According to Richard J Kinch :
Chris Lewis writes:

"Near zero" CO emissions from cars can kill you if you're not
ventilating well enough. Starting a car in a closed garage and
sitting in the car to read a book is about the easiest and gentlest
ways to die there is.

Bunk. The pCO2 respiratory stimulation will kick in long before integrated
pCO is enough to affect anything. Car exhaust is nearly pure CO2 and
steam, plus very tiny amounts of things like CO. As a suicide method, it's
absolutely stupid, because the mostly likely outcome is a brain-damaged but
still-alive subject.

[Okay, I won't quote the only suicide that I'm personally aware of.]

Bunk still.

You're missing a critical difference between how CO2 and CO affects
the body.

CO2 _primarily_ works by simple displacement of O2, and at high enough
levels suppression of breathing (at mid levels it encourages breathing,
at very high levels it suppresses it).

If you remove someone from a CO2 situation short of brain damage occuring,
they recover pretty instantly.

In other words, CO2 in == CO2 out (more or less). The body is designed
to expell CO2.

In contrast, CO inhibits O2 transfer no matter how much O2 is in your
lungs. Not only that, it's expelled very slowly. It "bioaccumulates"
at any exposure level above a very low threshold. Once you've been
CO-poisoned, you have to have breathing support (ie: pure O2 or
hyperbaric) long enough for your body to have a chance to get rid of the CO.

Thus, in anything short of a perfectly sealed environment, it's VERY
common for the CO2 levels to never reach hazardous levels and being able
to survive it indefinately, but the CO level in the blood starts to
rise.

Thus, operating a gas generator for a long period of time (hours)
when there's the slightest exhaust leak to living areas is _extremely_
hazardous. Because the CO2 concentration (and smell) may never get
strong enough to do something about. But the CO level in your blood is
going up and up and ... even tho you're getting plenty of O2, your blood
doesn't want it. You die without even noticing, because you're breathing
acceptable levels of CO2.

Take careful note of the MSDS's and descriptions of CO2 and CO poisoning.

Notice how "shortness of breath" is _not_ a symptom of CO poisoning? That's
why it's so dangerous.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.