The Nizkor Project: Remembering the Holocaust (Shoah)

Shofar FTP Archive File: camps/auschwitz/cyanide/cyanide.001

Newsgroups: alt.revisionism
Subject: Cyanide, Zyklon-B & Mass Murder

Archive/File: camps/auschwitz/cyanide cyanide.001
Last-Modified: 1994/10/03
From: Raskolnikov 

                Cyanide, Zyklon-B, and Mass Murder

                       Brian Harmon

I. Introduction

    Because many holocaust deniers find themselves unable to 
dismiss the many volumes of historical information documenting 
the Holocaust, they often turn to other methods.  A very 
common tactic is to claim that the Holocaust was "technically  
impossible", improperly citing chemical and physical data as 
"proof".  The most well known example is the "Leuchter Report" 
where Fred Leuchter, a self-proclaimed engineer, claimed that 
"no one was gassed at Auschwitz", using a combination of poor 
chemical analysis and technical difficulties as "proof".  
Another example, "The Luftl Report", written by the Austrian 
Walter Luftl, erroneously claims that not enough people could 
be crammed into the chambers, and that Zyklon was too 
dangerous to use for extermination.  Many of these documents 
are shrouded in pseudo-scholarly terminology and methodology, 
and use confusing statements to make their lies seem more 
tenable.  The deniers hope to play on the common individual's 
lack of knowledge in chemistry and physiology to confuse and 
obfuscate the issue.  

    I will not deal directly with the claims of Leuchter and 
Luftl here, rather I hope to provide the knowledge necessary 
to take on Holocaust denier's claims directly, so they can 
easily be discredited by anyone. As I hope to show, a little 
knowledge of physiology and chemistry is all that is required 
to see through their fabrications. 

    In this paper, I will discuss how cells make and use 
energy via aerobic metabolism.  Then, I will show exactly how 
cyanide kills by shutting down aerobic (oxygen-using) 
metabolism in organisms, including how much cyanide can kill, 
and why warm blooded mammals are the most susceptible to 
cyanide poisoning.  The supporting biochemical and 
toxicological data will set the context for the next section, 
which discusses how the gassing of people could be carried 
out.  I will extrapolate from the Degesch manual on Zyklon B 
to show that Zyklon cloud be used quite easily in a number of 
situations, even at very low temperatures. I will then present 
a "hypothetical gassing", where I will run some basic 
calculations showing how easily a large number of people 
(about 1.8 million) could be killed in one and one half years 
with only one gassing a day.  Comparing this with documents on 
how the camps actually were run, It should be self-evident 
that gassings with cyanide were quite easy for the Nazis to 
carry out. 

    This document may be of a somewhat technical and 
detailed nature.  It is also exceptionally long, much longer 
than I had anticipated.  To remedy this, I also will write a 
shorter "reference sheet"  that takes the major conclusions 
and points of this paper without all of the laborious 
calculations and explanations.  I intended this document 
primarily as a reference resource rather than a document to be 
completely absorbed at one sitting.  

II. Structure of the Paper

Part one:  Physiological Basis of Cyanide Poisoning
        A. Cells and energy     
                -- How cells use energy         
                -- How the electron transport system works
                -- How oxidative phosphorylation provides energy 
        B. Cytochromes in the Electron Transport System
                -- Different cytochromes, and hemoglobin
        B. How Cyanide Kills
                -- Poisoning the ETS  
                -- Hemoglobin
        D. Data on Cyanide 
Part Two:  Use of Zyklon B
        A. Extrapolate from Nuremburg doc N1-9912
        B. A Hypothetical Gassing
        C. Compare to Existing Documents

A Brief Aside:  What is Cyanide?

    Cyanide refers to a large number of compounds that 
contain the negatively charged cyanide ion:  CN-.  This ion 
consists of one carbon atom triple-bonded to one nitrogen 
atom. The negative charge primarily rests on the carbon atom.  
Cyanide can be found both as a gas and as a salt.  When bound 
to hydrogen, it's referred to as hydrogen cyanide (HCN), and 
is a gas at room temperature.  When bound to ions like sodium 
(Na+) or Potassium (K+), it's a salt and is a water soluble 
solid. Its name varies depending on the ion it binds. KCN is 
potassium cyanide, for example.

    More information is presented in the "Data on Cyanide" 
section (see below).

Part One: The Physiological Basis of Cyanide Poisoning

  A. Cells and Energy {1}.  

    Cells need energy to grow and maintain their function. 
In cells, energy is carried in the form of a transport 
molecule, namely Adenosine Triphosphate (ATP).  The metabolism 
of molecules such as glucose (sugar), lipids (fats), etc. 
release energy that is used to make more ATP.  ATP is  
essentially an "energy carrier" that allows cells to utilize 
energy derived from food.  Without ATP, a cell will die, as 
will the organism itself.  If a chemical interrupts a cell's 
ATP producing machinery, that cell will die once it runs out 
of ATP.  Cyanide eliminates a cell's ability to produce ATP.  
Before we can discuss how this happens, we must first deal 
with how cells produce ATP under normal conditions.

