Zyklon B

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Substrate: "Erco cube" Zyklon B
Tin can: Zyklon B

Cyclone B is the name for a 1922 by the company Degesch under the direction of Haber developed biocide , the active ingredient of hydrocyanic acid (chemical hydrogen cyanide Molecular Formula HCN) as the gas from pellets exiting. In humans, this gas is mainly effective through inhalation , in that after a few breaths it stops the body's cells from breathing ( internal suffocation ). Between 1942 and 1944 it was used on a large scale in the Auschwitz-Birkenau extermination camp for industrially organized mass murder ; Camp inmates were also killed with it in several other concentration camps. The name for the poison has become one of the synonyms for the technology and system of the Holocaust .


Zyklon B consisted of liquid hydrogen cyanide, which was dripped onto absorbent carrier materials during production. It was initially used diatomite , this carrier was later replaced by a highly porous gypsum product ("Erco"). A third carrier were pulp disks, so-called discoids. In addition, a chemical stabilizer was added which, because it gassed faster than hydrogen cyanide and irritated the eyes and mucous membranes, also acted as a warning substance and was intended to prevent accidents. In addition, another, slower outgassing warning substance was added. The granulate was delivered in tin cans that could be opened with a special hammer. Oxalic acid and methyl chloroformate were used as stabilizers ; the shelf life was guaranteed for a period of three months after delivery. In practice, Zyklon B could be stored much longer if the cans were protected from moisture and rust. In order to be able to withstand the overpressure of 0.25 to 1  bar inside the cans, they were made of 0.4 mm thick sheet metal and pressure-resistant up to at least 6 bar. The closed cans were tested in the factory and heated to 60 ° C. Zyklon B was delivered in cans of 200 g, 500 g, 1000 g, 1200 g and 1500 g.

The product was sold as a sales brand Zyklon - often without the additional letter B on the label - by two dealers. The additional designations A, B and C were used in the factory to identify different processes, irritant additives and compositions. Zyklon A was introduced in 1920. This mixture of methyl cyanocarbonate and methyl chlorocarbonate was sprayed from large pressure vessels, but was considered unsafe and uneconomical. Zyklon C contained the additive chloropicrin , which attacked uniform buttons, metal buckles, etc. and was therefore unsuitable for disinfesting clothes. The preparation without any warning substance was a special form; this was noted on the label with the designation “Caution, no warning substance”. It was used to treat food and other susceptible substances.

Forms and invoices issued by the specialists commissioned by the sales company Testa for fumigations carried out by them sometimes contained columns with consecutive letters C, D, E and F, through which a specific concentration was officially documented in the fumigation report.

Zyklon B was developed to make it safe to handle hydrogen cyanide. Due to its low boiling point of 25.7 ° C, the cytotoxin hydrogen cyanide is dangerous to handle, especially in liquid form. Hydrocyanic acid has a high vapor pressure even at room temperature and is accordingly highly volatile . Furthermore, hydrocyanic acid forms explosive mixtures with air in concentrations above 5.6%. The slower outgassing when using Zyklon B largely prevents the sudden build-up of high (explosive) concentrations. Significantly lower concentrations are sufficient for pest control in ships and silos; in practice, concentrations of approx. 0.03% are used. Zyklon B is easy to transport thanks to its binding to a substrate (Erco cube, discoids), stabilization through chemical additives and the packaging.

If Zyklon B is used properly as a pesticide, accidents are extremely rare. Accidents such as explosions and poisoning with hydrogen cyanide are often due to other products such as B. cyanide , liquid hydrogen cyanide or other chemical accidents. Only one accident is known when Zyklon B was used by the Wehrmacht and when it was used as intended for disinfestation (e.g. clothing) in the concentration camps, although several hundred tons of Zyklon B were used during this time.


Information and warning point Zyklon B at the former sugar refinery in Dessau

Walter Heerdt's invention of the process for absorbing hydrogen cyanide in kieselguhr made it possible to produce an efficient and safe pest control agent. This process was applied for a patent on June 20, 1922 by the German Society for Pest Control mbH (Degesch for short) under number DE 438818, which was granted by the Reich Patent Office on December 27, 1926.

