gassing, he only mentioned briefly a therapy with "three injections," although he was normally not stingy with details.[84] What in the world was injected? Since he, a trained physician(!), believed that Zyklon B was "Chlorine in granular form,"[85] one can easily imagine what kind of "help" he would have administered to SS men or inmates in case of a hydrocyanic acid poisoning: he would have poisoned them point-blank, and the "miraculously saved" girl would have been, in his story, the first victim!

The uniform silence of all "eyewitnesses" about all these aspects of the application of Zyklon B – central and interconnected with each other – leaves only one explanation possible:

None of these "witnesses" had ever attended a homicidal gassing!


RGVA = Rossiiskii Gosudarstvenni Vojennii Archiv (Russian State War Archive), formerly TCIDK: Tsentr Chranenia Istoriko-dokumental'nich Kollektsii (Center for the Preservation of Historical Document Collections), Moscow

APK = State Archive of Kattowice

APMO = Archives of the National Museum of Auschwitz

APMM = Archives of the National Museum of Majdanek


First part first published in German in Vierteljahreshefte für freie Geschichtsforschung 2(1) (1998), pp. 13-22; translated from the Italian by Russ Granata

[1] Challenge at the end of a correction by Faurisson in Le Monde, Feb. 26, 1979; cf. Robert Faurisson, Mémoire en défense – Contre ceux qui m'accusent de falsifier l'Histoire. La question des chambres à gaz. Préface de Noam Chomsky, La Vieille Taupe, Paris 1980, p. 100.
[2] Jean-Claude Pressac, Auschwitz: Technique and Operation of the Gas Chambers, The Beate Klarsfeld Foundation, New York 1989, pp. 431-457.
[3] Cf. R. Faurisson, The Journal of Historical Review, 11 (1) (1991), pp. 25ff.; ibid., 11 (2) (1991), pp. 133ff; Herbert Verbeke (ed.), Auschwitz: Nackte Fakten, Postbus 60, B-2600 Berchem 1, 1996; S. Crowell, "Wartime Germany's Anti-Gas Air Raid Shelters: A Refutation of Pressac's 'Criminal Traces'," The Journal of Historical Review, 18(4) (1999), pp. 7-30.
[4] J.-C. Pressac, Die Krematorien von Auschwitz. Die Technik des Massenmordes, Piper, Munich/Zürich 1994, illustrations, doc. no. 28.
[5] J.-C. Pressac, Auschwitz..., op. cit. (note 2), p. 371.
[6] W. Rademacher, "Der Fall Lüftl, oder: die Justiz zur Zeitgeschichte," in: E. Gauss (ed.), Grundlagen zur Zeitgeschichte, Grabert, Tübingen 1994, pp. 55ff.; Engl: "The Case of Walter Lüftl · Contemporary History and the Justice System," in Germar Rudolf (ed.), Dissecting the Holocaust, 2nd ed., Theses & Dissertations Press, Chicago 2003, pp. 78-80.
[7] C. Mattogno, Auschwitz: The End of a Legend, Institute for Historical Review, Newport Beach, 1994.
[8] R. Butz "Gas Detectors in the Auschwitz Crematorium II";, Apr. 24, 1997.
[9] Mattogno, "Critique of the A.R. Butz' Article 'Gas Detectors in Auschwitz Crematorium II'";
[10] See for this M. Köhler, "Jean-Claude Pressac und die deutsche Öffentlichkeit,", Deutschland in Geschichte und Gegenwart 42(4) (1994), pp. 20-26; dito in: H. Verbeke (ed.), op. cit. (note 3), pp. 19-30; Engl. online:
[11] .J.-C. Pressac, op. cit. (note 4), p. 92.
[12] Jean-Claude Pressac, Les crématoires d'Auschwitz. La machinerie du meurtre de masse. CNSR Editions, Paris 1993, pp. 71f.
[13] J.-C. Pressac, op. cit. (note 4), pp. 92f.
[14] J.-C. Pressac, op. cit. (note 2), p. 72.
[15] J.-C. Pressac, op. cit. (note 2), pp. 218, 223.
[16] J.-C. Pressac, op. cit. (note 4), p. 94.
[17] For the second case see for example the diagram which appears in the article by G. Peters and E. Wünstiger, "Sach-Entlausung in Blausäure-Kammern" in: Zeitschrift für hygienische Zoologie und Schädlingsbekämpfung, Heft 10/11, 1940, p. 193.
[18] Topf letter to Construction Office of Auschwitz dated May 21, 1942. RGVA, 502-1-312, p.63 ("We planned to suck in the fresh air from the floor room, but we consider it more appropriate to take fresh air via the roof and to channel it to the fan through a dedicated duct.")
