How do we know a diesel engine can produce enough carbon monoxide in its exhaust to kill people?
Holocaust deniers claim:
The idea of using diesel engine exhaust to murder some 1,400,000 Jews in the gas chambers of Treblinka, Belzec, and Sobibor is idiotic because diesel exhaust is not lethal.
For example, Friedrich Berg, an American Holocaust denier, is the author of a series of articles in which he claims that using diesel engine exhaust to kill human beings is “idiotic” and “simply incredible.” According to Berg, diesel exhaust is not lethal because it “always” contains “less than 1% carbon monoxide.” Berg’s articles appear technically impressive because they contain charts and graphs, leaving the average reader with the impression that his assertions are backed up by science.
The facts are:
Two separate scientific studies show that it is possible to adjust a diesel engine to produce a lethal amount of carbon monoxide.
The facts about Berg’s “science”:
Two peer-reviewed scientific studies performed by qualified engineers show that diesel engine exhaust can contain lethal amounts of carbon monoxide. It is possible that diesel engines could be used to murder human beings.
The first study was conducted in 1941 by Holtz and Elliott. This study analyzed the chemical composition of exhaust from diesel engines under different running conditions.
The second study was done in 1957 by R.E. Pattle et al. In this study, small animals were placed in a container filled with diesel engine exhaust and studied for their reaction.
What the 1957 study by R.E. Pattle et al found:
In the Pattle study, the exhaust from a single-cylinder diesel engine was directed into a chamber with a volume of 10 cubic meters (353 cubic feet) of air in which mice, guinea pigs, and rabbits were placed. The engine was then run for five hours in four different modes until the animals were dead, disabled, or clearly going to survive.
In Mode A, the engine was run according to the manufacturer’s specifications. The animals survived the entire five hours and recovered with no ill effects.
In Modes B and C, the engine was slightly modified. Some of the animals died in the fourth hour of the experiment and others died several days later from severe lung damage.
However, in Mode D, in which a metal blank was used to reduce the size of the air intake, all of the animals died in three hours and 20 minutes. Analysis of the atmosphere in Mode D showed that it contained 22 percent carbon monoxide (or 220,000 parts per 1,000,000). For humans, a carbon monoxide concentration of 4/10 of one percent (.4%) or 4,000 parts per 1,000,000 parts of the atmosphere is lethal.
What the Holocaust deniers say about the Pattle et al study:
Holocaust deniers like Berg ignore the fact that some animals died in Modes B and C. Instead, Holocaust deniers explain away the importance of the fact that all of the animals in Mode D died by focusing on the fact that the deaths took longer than 30 minutes—which is what eyewitnesses say was about the time it took to kill a small room or truck full of human beings.
Comparing the conditions for the animals in the Pattle study with the conditions in the gas chambers (for humans) is comparing apples and oranges:
First: The method of introduction of the animals into the cage and the people into the gas chambers was fundamentally different.
The small animals in the Pattle study were healthy and not stressed when they placed in the chamber. The Nazis and their collaborators, however, often drove their terrified human victims at a running pace into the gas chambers. They used whips, dogs, and guns to assure this pace. People who are panicked or panting heavily will breathe in the carbon monoxide, smoke, soot, and the other toxins more quickly. They also exhale carbon dioxide that builds up in the atmosphere which further disables their ability to breathe freely. Further, many of those murdered were elderly, very young, or physically debilitated due to starvation and sickness—all of which would have impacted their intake of carbon monoxide.
Second: The size of the spaces, relative to their occupants, was unequal. This makes any comparison between the effects on the animals in a box and people in a gas chamber irrelevant.
In the Pattle et al. study the small animals were placed in an enclosure that had a volume of 10 cubic meters (353 cubic feet) of air. In the gas chambers, hundreds of human beings were pushed tightly into a space that contained somewhere between 1,412 and 1,765 cubic feet. Their bodies alone displaced most of the air in the space and what little was left to breathe was rapidly replaced by toxic gases.
There is evidence corroborating that the Nazis took space into account when adjusting the size of the gas vans. Willy Just was a foreman at the shop where adjustments were made to normal trucks, turning them into gas vans. Just wrote a letter to Walther Rauff, the head of the gas van program, where Just noted that shortening the length of trucks by three feet would allow them to be filled with toxic exhaust in “considerably less” time 
If, in Mode D, Pattle had put the animals into an area only an inch larger than they were, how much more quickly would they have died? We don’t know, but it is safe to assume it would have taken less than 3 hours and 20 minutes.