    Almost all ATP is produced in the mitochondria, a small 
cellular organelle (literally "small organ").  The 
mitochondria are, in essence, the "power plants" of a cell.  A 
mitochondrion has two membranes, an inner one and and outer 
one.  The outer membrane is highly permeable, and it will 
allow just about anything through.  The inner membrane, on the 
other hand, is very impermeable.   Only carbon dioxide (CO2), 
water (H2O) and oxygen (O2) can pass through this membrane 
without transport proteins to carry them across{2}.  The 
impermeable nature of the inner mitochondrial membrane (IMM) 
will be important later.  

    Cells produce ATP through a combination of the electron 
transport system (ETS) and oxidative phosphorylation (OP), 
both in the mitochondrial inner membrane.  The electron 
transport system can be compared to an electric motor, where 
current supplied to the motor allows work to be done.  The 
current passing through an electric motor is just a stream of 
electrons, and the "current" passing through the ETS is no 
different.  High energy molecules generated by metabolism like 
NADH and FADH2 supply the ETS with electrons, just as a 
battery would supply a motor with current.  This current 
allows the ETS to do work.  The "work" done is the pumping of 
positively charged hydrogen atoms (protons, H+) across the 
inner mitochondrial membrane.  As I stated earlier, this 
membrane will not allow anything back across without help from 
a transport protein.  At the end of the ETS, electrons have to 
"go somewhere" to keep the current flowing -- they must leave 
the ETS.  In a battery, electrons go to the positive pole.  In 
the ETS, electrons are dumped onto oxygen, in effect acting 
like an electron "sink".  This is where oxygen is used in 
metabolism, and will be dealt with later.  

    After a certain time, a significant number of protons 
will be pumped out of the inner mitochondria, with many more 
protons outside the mitochondria than inside.  As the protons 
are positively charged, the area outside the mitochondria will 
have a relative positive charge, and the inside will have a 
relative negative charge.  There now exists a net potential 
across the membrane, much like a fully charged battery. This 
potential can be relieved to do work, namely the synthesis of 

    The positive charges outside the mitochondria will 
"want" to flow back in for two reasons: (1) the electrical 
potential between the inner mitochondrial membrane and the 
outer mitochondria. The positively charged H+ ions (protons) 
will flow, if allowed, into the more negatively charged inner 
mitochondria.  This is much like how a battery works, but in 
reverse.  (2) The chemical gradient across the membrane.  
Simply by random motions, molecules will flow from areas of 
high concentration (outside the mitochondria) to those of low 
concentration (inside the mitochondria).  This is the same 
reason a drop of dye in water will spread out over time even 
if undisturbed.  If molecules are prevented from diffusing by 
a barrier (the inner membrane), a net pressure will result 
from their impacts on the membrane, called the osmotic 
pressure. The combination of electrical potential and osmotic 
pressure is what provides the energy to make ATP in a cell 

    Oxidative phosphorylation (making ATP) requires a 
membrane-bound protein enzyme called ATP synthetase {4}.  ATP 
synthetase allows H+ ions back across the membrane, relieving 
the pressure like letting air out a balloon.  This flow of 
protons allows the enzyme to combine Adenosine Diphosphate 
(low E) and inorganic phosphate to make ATP (high energy). 
This type of ATP synthesis is called oxidative 
phosphorylation.  It takes about two or three protons moving 
through the enzyme to make one ATP molecule.  The enzyme 
requires a proton gradient across the membrane, with a higher 
concentration on the outside than the inside.  If anything 
prevents the electron transport system from setting up this 
proton gradient, ATP synthesis will not occur and the cell 
will die.

-- Cyanide Poisoning

    At the very end of the ETS, four electrons are added to 
an oxygen molecule (see above).  These electrons are added to 
an oxygen molecule (O2), which combines with protons to make 2 
water molecules.  The ETS must dump electrons onto oxygen just 
to keep the steady flow of electrons going, otherwise 
electrons will "back up" and the current will stop.  
Metabolism has an absolute requirement for oxygen, and it will 
stop without it.  If the ETS stops, the proton gradient will 
fade away, ATP synthesis will stop, and the cell with die.  
This last step, where electrons are given to oxygen to make 
water, is where our cells utilize oxygen in metabolism.  
Cyanide prevents the transfer of electrons to oxygen from the 
last protein in the electron transport system, called a 

    Cyanide reaches cells primarily through the blood, and 
readily diffuses across the lungs during normal breathing.  
Ingestion with food or drink is also lethal, as cyanide will 
diffuse across the stomach wall and small intestine. Cyanide 
will also very slowly diffuse across the skin, but this can 
take over an hour {5}.  Therefore cyanide intake through the 
lungs and digestive tract is a very significant source of 
poisoning, but very little occurs from absorption through the 

  B. Cytochromes in the ETS
    Electrons passing through ETS are carried by three types 
of molecules:  iron-sulfur proteins, ubiquinone, and 
cytochromes {6}.  When talking about cyanide poisoning, the 
cytochromes are the most important.  Cytochromes contain a 
very important structure called a porphyrin ring, which is an 
aromatic, planar carbon-based ring with an iron atom 
conjugated in the middle.  A similar porphyrin ring structure 
is also the oxygen binding structure in hemoglobin, a 
vertebrate oxygen carrier protein in the blood.  The iron has 
two oxidation, or "charge" states, +2 (when it holds and 
electron) and +3 (when it doesn't).  The iron atom holds one 
electron at a time, and passes it on the next molecule in the 