[19] A. Sieverts, A. Hermsdorf, "Der Nachweis gasförmiger Blausäure in Luft" in: Zeitschrift für angewandte Chemie, 34. Jg., 1921, pp. 4f; F. Puntigam, H. Breymesser, E. Bernfus, "Blausäuregaskammern zur Fleckfieberabwehr. Grundlagen, Planung und Betrieb," Sonderveröffentlichung des Reichsarbeitsblattes. Berlin 1943, pp. 21, 111.
[20] Walter Dötzer, Arbeitsanweisungen für Klinik und Laboratorium des Hygiene-Institutes der Waffen-SS, Berlin, ed. by J. Mrugowsky, Heft 3: Entkeimung, Entseuchung und Entwesung, Urban & Schwarzenberg, Berlin/Vienna 1943, pp. 124f.
[21] APMO, Standort-Befehl, D-Aul-1, p. 46.
[22] RGVA, 502-1-332, p. 108.
[23] TCDIK, 502-1-28, p. 221.
[24] APMO, Standort-Befehl, D-Aul-1, pp. 48-49.
[25] RGVA, 502-1-332, p. 106.
[26] RGVA, 502-1-68, pp. 115-116.
[27] APMO, BW 30/34, p. 48.
[28] Intervista sull'Olocausto. Edizioni di Ar, 1996, p. 42.
[29] Robert Faurisson, "Antwort an Jean-Claude Pressac," in: H. Verbeke (ed.), op. cit (note 3), p. 76.
[30] Letter of February 20, 1943, from Central Construction Office to Kommandantur/Dept. IIIa (inmate deployment): "At Crematory II on Feb. 18, 1942, the commando included only 40 instead of 200 inmates, and on Feb. 19, 1943, only 80 instead of 200 inmates". APMO, BW 30/34, p. 74.
[31] Letter by Police President to Regierungspräsident of Kattowitz dated January 21, 1943, APK, RK 2903, p. 22.
[32] See in this regard my recent study the Central Construction Office der Waffen-SS und Polizei Auschwitz, Edizioni di Ar, 1997; this book will be published in English by Theses & Dissertations Press soon.
[33] APMM, sygn. I d 2, vol.1; cfr. Adela Toniak, Korespondencja w sprawie dostawy gazu cyklonu B do obozu na Majdanku, Zeszyty Majdanka, t.II (1967), pp. 138-170.
[34] Arbeitszeit-Bescheinigung of Messing for the week of 08-14 March 1943. APMO, BW 30/41, p. 28.
[35] J.-C. Pressac, op. cit. (note 4), pp. 94f.
[36] Ibidem, pp. 95f.
[37] See section XII of the "Richtlinien für Anwendung von Blausäure (Zyklon) zur Ungeziefervertilgung (Entwesung)" (Document NI-9912; text in H. Verbeke (ed.), op. cit (note 3), p. 94; Engl. online:
[38] "Runderlaß des Reichsministers für Ernährung und Landwirtschaft und des Reichsministers des Innern" of Nov. 4, 1941, in: Blausäuregaskammern zur Fleckfieberabwehr, p. 111.
[39] Richard Kessler, "Rationelle Wärmewirtschaft in den Krematorien nach Maßgabe der Versuche im Dessauer Krematorium," In: Die Wärmewirtschaft, 4(8) (1927), pp. 137f.
[40] Hans Kraupner, "Neuere Erkenntnisse und Erfahrungen beim Bau von Einäscherungsöfen," special issue of Städtehygiene, 8/1970, p. 4.
[41] RGVA, 502-1-57, p. 306 (memo about some members of the Central Construction Office compiled by Bischoff in January 1943).
[42] Letter from company F. Boos to the Central Construction Office dated June 27, 1942, with subject: "heating plant Auschwitz concentration camp." RGVA, 502-1-138, P.513.
[43] APMO, BW 30/7/34, p. 54.
[44] Testing report of Ing. Prüfer from January 29, 1943, APMO, BW 30/34, p. 101.
[45] RGVA, 502-1-26, p. 61.
[46] "Maschinenfabrik und feuerungstechnisches Baugeschäft." In the thermo-technical area Topf produced: special firing, fully mechanic rosts, semi-mechanic firing, throw fueler "Ballist", special rosting bars, oil firing, preheater, air heater, steam overheater, fly ashes blow-out device, draft enhancing device, industrial chimney construction, crematory facilities. Estimate of Topf from February 29, 1941, RGVA, 502-1-327, p. 195.
[47] The smoke ducts were accessible via appropriate flue entry covers, the chimneys via cleaning doors.
[48] For example, the report by Bischoff dated January 23, 1943, also referring to all four crematoria, was recorded in the registry of BW 30. RGVA, 502-1-313, p. 53.
