Gas Chamber construction at Auschwietz/Birkenau

Factual Questions
1

I was watching a documentary on PBS about the evolution of Auschwietz. From it’s original plan as a work camp to get the needed minerals to germany for synthetic rubber, to the plans for it to be a new city just for the aryans to it’s final transition to what it became.

One of the things they discussed is how the methods of execution evolved as well from the firing squads up to converting an old farmhouse into the first gas chamber. In the film and in the construction plans, they showed how the doors and windows were bricked up, new doors were added on the sides (the divided the house into 2 rooms instead of one big one), and then the hatches for the adding of the Zyklon B powder. The thing that puzzled me is on the doors, there was a sort of porthole. I can only assume this was used to look in before opening it to see if the people insde were dead or not. However, this porthole looked to be just a hole. No glass, no sealant. Also, the hatches used looked to be just a sort of metal flap they lifted with no sort of sealant around the edges.

My question is this, how is it that the guards didn’t end up being exposed to large amounts of gas themselves? I would think the presence of a few of these leakable sites (for lack of a better term) would have caused the gas to escape from these chambers into the air, and also make the actual process of death take longer (not that they were worried aboutthis I’m sure).

Were there cases of guards accidentally gassing themselves?

2

The porthole in the door would have had a glass window, but the hatches were indeed just flaps. It was thus standard practice for the guards dropping the pellets through the hatches to wear gas masks. It was also known for those in the vicinity to wear them as well; for example, Hoess mentions in his memoirs donning one to supervise one of the early gassing.
Offhand, I believe the Sonderkommando, the prisoners forced to do the hard labour of running the chambers, also wore them when clearing the bodies afterwards, even though there was usually a mechanical ventilation system to extract the gas.

Haven’t heard of any, though it’s always possible.

3

Interesting, the way they were showing the construction of the early gas chambers it didn’t look like there was any ventilation system at all. I wonder if that was in the larger scale buildings they made.

4

I seem to remember the tour guide mentioning that there was a mechanical ventilation system in the permanent gas chamber that was built at Birkenau. Some of us tourists had asked exactly this question.

5

The toxicity of cyanide, like any other poisonous gas, depends on concentration and the time of exposure. 150 ppm is potentially fatal within an hour; 300 ppm is fatal within a few minutes. (At room temperature, cyanide has a vapor pressure of 987,000 ppm, which means that it is capable of reaching this concentration if there is enough solid HCN present; in other words, the solid compound turns rapidly into vapor.) It is not clear what concentration was used, though witnesses report that the people inside died within 5 to 20 minutes – which doesn’t require a very high concentration.

According to this page (from which I also obtained the concentration data above), the two underground gas chambers had ventilation systems, and the two that were built above ground used natural ventilation. Even with natural ventilation, the concentration of HCN in the atmosphere immediately outside the gas chamber would be much, much smaller than within, because the gas diffuses quickly in the atmosphere. Once ventilation began (whether mechanical or natural), the concentration inside the chamber would drop very quickly. The actual time that it would take would depend on the amount of HCN introduced, the rate of ventilation, and the temperature. It is certainly plausible that the concentration of HCN in the gas chambers was below fatal levels within the times described by witnesses, particularly if the Sonderkommando used gas masks.

See here for more information on the columns, including some surviving photographs. Since the cyanide was introduced from outside, any HCN that escaped from the top of the column would quickly dissipate into the atmosphere. Most accounts of the homicidal process mention that those who handled the Zyklon crystals wore gas masks. A gas mask to counter HCN is relatively simple – all that is necessary is a compound, such as a nitrite, that oxidizes CN[sup]-[/sup] to cyanate, OCN[sup]-[/sup]. Additionally, cyanide poisoning can be reversed if treatment is given within a few minutes.

Finally, the Zyklon-B compound itself has some features that make it less likely that there were many accidental deaths resulting from its handling. (See here again.) There were two irritants in the compound – one that dissipated quickly, before the HCN concentration was life-threatening, and one that lingered. Those handing the gas, as well as the Sonderkommando who entered the gas chambers after the homicidal process, would have known from the presence of the warning compounds that there was gas present, and could have either worn a gas mask or left the area.

It seems unfortunate, in a way, that the gas used to murder perhaps a million people was not extremely dangerous to those who handled it. But these issues – the risk to those outside the chambers, and the time it took for the chambers to be cleared of gas – are important in countering Holocaust denial. Some deniers have claimed that the gas was so dangerous that it would have killed those who handled it, or that it lingered for so long (or that the bodies were so toxic afterwards) that it would have been impossible to kill as many people as historians claim were killed. The URL I linked to deals with these claims, and there are quite a few others.

6

To add what was missing from my previous post, a specific eyewitness account of the use of gas masks. From Dr. Miklos Nyiszli’s Auschwitz: A Doctor’s Eye-witness Account (1962; Granada, 1973, p48):

This all refers to the procedure at one of the later, specially build, chambers where most of the killing took place, rather than in the converted farmhouse.
Holocaust deniers have claimed that Nyiszli’s book was a fake, but only on extremely tenuous grounds.