    The iron atom, in addition to being bound by the 
porphyrin ring, is often conjugated by the amino acids 
histidine or cysteine.  As the ring structure is planar, there 
are two faces that can be conjugated by amino acids:
                ---- Fe(+3)--   Porphyrin molecule (side view)

    Some cytochromes, however, are open on one of their two 
        --- Fe(+3)---

    This open face is where hemoglobin in the blood cells 
and a specific cytochrome in the ETS (Cytochrome a3, to be 
exact) bind oxygen.  Cytochrome a3 is the terminal cytochrome 
that passes on electrons to oxygen to make water:

         O2  +  (2)H2  +  4 electrons ---->  (2)H20

        Cyt a3 binds oxygen at its open face {7}:

        ---- Fe(+2)--

    When all works well, cytochrome a3 passes electrons to 
oxygen, producing water. Dumping electrons onto oxygen acts as 
a "sink" which allows electrons to flow continuously through 
the ETS.  The only problem is, certain poisons bind to this 
cytochrome more strongly than oxygen, specifically cyanide and 
carbon monoxide {8}.

  C. How Cyanide Kills

-- Poisoning the ETS

    Cyanide binds cytochromes much in the same way that 
oxygen does, by conjugating at its open site.  Unlike oxygen, 
cyanide cannot receive electrons from cytochrome a3.  
        -:C=N: (note - actually a triple bond between C and N)

    With the ETS deprived of its electron "sink", the whole 
system backs up.  Without the ETS, oxidative phosphorylation 
will dissipate the H+ gradient, ATP synthesis will stop, and 
the cell will die.  Cyanide binds cytochromes more tightly 
than oxygen, and as a result is lethal at very low 
concentrations, at about 300 ppm.  The effect also occurs at 
hemoglobin, as cyanide will bind to that too, preventing 
oxygen from reaching cells.  In essence, this is how cyanide 
kills cells and whole organisms.

-- Hemoglobin

   Cyanide is most effective on warmblooded animals such as 
mammals, but is less effective on insects.  While insect 
mitochondria and vertebrate mitochondria are not radically 
different, one thing is: Hemoglobin.  Vertebrates carry oxygen 
in their blood via hemoglobin, while insects do not carry 
oxygen in their blood at all.  Instead, insects have air 
tubules that carry oxygen directly to all cells in their body.  
Because cyanide poisons hemoglobin too, animals that use it 
are all the more susceptible. Also (while I am not sure of 
this) insects may be more tolerant of anaerobic metabolism 
than vertebrates.       

   Since cyanide binds to hemoglobin much in the same fashion 
as it binds cytochrome a3, cyanide takes hemoglobin out of 
commission as well {9}.  With their oxygen carrying molecules 
bound by cyanide, vertebrates die all the faster from 
asphyxiation.  Mammals are also very dependent on oxygen-
utilizing metabolism, and will die in minutes if it is shut 
off.  Insects, lacking hemoglobin, die more slowly as their 
cells must be starved of ATP. Insects may also be able to 
survive longer on anaerobic (non-O2 utilizing) metabolism.

    Cyanide kills by binding to cytochrome a3 in the electron 
transport system.  As this site is usually bound by oxygen, 
the passage of electrons from the ETS to oxygen is prevented, 
backing up the system.  Unable to maintain a proton gradient 
without a properly functioning ETS, ATP synthesis stops and 
the cell dies.  In vertebrate organisms, cyanide also binds to 
the porphyrin ring in hemoglobin, exacerbating cyanide's toxic 

 D. Data on Hydrogen Cyanide:

    Here's what the 10th edition (1983) of the Merck Index had 
to say on Hydrogen Cyanide:

HYDROGEN CYANIDE: Hydrocyanic acid, Blauseare, prussic acid. 
[preparation info deleted] Colorless gas or liquid; 
characteristic odor; very weakly acidic; burns in air with a 
        Gas density:  0.941 (air = 1)
        Liquid density: 0.687 [g/cm^3, I assume]
        melting point: -13.4 deg Celsius
        Boiling Point: 25.6 deg Celsius
    The LC50 (lethal dose for 50% of animals) in rats -- 544 
ppm (5min), mice 169 ppm (30 min), dogs 300 ppm (3 min).  
HUMAN TOXICITY:  [..] exposure to 150 ppm for 1/2 to 1 hour 
may endanger life.  Death may result from a few min. exposure 
to 300 ppm.  Average fatal dose: 50 to 60 milligrams. 
    USE:  The compressed gas is used for exterminating rodents 
and insects in ships and for killing insects on trees, etc.  

Here's what _Chemistry of Industrial Toxicology_ had to say 
about it (p94) [added emphasis is mine]:

    "Hydrogen cyanide, or hydrocyanic or prussic acid, owes 
its toxicity not to its acidity but to the cyanide ion (CN-). 
Thus the soluble cyanides-- sodium, potassium,etc. -- are 
equally toxic in the same molar concentrations.  Unlike carbon 
monoxide, hydrogen cyanide is a protoplasmic poison, killing 
insects and other lower [sic] forms of animal life.  _It does 
not kill bacteria, however_.                          ^^^^^^^
^^^^^^^^^^^^ ^^^^^^^^^^^^^^
Hydrogen cyanide acts by inhibiting tissue oxidation, that is, 
by preventing useful employment of oxygen carried by the 

    Cyanides are very rapid in their effects, killing 
instantly if present in sufficient amounts.  It is this speed 
of action, rather than the minuteness of the fatal dose, which 
accounts for the reputation of cyanide as the most powerful 
common poison [..]