[49] Except, of course, that it is incomprehensible how a company building crematory ovens for over half a century has to write letters to other companies in order to find out who supplies such gas testers, which were standard equipment for every crematory oven. Editor's remark.
[50] "Une critique sur le fond. Par un abonné de l'Autre histoire," in: L'Autre histoire, no. 6., Oct. 16, 1996, p. 13.
[51] Vierteljahreshefte für freie Geschichtsforschung, 2(1) (1998), pp. 13-22.
[52] Reichsgesetzblatt, 1919, No. 31, S. 165f.
[53] Reichsgesetzblatt, 1927, part I, no. 41, p. 297.
[54] Reichsgesetzblatt, 1931, part I, no. 12, pp. 83f.
[55] Ibid., S. 84.
[56] VMBl., 1931, column 792-796.
[57] Ibid., column 794.
[58] Reichsgesetzblatt, 1932, part I, no. 78, pp. 539f.
[59] F. Puntigam, H. Breymesser, E. Bernfus, Blausäuregaskammern zur Fleckfieberabwehr. Berlin 1943, p. 108.
[60] 1 Vol.% = 12 grams per cubic meter.
[61] 2 Vol.% = 24 grams per cubic meter.
[62] NI-9912.
[63] Ibid., p. 2.
[64] Öffentliches Denkmal und Museum Mauthausen. Archive, M 9a/1; see document 1.
[65] This is the reason why doors to disinfestation chambers are equipped with a peep hole (except for the "standard chambers" working according to the circulation system).
[66] See p. 145 of this issue.
[67] Eugen Kogon, Hermann Langbein, Adalbert Rückerl et al. (ed.), Nationalsozialistische Massentötungen durch Giftgas. Eine Dokumentation, S. Fischer Verlag, Frankfurt/Main 1983, p. 245.
[68] See for this my article "KL Sachsenhausen. Stärkemeldungen und 'Vernichtungsaktionen' 1940-1945," in: Vierteljahreshefte für freie Geschichtsforschung, 7(2) (2003), pp. 173-185.
[69] The correspondence in this matter can be found in the German Bundesarchiv Koblenz, NS4, Ma/54.
[70] Diatomaceous earth in granular form (commercial name: Diagrieß), gypsum ("Erco") or cardboard discs ("Discoids").
[71] Wehrmacht bill of lading to administration of POW Lublin of Feb. 2, 1943, re. shipping of 1,163 kg "used Zyklon" to the Dessauer factory. APMM (Archive of the National Museum Majdanek), sygn. I. d.2, p. 77; see document 2.
[72] NI-9912, p. 4.
[73] J. Graf, C. Mattogno, Concentration Camp Majdanek, Theses & Dissertations Press, Chicago, IL, 2003, pp. 127f.
[74] W. Lambrecht, "Zyklon B – eine Ergänzung," in: Vierteljahreshefte für freie Geschichtsforschung, 1(1) (1997), pp. 1-5. Table on p. 3.
[75] F. Müller, Sonderbehandlung. Drei Jahre in den Krematorien und Gaskammern von Auschwitz, Steinhausen, Munich 1979, p. 215.
[76] "Les crématoires. 'Le Sonderkommando'," in: Témoignages sur Auschwitz, Paris 1946, p. 163.
[77] Höß trial, vol. 26, p. 152.
[78] "Un survivant du Sonderkommando, » in: Auschwitz, Julliard, Paris 1964, p. 161.
[79] M. Nyiszli, Im Jenseits der Menschlichkeit. Ein Gerichtsmediziner in Auschwitz, Dietz, Berlin 1992, p. 36.
[80] H. Betke, "Blausäurevergiftung infolge Aufnahme durch die Haut," in: Zentralblatt für Gewerbehygiene und Unfallverhütung, October 1931, Heft 10, p. 249.
[81] NI-9912, p. 2.
[82] J. Graf, C. Mattogno, op. cit. (note 23), pp. 198.
[83] F. Puntigam, H. Breymesser, E. Bernfus, op. cit. (note 9), pp. 84f.
[84] M. Nyiszli, op. cit. (note 29), p. 79.
[85] M. Nyiszli, Boncolóorvosa voltam az auschwitz-i krematóriumban, Oradea, Nagyvárad, 1946, p. 35. The German translation of this book, as quoted in previous notes, ignores this definition (note 29, p. 36).

Additional information about this document
Property Value
Author(s): Carlo Mattogno
Title: The "Gas Testers" of Auschwitz, Testing for Zyklon B Gas Residues · Documents – Missed and Misunderstood
Sources: published also in "The Revisionist" 2(2) (2004), pp. 140-155
  • Russ Granata: translation
  • Germar Rudolf: introduction
Published: 1998-01-01
First posted on CODOH: July 13, 2012, 7 p.m.
Last revision:
Comments: First part first published in German in "Vierteljahreshefte für freie Geschichtsforschung" 2(1) (1998), pp. 13-22
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