I know that gas naturally has no discernable odor. I know that it was given this odor specifically to prevent people from accidentally blowing themselves up when unknowingly around it.
What I don’t know is where they got that smell from (it’s like nothing else I’ve ever encountered), if it had a name before they co-opted it for gasoline, and if it has a name now aside from “gas smell.”
I looked in the archives for this question coming up before. I found a thread started by aha asking Gas how long does it last, but it was not about the gas I was thinking about (I know there are several terms for THAT gas smell), and I even found a poster named GasDr, but he seems to be an Anesthesiologist (Hey doc! I hear you’re a gas at parties! HA, uh, erm… Right…), but none about this.
Yer putz,
Satan :wally
I HAVE BEEN SMOKE-FREE FOR:
Two months, two weeks, five days, 19 hours, 53 minutes and 55 seconds.
3233 cigarettes not smoked, saving $404.14.
Life saved: 1 week, 4 days, 5 hours, 25 minutes.
Well, I thought that sulpher dioxide was added to gas, but I wasn;t quite sure. Turns out I was wrong, because I looked, and it’s something called mercaptan that is added to natural gas to make it smell.
I think it’s mainly ethyl and butyl mercaptan, along with smaller amounts of other mercaptans–similar to the cocktail that gives skunks their distinctive fragrance…<gag>
Ethanethiol (also called ethyl mercaptan) is one such chemical. The smell of ethanethiol is detectable at a concentration of about 20 parts per trillion in air. Natural gas provided by the local utility contains an odorant such as ethanethiol at a much higher concentration (in the parts per million range), so that even a million-fold dilution of the treated gas with air yields an odorant concentration near the threshold of detection. Other odorizing chemicals added to natural gas include 2-butanethiol, 2-methyl-2-propanethiol, 2-propanethiol, 2,2’-thiobis-propane, 1,1’-thiobisethane, and thiacyclopentane: all sulfur-containing organic compounds.
One of our neighboring towns had a leak in a storage facility for mercaptan (stored prior to being injected into the gas lines) a few years back. Calls from everywhere reporting gas leaks…no gas, just mercaptan floating around. Scary.
While it’s clear what chemical is added to the odorless gas that burns in people’s houses, doesn’t the OP also mention gasoline? I thought gasoline had its own smell. Are there specific additives for the stuff pumped into vehicles to aid detection by olfaction?
Umm, Satan, you know when an odd noise comes out of your backside? And there is a green mist in the air? And the dog rolls over and dies? That’s your gas smell.
Nope, you can smell gasoline all by itself. Small molecular weight hydrocarbons, such as methane, ethane, propane(as found in natural gas) are odorless, but as you increase in molecular size, so you do in olfactory detectability. Pentanes (5 carbon atoms)(which is barely a liquid at room temperature) has more of a “nasal sensation” than a real odor, but starting at hexanes, hydrocarbons all have a distinct odor. Gasoline is largely octance and benzene, both of which have distinct odors. As you get even larger (as you approach 12 carbon atoms or bigger) hydrocarbons start to positively stink (think rotten peanuts). Once you get to large enough molecules to get sufficiently solid at room temperature (and thus no significant vapor pressure) like the kinds found in parafin wax, hydrocarbons become odorless again… And that’s today’s lesson in descriptive organic chemistry.
I was once in a mall where a disgruntal ex-gas company
employee left a container of the chemical on the fire
escape. The smell was unbeliveable, and the whole mall
had to be evacuated. It was pretty exciting.