The active ingredient was produced by the Dessauer Werken für Zucker-Raffinerie GmbH and from 1935 also by the Kaliwerke AG in Kolín, Czech Republic, on behalf of Degesch, a subsidiary of Degussa , the IG Farben Group and Th. Goldschmidt . Zyklon B was sold by the trading companies Tesch & Stabenow (Testa) and Heerdt-Lingler (HeLi).

Degesch's annual reports show annual production quantities between 160 tons and 411 tons for the period from 1938 to 1943. In 1943, the price for armaments contracts was reduced to 4.55 Reichsmarks per kg. Dessau was bombed at the end of May 1944 and the factory was so badly damaged that annual production fell to 231 tons. During the heavy British air raid on Dessau on March 7, 1945, the factory and warehouse were completely destroyed.

In the GDR , from 1952 to 1969, Zyklon B was manufactured as a disinfestation agent by VEB Gärtschemie Dessau, the successor to Dessauer Werke für Zucker-Raffinerie GmbH, and sold under the name Cyanol . In addition to the location of the former production facility, an information and warning point was opened at the brewery bridge in Dessau-Roßlau on January 27, 2005 on the occasion of the 60th anniversary of the liberation of the Auschwitz extermination camp . After 1969, Zyklon B was manufactured in Schwedt .

In the Federal Republic of Germany it was sold after 1945 under the name Cyanosil and Zedesa hydrogen cyanide in Germany and under the name Zyklon abroad. The manufacturer was the German Society for Pest Control mbH, Detia Freyberg GmbH and Desinsekta GmbH. The approval for this product expired in 2001. The production of Zyklon B was continued under a changed brand name as Uragan D2 in the Czech Republic (Lučební závody Draslovka, as , Kolín ). The product consists of at least 97.6% anhydrous hydrogen cyanide, which is stabilized by adding 0.1% phosphoric acid and 1.0% sulfur dioxide . It is filled in pure liquid form in stainless steel pressurized gas bottles weighing 27.5 kg, as well as, analogous to the product cyclone discoids, weighing 1500 grams in hermetically sealed stainless steel cans , adsorbed on pulp discs . The agent is approved under the trade names Uragan D2 , Bluefume and Cyanopur in several EU countries as a fumigant to combat wood-destroying insects in wood and hygiene pests (insects and rodents) in empty objects and means of transport.

Use in industry

Zyklon B was mainly used as a vermin exterminator for the fumigation of ships, cold stores and grain mills, as well as the disinfestation of mass accommodation and the delousing of clothing. After 1939, the need rose sharply due to the deployment in the Wehrmacht and in camp accommodation for forced and foreign laborers . According to Detia-Degesch, hydrogen cyanide was still used in 2010 in South Korea for fumigation of fruit under the trade name Cyanosil . In Germany, Cyanosil and the related crop protection agent Zedesa hydrocyanic acid are no longer used. The approval by the Federal Office for Consumer Protection and Food Safety expired on December 31, 2001.

Use in concentration camps

In the Auschwitz-Birkenau concentration camp , Zyklon B was used from the spring of 1942 to murder camp inmates and newcomers from the ghettos en masse and on an industrial scale in gas chambers disguised as shower rooms . It is "not excluded" that independently of this, Zyklon B had been used to kill the mentally ill at Fort VII in Posen at the end of 1939 in order to test the effect of the poison gas on them (see also First Gas Chamber in Posen ).

In autumn 1941 SS-Hauptsturmführer Karl Fritzsch had 600 Soviet prisoners of war and 250 sick prisoners gassed with Zyklon B in the basement of Block 11 of the Auschwitz I main camp . The camp commandant Rudolf Höß then decided to only use this poison gas because he considered it “more effective” against engine exhaust and carbon monoxide from gas cylinders. Zyklon B was also used - to a much lesser extent - to kill people in the Majdanek , Mauthausen , Sachsenhausen , Ravensbrück , Stutthof and Neuengamme camps . In most of the extermination camps , engine exhaust, sometimes pure carbon monoxide, was used for this purpose.

Zyklon B label (April 1946)

In experiments with poison gases in the Croatian concentration camp Stara Gradiska were conducted also Zyklon B was used.