    Hydrogen cyanide is used as a fumigant in dwellings, 
warehouses, and ships. _Although such fumigations are 
potentially very dangerous, accidents can be avoided by proper 

In high concentrations, hydrogen cyanide is absorbed through 
the skin; therefore complete reliance cannot be placed on a 
gas mask. After 1 hour exposure, 100 to 250 ppm of HCN are 
[assumed the 100-250 ppm value is for absorption through skin]

        Some things I'd like to point out:

    Cyanide will not kill bacteria, and is completely useless 
for disinfecting a morgue or hospital.  Its only medical use 
is to kill vermin (rats, mice, lice) that may harbor 
pathogens.  Some Holocaust deniers claim that cyanide was used 
to disinfect "morgues" in Auschwitz.  This is clearly a 
ludicrous notion.

    The sources I listed make specific references to HCN's 
widespread use as a fumigant, and that it can be done easily 
with the right precautions.

Major Modes of Poisoning  

    HCN will pass through the skin, and poisoning can result.  
Absorption through the skin is a much slower process than 
through lungs, so a short exposure to skin is not very 
dangerous.   It also takes a higher concentration of the gas 
{10}. Absorption of cyanide through the skin is not 
significant unless the concentration is high over a long 

    According to July 1993 issue of _American Family 
Physician_, cyanide poisoning through the skin is very rare:  
"   Cyanide is absorbed through the lungs, gastrointestinal 
tract, and skin.  Symptoms can occur within seconds of HCN 
[cyanide gas] inhalation; ....Cyanide is readily absorbed 
through the mucous membranes and the eyes.  Clinical cases of 
cyanide poisoning after dermal exposure are rare and most 
often have involved burns with molten cyanide salts or 
immersion in cyanide solutions." 
    Cyanide poisoning through the skin is therefore not a 
significant mode of poisoning unless you have very high 
concentrations over a very long period of time.  

PART TWO: The Use of Zyklon B

A) Nuremburg Document #NI-9912:  The Degesch Manual

    As mentioned above in the technical data section, hydrogen 
cyanide is often used as a fumigant for ships, warehouses, and 
dwellings.  Cyanide can be used to kill vermin and insects, 
but it will not kill bacteria {11}.  It is therefore useless 
for disinfecting anything, but it will eliminate vermin that 
harbor pathogens.   

    For fumigation purposes, a German firm called Degesch made 
a product called Zyklon B.  Zyklon B consisted of liquid HCN 
adsorbed onto a carrier -- "wood fiber disks, dia gravel, or 
small blue cubes [sic]" {12}.  Although toxic, cyanide was 
hard to detect alone, so an irritant was added to the Zyklon 
to warn people of exposure.  

    A "typical" can of Zyklon contained 200 grams of HCN 
adsorbed onto the carrier, and was stored in metal tins marked 
with a death's head and warning that read: "Giftgas!" (Deathly 
poisonous gas!) {13}.  Zyklon-B shipments to Nazi Death camps 
had the warning indicator removed, which would prevent people 
from detecting the gas's presence before it was too late {14}.
    The original Degesch set of instructions on using Zyklon-B 
for fumigation discuss the various precautions that must be 
taken, and under what conditions could Zyklon B be used.  The 
primary means of protection was a gas mask, and many different 
structures and temperatures pose no problem for fumigation.  
The Degesch manual is also known as Nuremburg document NI-
9912.  Information is taken from the English translation, but 
I have checked most of the quotes and information with the 
original German (I speak a little, and read a bit more).  I 
won't quote the whole thing here, but I want to point out some 
noteworthy items {15}:

1) Properties of Prussic Acid [HCN, cyanide]:  

    "Prussic acid is a gas which is generated by 
evaporation... the liquid evaporates easily."  
    "Danger of explosion:  75 grams of HCN in 1 cubic meter of 
air.  Normal application approx. 8-10 g per cubic meter, 
therefore not explosive"
    " mg per kg of body weight is sufficient to kill a 
human being..."

2) Protection against gas.
    "Each member must at all times carry with him:
        1. his own gas mask
        2. at least 2 special filter inserts against Zyklon 
      Prussic acid [for use in gas mask]
        3. The leaflet 'First aid for prussic acid poisoning'
        4. work order
        5. Authorization certificate
Each disinfestation[sic] squad must at all times carry:
        1. at least 3 special inserts as extra stock.
        2. one gas detector
        3. 1 instrument for injecting Lobelin. 
        4. Cardiazol, Voriazol tablets 
        5. 1 lever or pickhammer for opening cans of Zyklon
        [etc.. warning signs, material to reseal cans]"

    NOTE: No measure of personal protection other than a gas 
mask, special filter, a gas detector, and antidote drugs are 
mentioned.  No precautions are taken to prevent HCN from 
seeping through the skin.  One can only assume that there 
wouldn't be a high enough concentration of gas or there 
wouldn't be enough time for the gas to seep in.  Therefore, a 
gas mask with special filters alone would be sufficient to 
protect a user against the gas.  