How do we know adjusting the engines was a simple procedure?:
Adjusting the fuel pump or blocking the air intake does not require mechanical or engineering skills that were outside the capabilities of the SS technicians who ran the engines, as the perpetrators themselves testified.
For instance, Erich Bauer, the “Gasmeister” (“Gas Master”) at Sobibor, specifically testified that he had “worked with motors.” Similarly, Erich Fuchs, who also served at Sobibor, described an instance when he had to repair the engine: “We installed the engine on a concrete base and connected the exhaust to the pipeline. Then I tried the engine. It hardly worked. I repaired the ignition and the valves, and finally got the engine to start.” These repairs are more complex and skilled than making a simple adjustment of the air intake or fuel mixture on the engines. Some of the Ukrainians auxiliaries were also mechanics.
The work of Holocaust deniers like Berg is junk science. Murdering people using diesel engine exhaust is not “idiotic” or “simply incredible” as Berg claims.
Peer-reviewed studies done by qualified engineers show that animals can die from exposure to diesel engine exhaust, as long as slight adjustments are made to the engines. In these studies, some animals survived and others died after a period of several hours in relatively spacious conditions. However, conditions in the gas chambers were different. Panicked, unhealthy human beings were crammed into a much tighter space, which was then filled with toxic exhaust from adjusted diesel engine. In such conditions, evidence indicates that humans could die within 30 minutes, either from carbon monoxide poisoning, lack of oxygen, or both. Available testimony indicates that the SS men and the Ukrainian auxiliaries had the ability to perform repairs and make the required adjustments.
 Friedrich Berg, “The Diesel Gas Chambers: Myth within a Myth” at http://www.ihr.org/jhr/v05/v05p-15_Berg.html.
 Friedrich Berg, “Pat Buchanan and the Diesel Exhaust Controversy” at http://www.nazigassings.com/PatBuchanan.htm and Friedrich Berg, “The Diesel Gas Chambers: Myth within a Myth”.
 Berg’s original paper, “The Diesel Gas Chambers: Myth Within a Myth,” was published in the Journal for Historical Review in 1983. He has since expanded on his original theme in several other articles which can be found at his website at www.nazigassings.com. (Warning: This site is graphic and offensive.)
 You may read the study “The Significance of Diesel-Exhaust-Gas Analysis” by John C. Holtz and M.A. Elliott, Transactions of the ASME (American Society of Mechanical Engineers), (1941) 63(2) at http://cybra.lodz.pl/Content/6253/v63no2_1941.pdf , go to their page 18.
 R.E. Pattle, H. Stretch, F. Burgess, K. Sinclair and J.A.G. Edginton, “The Toxicity of Fumes From a Diesel Engine Under Four Different Running Conditions,” British Journal of Industrial Medicine, (1957), 14 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1037740/pdf/brjindmed00217-0053.pdf .
 For an extensive discussion of this matter see Jonathan Harrison, Robert Muehlenkamp, Jason Myers, Sergey Romanov and Nicholas Terry, Belzec, Sobibor, Treblinka: Holocaust Denial and Operation Reinhard. A Critique of the Falsehoods of Mattogno, Graf and Kues (“Corpse Color”), pp. 328-333 at http://holocaustcontroversies.blogspot.com/2011/12/belzec-sobibor-treblinka-holocaust.html.
 The letter can be read in English at http://holocaustcontroversies.blogspot.de/2015/10/contemporary-german-documents-on.html#_doc4.
 Jonathan Harrison, Robert Muehlenkamp, Jason Myers, Sergey Romanov and Nicholas Terry, Belzec, Sobibor, Treblinka: Holocaust Denial and Operation Reinhard. A Critique of the Falsehoods of Mattogno, Graf and Kues at http://holocaustcontroversies.blogspot.com/2011/12/belzec-sobibor-treblinka-holocaust.html. See pp. 283, 317 (Bauer) and pp. 288, 191 (Fuchs). For the Ukrainians who serviced the engines, see p. 324.