From 1979 to 1985, Jean-Claude Pressac conducted detailed research into the use of Zyklon B in the Auschwitz-Birkenau extermination camp. He found:

  • Zyklon B was needed in large quantities for disinfestation by the Wehrmacht and in the concentration camps .
  • By far the largest part of Zyklon B that reached Auschwitz was actually used there as intended for vermin disinfestation in order to kill lice as a carrier of epidemics.
  • However, a small percentage of the delivered Zyklon B was sufficient to carry out the mass murder of people: even a low dose of hydrogen cyanide is fatal to warm-blooded living beings (1/22 the dose for invertebrates ). In the trial against the managing director of Degesch, Gerhard Peters , it was found that four kilograms of Zyklon B were sufficient to gas 1000 people.

Due to the war-related shortage, the proportion of warning and irritant substances in Zyklon B was reduced; from June 1944 the addition was dropped entirely. As early as June 1943 there were deliveries of Zyklon B without warning material to Auschwitz. According to the reasons for the verdict in the trial against the managing director of Degesch / HeLi ( Heerdt- Lingler), it has been proven that this special form was used there to kill people.

Criminal prosecution

In obtaining the Auschwitz concentration camp was hauptsturmführer Robert Mulka active, who also victims in the gas chambers and among other reasons at the Frankfurt Auschwitz Trial was sentenced. Those responsible for the delivery companies Degesch (German Society for Pest Control), HeLi (Heerdt-Lingler) and Testa (Tesch & Stabenow) were also on trial. Bruno Tesch and his managing director Karl Weinbacher were sentenced to death and executed by the British military justice in the Testa trial . Gerhard Peters von der Degesch was initially sentenced to six years ' imprisonment, but after serving in part , he was acquitted in the retrial in 1955, eight years before the start of the Auschwitz trials.


  • Günter Morsch , Bertrand Perz: New studies on National Socialist mass killings by poison gas. Metropol, Berlin 2011, ISBN 978-3-940938-99-2 .
  • Gerhard Peters: Hydrocyanic acid for pest control. Ferdinand Enke publishing house, Stuttgart 1933.
  • Jean-Claude Pressac : Auschwitz. Technique and operation of the Gas Chambers. (Beate Klarsfeld Foundation) New York 1989 - online .
  • Jean-Claude Pressac: The Auschwitz Crematoria: The Technique of Mass Murder. Piper Verlag, new edition Munich 1995, ISBN 3-492-12193-4 .
  • Jürgen Kalthoff, Martin Werner: The dealers of the Zyklon B: Tesch & Stabenow. A company history between Hamburg and Auschwitz. VSA-Verlag, Hamburg 1998, ISBN 3-87975-713-5 ( offenes-archiv.de [PDF]).
  • Gerhard Peters: Hydrocyanic acid for pest control . Enke-Verlag, Frankfurt a. M. 1933 ( archive.org ).