3) Buildings to be fumigated:

    A wide variety of structures are mentioned, with all types 
of contents.  Detailed descriptions are given on how to handle 
pets, bedding, clothing, and other domestic items inside of a 
building to be fumigated.  Also, recommendations for sealing 
and ventilating various building types are given.  Form these 
instructions, it is clear that Zyklon-B was used to fumigate 
any number of buildings, including residential dwellings.  
Buildings did not have to be designed specifically for 
Zyklon's use.  

4) Working Temperature:
    The instructions discuss using Zyklon at low temperatures, 
even below five degrees Celsius.  To fumigate a building, it 
will take 8g of prussic acid per cubic meter for 16 hours at 
temperatures above five degrees Celsius.  Even warmer 
temperatures need only 6 hours fumigation time.  If the 
temperature is below five degrees Celsius, the fumigation time 
is to be extended to 32 hours.  

    These times are for flies, lice, fleas, etc. with eggs, 
larvae and chrysalises.  I can only guess it would take less 
time for warm blooded mammals like rats and mice, unless the 
"etc." refers to them as well.

   Since Zyklon can be effectively used at temperatures close 
to freezing, it seems that even cold temperatures did not 
prevent the use of Zyklon as fumigant (or the case of the 
Holocaust, as a murder weapon).

    Let me summarize the points taken from the Degesch 
documents: (1) the HCN liquid evaporates easily, and is highly 
toxic; (2) normal working concentrations are well below (10X) 
explosive amounts; (3) the only protection needed on each 
person was a gas mask with special filters; (3) a whole 
variety of structures can be fumigated, including dwellings 
containing clothing and bedding; and (4) Zyklon can be 
effectively used at temperatures below five degrees Celsius.  
Taking all of this into account, it would seem that murdering 
large numbers of people with Zyklon-B in specially constructed 
rooms would be relatively simple, given that the gas is highly 
toxic and fairly easy to use for fumigation. 

    The fact that the irritant indicator was removed from 
shipments to Nazi death camps is another curious feature, as 
one would wonder why an obvious safety feature would be 
removed from a product if its intended use was purely benign.  
Eyewitness accounts from individuals such as Fillip Mu"ller 
and documents describing the use of Zyklon-B in the gas 
chambers themselves are all the more damning.
B) A Hypothetical Gassing

    In order to answer the question "How easy would it have 
been to gas people with Zyklon-B?", I will carry out some 
calculations to show just how feasible such a process would 
be.  Specifically, I will use an "average" size gas chamber to 
see how many people could be fit into one, and how many could 
have been killed in 18 months at a camp like Auschwitz, which 
had four large chambers (Krema I and Bunkers I and II will not 
be considered for reasons of simplicity).  I will also discuss 
how much Zyklon B would be needed to reach lethal 
concentration in the room, and how fast 1 kilo of Zyklon would 
have to evaporate to reach the lethal concentration of 300 ppm 
in ten minutes.  

    Imagine a room with 210 square meters of floor space. I 
chose this value as it was mentioned as a typical size of a 
gas chamber in Auschwitz-Birkenau in the Leuchter report FAQ 
routinely posted by Ken Mcvay  
{16}.  I'll simply assume that the walls are 2.5 meters high, 
so the building will have a total volume of 525 cubic meters, 
or 5.25 X 10^5 liters.  

    The structure would be fitted with vents on the ceiling 
for pouring in the Zyklon, and exhaust fans would be be used 
to clear the room once gassing was completed.  This structure 
would be largely below ground, to help maintain a constant 
temperature using the earth as insulation.  (Not all of the 
gas chambers at Auschwitz were below ground, in fact Kremas IV 
and V were above ground structures.)  Keeping the chambers 
below ground would also allow easy access to the roof.  The 
perpetrators could pour gas in through the roof while wearing 
gas masks. Camp inmates could be used to remove the bodies and 
transport them to the crematoria once the gassing was complete 
and the room had been cleared of gas.  In reality, a quite 
simple operation.

    Also, imagine that there are four such buildings in the 
camp (representing Kremas II, III, IV, and V at Auschwitz), 
and that each has a crematoria to go with it.  For the sake of 
simplicity, each gas chamber will carry out only one gassing 
per day, and the gas chambers will be forcibly ventilated for 
at least one hour.  
    For the specifics of the gassing, let's look at just one 
chamber.  A building with 210 m^2 of floor space can easily 
accommodate four people per square meter (my calculations 
based upon how many people I could fit in one square meter, it 
wasn't even a tight fit)  As I said earlier, the empty volume 
of the room is 525 m^3.  By my calculations, a human person 
will take up 0.081 cubic meters {17}.  At four people per 
square meter, that's 840 people in one room, which take up 
68.04 m^3 of space.  That leaves a free volume of 456.96 m^3 
(457 m^3 from now on.)

    To show (1) how much Zyklon it would take to reach the 
lethal 300 ppm level, and (2) how fast 1 kilo of Zyklon would 
have to evaporate to reach 300 ppm in ten minutes, we need to 
know how much volume one kg of air takes up.  Ideal gas 
assumptions say that one mole (6.021 X 10^23 molecules) of gas 
occupy 22.4 liters at 25 deg Celsius {18}.  One mole of gas is 
21% oxygen an 79% nitrogen (ignore the 1% of other gases and 
assume they're not there.)  Multiply this times the molecular 
weight of the gases (grams per mole of gas, 28g for N2, 32g 
for O2) and the weight of one mole of gas is (0.21)*32 + 
(.79)*28 = 28.84 grams, or 0.02884 kg per 22.4 liters (the 
vol. of one mole of gas).  One kilogram of gas will therefore 
occupy 776 liters of volume.

