Why have people stopped committing suicide with gas?

Sticking your head into an oven, or at least sitting quietly in your easy chair with the (unlit) gas jets on and the windows closed, was once a standard suicide method on stage, screen, and in real life. Black and white movies and mid-century pulp fiction are filled with nick-of-time rescuers breaking down doors, shouting "Gas!" and frantically opening the windows; real life victims include poet Sylvia Plath. Yet you never hear about this anymore. What happened?

Suicide by gas didn't go out of style - it just became a whole lot less convenient. The gas piped into your house these days is not your grandfather's gas. Modern gas companies deliver "natural gas," a naturally occurring fossil fuel that is a benign mixture of methane and ethane. It only smells terrible; it's really not that lethal. Safety types call it a "simple asphyxiant." Turn on your gas jets and yes, you will die, but only after the gas displaces most of the oxygen or, more likely, reaches the pilot light and explodes. Who has that kind of patience? And who can stand that smell that long?

The gas it replaced, "coal gas" or "illuminating gas" was another matter entirely. It was manufactured locally at "gasworks" from coal heated in airtight chambers. The gas produced, a mixture of methane, hydrogen and carbon monoxide, not only burned beautifully, but was perfect for the suicidally-inclined. The active ingredient was, of course, the carbon monoxide. With blood having more than 200 times the affinity for carbon monoxide than oxygen, it doesn't take much to saturate the blood and starve your brain and nervous system of oxygen. A few breaths of 1% carbon monoxide is enough to knock you out; a few minutes breathing it will kill you. With coal gas running 10% carbon monoxide, it's not hard to see why one psychologist called old fashioned coal gas ovens "the execution chamber in everyone's kitchen." Like all good technologies, it was fast, convenient, and effective.

Advances in metallurgy and welding technology in the 1930s and 1940s brought coal gas industry to an end. Natural gas, formerly a nuisance byproduct of oil drilling that was frequently simply burnt at the wellhead, could now be transported long distances cheaply and easily. After World War II, American cities and towns rapidly switched over to the new safer natural gas. The local gas plant joined horse trams and coal furnaces on the dust heap of discarded technology. The transition in Britain was a little slower, with a few gasworks limping into the ‘70s. The only remaining legacy of this formerly robust industry is numerous abandoned brownfield sites contaminated by the process's coal-tar and ash byproducts.

The switch from coal gas to natural gas also had one unexpected effect. During the ‘50s and ‘60s, about half of the suicides in Britain were by coal gas. By the ‘70s, when the transition to natural gas was complete, the number of gas suicides had dropped to zero and the overall suicide rate was down a third. Even the suicidal appreciate convenience. If it's too much trouble, as Dorothy Parker said, "You might as well live."