Auschwitz

The use of poison gas (Zyklon B) at AuschwitzHolocaust deniers often 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 Conclusion

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 ATP.

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 {3}.

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 cytochrome.

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 skin.

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 ETS.

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:

His | ---- Fe(+3)-- Porphyrin molecule (side view) | His

Some cytochromes, however, are open on one of their two faces:

--- Fe(+3)--- | His

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}:

02 | ---- Fe(+2)-- | His

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) | ---Fe(+2)-- | His

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 effects.

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 blue flame. INTENSELY POISONOUS EVEN MIXED WITH AIR. 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. MUST BE HANDLED BY SPECIALLY TRAINED EXPERTS.

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 blood.

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 precautions._

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 dangerous." [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 exposure.

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" "....one 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 disease.

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 24).

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 personally:

" 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 sight."

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 Hoess 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 Hoess testimony, particularly with regards to the architecture of the underground gas chamber in Krema II {22

The use of poison gas (Zyklon B) at AuschwitzHolocaust deniers often 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 Conclusion

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 ATP.

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 {3}.

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 cytochrome.

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 skin.

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 ETS.

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:

His | ---- Fe(+3)-- Porphyrin molecule (side view) | His

Some cytochromes, however, are open on one of their two faces:

--- Fe(+3)--- | His

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}:

02 | ---- Fe(+2)-- | His

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) | ---Fe(+2)-- | His

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 effects.

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 blue flame. INTENSELY POISONOUS EVEN MIXED WITH AIR. 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. MUST BE HANDLED BY SPECIALLY TRAINED EXPERTS.

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 blood.

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 precautions._

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 dangerous." [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 exposure.

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" "....one 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 disease.

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 24).

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 personally:

" 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 sight."

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 Hoess 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 Hoess testimony, particularly with regards to the architecture of the underground gas chamber in Krema II {22

Zyklon B was used in the concentration camps initially for delousing to control typhus. The chemical used in the gas chambers was deliberately made without the warning odorant.

In January or February 1940, 250 Gypsy children from Brno in the Buchenwald concentration camp were used as guinea pigs for testing the Zyklon B gas.[5] On September 3, 1941, 600 Soviet prisoners of war and 250 sick Polish prisoners were gassed with Zyklon B at Auschwitz camp I; this was the first experiment with the gas at Auschwitz. The experiments lasted more than 20 hours.

According to Rudolf Höß, commandant of Auschwitz, bunker 1 held 800 people, and bunker 2 held 1,200. Once the chamber was full, the doors were screwed shut and solid pellets of Zyklon-B were dropped into the chambers through vents in the side walls, releasing a toxic gas. Those inside died within 20 minutes; the speed of death depended on how close the inmate was standing to a gas vent, according to Höß, who estimated that about one third of the victims died immediately. Joann Kremer, an SS doctor who oversaw the gassings, testified that: "Shouting and screaming of the victims could be heard through the opening and it was clear that they fought for their lives." When they were removed, if the chamber had been very congested, as they often were, the victims were found half-squatting, their skin colored pink with red and green spots, some foaming at the mouth or bleeding from the ears Was that to long or not?