    How much Zyklon-B will be needed to reach a concentration 
of 300 ppm?  300 ppm HCN corresponds to 300 milligrams of HCN 
per kilogram of air.  For 457 cubic meters of air, you need to 
do some manipulations:    

    457 m^3 = 4.57 X 10^5 liters * (1 kg air/ 776 liters) 
                                =  589 kilos of air.

   (0.300 grams HCN/ kg air)*(589 kg air) = 176.7 grams HCN.

   ...less HCN than is contained in one can of Zyklon-B.  In 
reality, if only 176 grams of HCN are poured into such a 
room,they may have to wait some time before everyone is dead.  
What if you pour in a whole kilogram of HCN?

   The question now becomes, If 1 kg of HCN (5 cans) are 
poured into our gas chamber, how fast will the HCN have to 
evaporate to reach a lethal concentration in ten minutes?  For 
this example, I will assume a constant rate of evaporation on 
a per gram basis.  The rate of evaporation will be:

        176.7 grams HCN/10 minutes = 17.67 grams/minute
        (17.67 grams HCN/minute)/(1000 g HCN) X 100 = 1.76% 

    Only 1.76% of the HCN will have to evaporate per minute.  
Actually, the numbers would be slightly different as there 
will be less HCN each minute, so 1.76% won't be as much HCN 
after eight minutes as it was in the first.  Taking this loss 
of material into account, even a constant 1.76% evaporation 
rate takes only 12 minutes.  For a substance that is normally 
a gas at room temperature, an evaporation rate this slow seems 
quite probable.  As HCN boils at 26 degrees Celsius, it is 
quite likely that the gas will evaporate much faster than 
1.76% per minute.

    I have searched for experimental kinetic data on HCN 
evaporation to no avail.  If anyone knows where I get some 
data (short of doing the expts myself), let me know.  This 
information would be particularly useful in answering the 
question: "How fast HCN would actually evaporate?"

    With only one gassing a day, plenty of time will be left 
for ventilating the gas chamber and moving the bodies to the 
crematoria for combustion. The next question is, given one 
gassing a day and four gas chambers at the camp, how many 
people can be killed in a time period of one and one half 
years (18 months)?  I chose this time period since the four 
large extermination facilities at Auschwitz-Birkenau were in 
operation from 1943 until their destruction by the fleeing 
Nazis in November 1944 {19}.  For the sake of argument, I'll 
say that's about 1 1/2 years (May 1943 to Nov. 1944).

    If the gas chambers were in operation for 548 days (1 1/2 
yrs), the total dead would be:

        (840)*(4)*(548) = 1,841,280 dead from gassing alone.
    Most estimates say that 1 to 2 million died at Auschwitz 
altogether, including deaths from starvation, torture, summary 
execution, and medical experiments.  Clearly then, based upon 
my largely hypothetical example, it was both possible and 
feasible to murder that many, even in a fairly short time 
scale of 584 days with just four working gas chambers.  In the 
case of Auschwitz, an even shorter time of operation would be 
necessary as not all of the 1.6 million were murdered in the 
four main gas chambers.  Executions by firing squad and 
gassings in the makeshift Bunkers I and II were also carried 
out.  Also, many more died from starvation, torture, and 

    The only limiting factor would be the crematoria for 
disposing of the bodies, as one could conceivably produce 
bodies much faster via gassing than could be cremated.  Given 
the number actually killed at Auschwitz this may not have been 
a problem -- see the letter to SS Gen. Kammler below (also ref 

C) Relate to Existing Documents on the Holocaust 

    Many documents discussing the operation of the gas 
chambers at Auschwitz exist.  The testimony of Hanz Stark is 
an excellent example {20}.  Hanz Stark was connected with 
Auschwitz's "Political Department", and was responsible for 
registering new arrivals to the camp.  He was also responsible 
for observing executions carried out in a room next to Krema 
I, initially carried out with a small caliber rifle.  The 
terminology used for people dispatched in this manner was 
Sonderbehandlung -- special treatment in English.  Prisoners 
who had received "special treatment" were said "to have been 
found special lodgings."  Stark was quite explicit that this 
meant execution.  

    Later on, "experimental" gassings took place in the 
execution room adjoining Crematoria I.  Stark was also a 
witness to gassings that took place there, and his description 
is quoted here (in English, typos are mine):

    "As I have already mentioned, the first gassing was 
carried out in the small crematoria in autumn 1941.  Grabner 
ordered me to go to the crematorium in order to check numbers, 
just as I had had[sic] to do with the shootings.  About 200-
250 Jewish men, women, and children of all ages were standing 
at the crematorium.  There may also have been babies there 

[....]  Nothing was said to the Jews.  They were merely ordered 
to enter the gas chamber, the door of which was open.  While the 
Jews were going into the room, medical orderlies prepared for 
the gassing.  Earth had been piled up against one of the external 
walls of the gassing room so that the medical orderlies could get 
onto the roof of the room.  After all the Jews were in the chamber, 
the door was bolted and the medical orderlies poured Zyklon-B 
through the openings..."