Web links

Commons : Zyklon B  - album with pictures, videos and audio files

Individual evidence

  1. Achim Trunk: The deadly gases . In: Günter Morsch u. Bertrand Persch: New studies on National Socialist mass killings by poison gas . Berlin 2011, p. 37f.
  2. Jürgen Kalthoff, Martin Werner: The dealers of the Zyklon B. Tesch & Stabenow. A company history between Hamburg and Auschwitz. Hamburg 1998, ISBN 3-87975-713-5 , p. 127.
  3. ^ Kalthoff / Werner: The dealers of the Zyklon B. Tesch & Stabenow. A company history between Hamburg and Auschwitz. Hamburg 1998, ISBN 3-87975-713-5 , pp. 29/30.
  4. So at Kalthoff / Werner: The dealers of Zyklon B. Tesch & Stabenow. A company history between Hamburg and Auschwitz. Hamburg 1998, ISBN 3-87975-713-5 , fig. P. 59 / p. 241. Erroneous in Raul Hilberg: The annihilation of European Jews, Vol. 2, Frankfurt Fischer Verlag, 1994, p. 952.
  5. Results of the research group Zyklon B / Dessau ( Memento from June 24, 2009 in the Internet Archive )
  6. Patent DE438818 : Method for pest control. Registered on June 20, 1922 , published on December 27, 1926 , applicant: Degesch, inventor: Walter Heerdt.
  7. ^ Kalthoff / Werner: The dealers of the Zyklon B. Tesch & Stabenow. A company history between Hamburg and Auschwitz. Hamburg 1998, ISBN 3-87975-713-5 , pp. 120, 126, 151, 218.
  8. ^ Kalthoff / Werner: The dealers of the Zyklon B. Tesch & Stabenow. A company history between Hamburg and Auschwitz. Hamburg 1998, ISBN 3-87975-713-5 , p. 124.
  9. Holger Beisitzer: Zyklon-B.info ( Memento from January 17, 2010 in the Internet Archive )
  10. Bundesinstitut BgVV (2000) (PDF; 269 kB) Accessed March 7, 2007.
  11. Cyanosil plant protection product. In: proplanta.de. Retrieved June 15, 2018 .
  12. Website of the manufacturer Lučební závody Draslovka as ( Memento of December 9, 2013 in the Internet Archive )
  13. ^ Dlouhý M., Aulický R., Lišková J., Šimbera J., Stejskal V .: Metodika bezpečné aplikace pomocí nové komory a formulace HCN ochrany osiv a rostlinných materiálů proti skladištním broukům a zavíječtům. P. 75 (Czech). In: Stejskal V., Frýdová B. (eds.): Sborník ze semináře a workshopu VVFaŽP: Nové metody a přístupy k řízení rizik regulovaných škůdců v ČR a legislativníproblemémy použití biocidu. Výzkumný ústav rostlinné výroby. Retrieved November 25, 2019 .
  14. DE-0010212-0000 BLUEFUME. Summary of the properties of a biocidal product. S. 6. In: European Chemicals Agency. Retrieved November 25, 2019 .
  15. Biocidal product factsheet. Authorization details. In: European Chemicals Agency. Retrieved November 25, 2019 .
  16. ^ Joachim Jeltsch: Marketing News. (PDF) Fruit fumigation with Cyanosil. (No longer available online.) DETIA DEGESCH GMBH, 2010, p. 6 , archived from the original on March 28, 2016 ; accessed on March 28, 2016 .
  17. Federal Office for Consumer Protection and Food Safety: Managing Risks - Protecting Consumers. (XLS) Expired crop protection products. 2017, accessed June 16, 2017 .
  18. ^ Michael Alberti: The persecution and extermination of the Jews in Reichsgau Wartheland 1939-1945. Wiesbaden 2006, ISBN 3-447-05167-1 , p. 326.
  19. The exact date is disputed. Usually a day is mentioned in the period from August 31 to September 5, 1941; Pressac even accepts in early December. See Robert Jan van Pelt: Auschwitz. In: Günther Morsch, Bertrand Perz: New studies on National Socialist mass killings by poison gas. Berlin 2011, ISBN 978-3-940938-99-2 , pp. 201–203 with note 14.
  20. Alexander Ruoff: Zyklon B , Encyclopedia of National Socialism, edited by Wolfgang Benz, Hermann Graml and Hermann Weiß, Klett-Cotta, Stuttgart 1998, p. 815; Quote: "Effective" is historically contemporary and comes from Rudolf Höß.
  21. Michele Frucht Levy: "The Last Bullet for the Last Serb" - The Ustasa Genocide against Serbs 1941-1945. In: David M. Crowe (Ed.): Crimes of State Past and Present. Routledge 2011, ISBN 978-0-415-57788-5 , p. 71. [1]
  22. Fritz Bauer (edit.): Justiz und NS-Verbrechen - Collection of German criminal judgments for National Socialist homicides , Amsterdam 1975, vol. XIII, ISBN 90-6042-013-6 , case no. 415, p. 167: "6 kg for 1500 people "/ Jörg Friedrich: The cold amnesty. Frankfurt am Main 1984, ISBN 3-596-24308-4 , p. 207.
  23. Kalthoff / Werner: The dealers of the Zyklon B. P. 180.
  24. Christiaan F. Rüter (Ed.): Justiz und NS-Verbrechen - Collection of German criminal judgments for National Socialist homicides 1945 - 2012. Amsterdam 1975, Volume XIII, pp. 130–225, here p. 162 Procedure No. 415 ( Memento des Originals dated May 26, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. : The judgments against the suppliers of the Zyklon B. @1@ 2Template: Webachiv / IABot / www1.jur.uva.nl