This is meant to be a factual discussion, not a debate over death penalty issues.
What would be the downside of using CO (carbon monoxide) gas for executions?
Assume a “gas chamber” setup, with, say, three valves, any two of which being opened will begin to replace the chamber atmosphere with CO. Assume five minutes for complete replacement of the atmophere, after which it would be 95%+ CO.
My understanding of CO poisoning is that the body cannot distinguish it from O2 and keeps on happily loading it onto red blood cells, causing the body systems to slowly suffocate. There is thus no “poison reaction” or much of any moment when the brain or body realizes it’s dying. With sufficient concentration, unconsciousness occurs fairly quickly, followed by brain death within ten minutes or so, followed by cardio failure a few minutes later. The subject literally goes to sleep, then brain-dies, then dies quietly.
CO is not particularly toxic should trace amounts escape from the chamber or remain when personnel enter to verify death.
CO is extremely cheap and can be purchased on the open market or chemically created by many simple reactions, meaning no supply issues.
Not quite right: hemoglobin has a much stronger affinity for CO than for O2. This is why CO is problematic in very small concentrations, even in an oxygen-rich atmosphere.
That lack of as poison response is also a danger factor. Staff and such wouldn’t know if they’d been exposed to it without some sort of test. Also, it’s bond with hemoglobin* is permanent**, so it can build up very easily from repeated exposure. I’m sure the other methods have their downsides as well, those are just the problems with CO poisoning.
or whatever the specific part that binds with O2 is .
** until that particular cell or whatever it’s replaced, which happens on a regular schedule (think it’s ~3 months or so)
For a long time, veterinarians used it. In old times, they just backed a car up to the doghouse.
I have never heard of a downside, and it is my understanding that people who accidentally died of CO poisoning never showed any signs of a struggle. I believe, though, that you’d be aware that you were dy8ing because while still conscious, you’d lack the muscle strength to get up and walk away, or even open a window.
As indicated above, operators would need to completely replace the CO with O2 before entering the chamber.
Inert gas asphyxiation is supposedly painless; I believe any inert gas could be used (such as helium, which is sometimes used in suicides) but nitrogen gas would be cheaper (and less likely to cause inappropriately comic effects).
Okay, CO is more dangerous in low quantities than I allowed. But it’s not strictly toxic like cyanogen gas, and there are inexpensive and reliable detectors for it.
I had not realized that CO poisoning is essentially permanent, on an RBC level.
High-altitude anoxia can lead to a panic stage, can it not, as the body realizes it’s going hypoxic and struggles? Same for inert gas asphixiation? My understanding is that the body never quite realizes what’s going on with CO poisoning, since the oxygenation process continues “normally.”
The poisoning issues should only come into play with slow poisoning, right? Exposure to trace CO until poisoned RBCs are built up in the circulation? If it’s at a higher concentration that produces more rapid unconsciousness, wouldn’t these effects be minimized?
Sorry, I meant “exposed to” as in “inhaled”. Exposure to it is almost certain unless strict control measures are taken (same as for “conventional” poison gas), which would negate one of the chief benefits mentioned by the OP.
Also, Machine Elf explained the “permanent” aspect much clearer than I did.
For unwitting or unaware people, maybe. But a condemned person would know perfectly well what was about to happen, and be very alert to the slightest symptoms or change in sensation.
I’ve found this: INERT GASES (Death by Asphyxia, Most Humane way To Die) (Copyright: 2005-7 by Death Penalty Improvement Group)
… carbon dioxide would be an unpleasant choice, since its presence stimulates both breathing reflexes and the sensation of smothering.The hydrocarbons methane, butane, liquified petroleum gas (LPG), and propane, while readily available as fuel gases, are normally mixed with bad-smelling “warning” gases (mercaptans), related to skunk scents.
Acetylene is used for gas welding and is easy to acquire, but contains somewhat-toxic acetone. It’s not wise to make own acetylene from calcium carbide because it contains an ammonia-like contaminant, phosphine (PH3). Freons are bad for the ozone layer and so is neon & it’s expensive. Hydrogen is flammable (remember the Hindenberg) and raises the pitch of voice just like H. The remaining gases, argon, helium, and nitrogen, are best gases in this category. They are all tasteless, odorless, non-irritating, and under these conditions, chemically and physiologically inert.
I’m not sure being forewarned makes much of a difference - in all of the laboratory experiments I’ve seen or heard about, even though the subject knew they were going to be deprived of oxygen and knew the sort of thing to expect, they still seemed to be caught unawares and some later reported that it crept up on them.