And as he later describes in a gassing he participated in 

    " As the Zyklon-B - as already mentioned - was in granular 
form, it trickled down over the people as it was being poured 
in.  They then started to cry out terribly for they now knew 
what was happening to them [...] After a few minutes there was 
silence.  After some time had passed, it may have been ten to 
fifteen minutes, the gas chamber was opened.  The dead lay 
higgeldy piggeldy all over the place.  It was a dreadful 

    Note that these gassings took place at Krema I, a much 
smaller structure than the homicidal gas chambers constructed 
at the Birkenau complex (Krema II, III, IV, V).  This explains 
why the chamber had a much smaller capacity, and earth had to 
be piled up along side the room to allow access to the roof.  
Other than that, the process is similar to the one I described 
in the "hypothetical gassing" section.  

   The testimony of Auschwitz camp commandant Rudolf Ho"ss 
is also very useful {21}.  With regards to the gassing 
process, he describes both gassings in the large chambers in 
the Birkenau complex and ones carried out in the makeshift 
Bunkers I and II.  Bunkers I and II were used while the major 
extermination facilities were under construction, and had a 
capacity of about 200-300 people at once.  The process in the 
bunkers was similar to that in Krema I (see above).  The 
extermination chambers was somewhat different, as Ho"ss 
mentions that they where equipped with an electric ventilation 
system to quickly ventilate the rooms, and an electric lift to 
quickly transport bodies to the Krema ovens for incineration.  
Here the gas chambers were located underground, which allowed 
easy access for pouring Zyklon-B into the chambers.  

    Aerial photographs of the camps taken by allied 
reconnaissance planes during the war corroborate Ho"ss 
testimony, particularly with regards to the architecture of 
the underground gas chamber in Krema II {22}.

    A particularly gruesome testimony is provided by former
camp inmate Marie-Claude Vaillant-Couturier {23}:

Extract from evidence given at the Nuremburg Trials on the 
Auschwitz Extermination Camp:

M. DUBOST:  Did you actually see the "selection" when 
transports arrived?

VAILLANT-COURIER:  Yes, because when we were working in the 
Sewing Block in 1944, the block in which we lived was situated 
just opposite the place where the trains arrived.  The whole 
process had been improved:  Instead of carrying out the 
"selection" where the trains arrived, a siding took the 
carriages practically to the gas chamber, and the train 
stopped about 100m from the gas chamber.  That was right in 
front of our block ..

    They were taken to a red brick building with a sign that 
said Baths.  There they were told to get undressed and given a 
towel before they were taken to the so called shower room.  
Later, at the time of the large transports from Hungary, there 
was no time left for any degree of concealment.  They were 
undressed brutally.  I know all these particulars because I 
was acquainted with a little Jewess from France .... when I 
got to know her she worked on undressing the small children 
before they were taken into the gas chamber.

    After all the people were undressed they were taken into a 
room that looked like a shower room, and the capsules were 
thrown down into the room through a hole in the ceiling.  an 
SS man observed the effect through a spy-hole. After about 5-7 
minutes, when the gas had done its job, he gave a signal for 
opening the doors.  Men with gas masks, these were prisoners 
too, came in and took the bodies out.  They told us that the 
prisoners must have suffered before they died, because they 
clung together in bunches like grapes so that it was difficult 
to separate them.... 

    There are also documents discussing exactly how many 
people could be killed, and how many bodies could be cremated 
in a given day.  For example, Ho"ss mentions that a maximum 
number of 10,000 people could be gassed in a given day (note 
that this is the number _gassed_, not cremated.) A letter sent 
to Berlin, addressed to SS General Kammler mentions that the 
total number of bodies that could be processed in one day as 
4,756 {24}. Note that this figure includes cremation of the 
bodies as well as gassing. Based on this document, a total of 
2.6 million people could be murdered and their corpses 
disposed of in just one and one half years (548 days).  This 
is hardly a poor generalization, as the major extermination 
facilities at Auschwitz went on line in late 1942 (Krema II 
and III) and mid 1943 (Krema IV and V) {25}.     

    Based on the figures in the letter, my numbers generated 
from the "hypothetical gassing" may err on the side of 
caution.   Note that I am not claiming that 2.5 million plus 
were killed at Auschwitz, as I do not know the exact figure.  
It should be self evident that the murder of about 1 to 2 
million people in these camps (or even more) was not 
only feasible, it was well documented.  There are many more 
volumes of documents on the Holocaust, and one need merely 
search their local library to find many volumes of them.  

Conclusion and Summary    

    In the preceding sections, I have (hopefully) shown how 
cyanide acts as a poison, the relative ease with which it was 
used for fumigation, and how it was used to murder hundreds of 
thousands of innocents in gas chambers.  Let me reiterate my 
points very quickly:

1) Cyanide is very poisonous and kills by inhibiting oxidative 

2) Cyanide was commonly used for fumigation with relative 

3) With a modification of procedures used for de-infesting a 
building, Zyklon-B could easily be used to murder over one 
million people in 1 and 1/2 years.

4) Documents exist that discuss how gassing was done at 
Auschwitz, and how many people could be killed and cremated 
in a given time period.  

5) These documents support my hypothetical example and 
give detailed accounts of the gassing process.

If anyone has any questions or comments you can reach me 
at the following addresses:
        (after 10/14/94)

and also:

        Brian Harmon
        439 Kirkham St.
        San Francisco, CA 94122

        I am currently a graduate student in Biochemistry and 
Molecular Biology at the University of California, San 


i. Qualifications of The Author:

        I have Bachelor of Arts Degrees in Zoology 
and Chemistry from Miami University, Oxford, Ohio 45056.  
I also have over two years of research experience as of 

ii. Copyright Notice

    (c) Brian Harmon, April 1994. This may be distributed 
freely, provided it is not modified in any way, and all 
credits are given  to the author.  Any altering of this 
document without express consent of the author is hereby 
forbidden.  Quoted material in this text is copyrighted by the 
publishers of the original source(s).

iii.  Acknowledgements:

    I would especially like to thank Danny Keren for his 
help on this project.  I also would like to thank Ken McVay 
for his assistance, and for Charles Egger for functioning as a 
second reader and editor. 


1) All biochemical Data and information is taken from:

Voet, Donald and Voet, Judith G.  _Biochemistry_. (New York:  
John    Wiley and Sons)  (c) 1990, 1223 pp.
Another source worth looking at is:

"Cyanide Toxicity".  Agency for Toxic Substances and Disease
        Registry, U.S. Dept of Health and Human Services.  in
        _American Family Physician_, Vol. 48, no 1, July 1993.
        pp 107-113.  

2) Voet, p 530.

3) ibid, p 546 and Dr. Jan Jaworski, personal communication.

4) ibid, p 549.

5) Elkins, Hervey B.  _The Chemistry of Industrial 
Toxicology_.  (New York:  John Wiley and Sons Ltd.)  2nd ed., 
(c) 1959, p 94

6) Voet, pp 538-544.

7) ibid, p 545 (figure).

8) ibid, p 535.

9) ibid, p 222.

10) Elkins, p 94

11) ibid, p 94

12) Nuremburg Document NI-9912, the Degesch Manual on how to 
use Zyklon properly.  I obtained both German and English 
versions from:
        Mendelsohn, John and Detwiler, Donald S.  _The 
Holocaust:  Selected Documents in Eighteen Volumes._   "Volume 
12: The 'Final Solution' in the Extermination Camps and the 
Aftermath"  (New York:  Garland Publishing) c. 1982,  p 137.

13) Nuremburg Doc NI-032, from Mendelsohn and Detwiler, p 128.

14) Nuremburg Doc NI-9913-A (excerpts)  from Mendelsohn and 
Detwiler, p 149.

15) The Degesch manual is form Mendelsohn and Detwiler, pp 

16)Mcvay, Kenneth N. (1993) "HOLOCAUST FAQ:  The Leuchter Report"  Available via anonymous ftp 
from in pub/usenet/news.answers/holocaust
/leuchter/part01 (and ~part 02).  approx. 23 pages,   p 4. 

17) I assumed that a human was merely a rectangular box, 
neglecting the head.  The height of the box was measured from 
the shoulders to the floor, the breadth was measured across 
the chest at sternum level, and the depth was also measured at 
the same height.  Based upon five people, the average 
measurements were (rounded off the the nearest cm):  150 X 36 
X 15 cm.

18) In an ideal gas, the atoms/molecules do not interact with 
each other.  While this is clearly not the case, for order-of-
magnitude calculations this assumption is fairly accurate.

19) Brugioni, Dino and Poirier, Robert.  _The Holocaust 
Revisited:  A Retrospective Analysis of the Auschwitz-Birkenau 
Extermination Complex_.  (Washington D.C.:  Central 
Intelligence Agency).  (c) Feb. 1979,  p 13

20) _"The Good Old Days": The Holocaust as Seen by Its 
Perpetrators and Bystanders_. ed by Ernst Klee, Willi Dressen,
and Volker Reiss.  English translation of "Die Scho"ne Zeit".  
(New York: The Free Press, div. of MacMillan, Inc.)  (c) 1991. 
pp 252-255.

21) _The Good Old Days_, pp 271-273.

22) Brugioni and Poirier, p11.

23) _Documents on the Holocaust: Selected Sources on the 
Destruction of the Jews of Germany and Austria, Poland, and 
the Soviet Union_.  ed. by Yitzhak Arad, Yisrael Gutman, and 
Abraham Margaliot.  (Jerusalem: Yad Veshem) (c) 1981, pp 358-

24) McVay, p 10.  A GIF of the letter can be obtained via 
anonymous FTP from  -- send the 
command GET GIFS AUDOC001.GIF  .

25) _The Good Old Days_, p 271    

Home ·  Site Map ·  What's New? ·  Search Nizkor

© The Nizkor Project, 1991-2012

This site is intended for educational purposes to teach about the Holocaust and to combat hatred. Any statements or excerpts found on this site are for educational purposes only.

As part of these educational purposes, Nizkor may include on this website materials, such as excerpts from the writings of racists and antisemites. Far from approving these writings, Nizkor condemns them and provides them so that its readers can learn the nature and extent of hate and antisemitic discourse. Nizkor urges the readers of these pages to condemn racist and hate speech in all of its forms and manifestations.