Fumes?

steamidge · 20 Oct 2015, 7:29 am

On a recent expedition into the maze drain (never really explored the maze before) I noticed that for significant sections of the tunnels you could smell what I thought was gas. How dangerous can this be? I was only down there for about 1 and a half hours, and I didn't really notice any kind of bad effects.
Thanks

spigot · 20 Oct 2015, 7:56 am

There's a little side tunnel in there that always smells like that (I've only done the drain twice). I wouldn't worry too much about it.

Natural gas from the mains isn't really toxic at low concentrations, but it is an asphyxiant. If there's enough in there to displace the oxygen below 19%, you'll be in danger. Before that, you'll start feeling lightheaded and dizzy. If that happens, get to a better ventilated section immediately.

Problem that I've noticed in drains is that sometimes after lengthy stoops/straddles, you can start feeling exhausted and this might get confused with the effects of a low oxygen level...

The other thing is that natural gas is intentionally tainted with strong-smelling sulfur compounds (typically thiols) so you can smell possible leaks (natural gas is odourless). Unless you have a familiarity with the compounds, you might mistake it for hydrogen sulfide (H2S), which is much nastier (smells like rotten eggs). It's neurotoxic and will burn the crap out of your lungs (it gets hydrolysed to sulfuric acid). I've never encountered dangerous levels of H2S in a drain (which are relatively well ventilated) but it's very common in sewers, which actually need to be designed to get rid of it (otherwise it decomposes the actual tunnel).

Echo · 20 Oct 2015, 8:18 am

As Spigot said there is a section in Maze that I always notice smells like gas. It's on the way to the Camberwell Junction Gutter box. Kinda worried me the first time but since then I've gone back 3 or 4 times and noticed it's always the same.

Nick · 20 Oct 2015, 10:17 am

Echo wrote:As Spigot said there is a section in Maze that I always notice smells like gas. It's on the way to the Camberwell Junction Gutter box. Kinda worried me the first time but since then I've gone back 3 or 4 times and noticed it's always the same.

With no lasting notable brain damage...

Maze is fairly safe, but it's a freaking stormwater drain, so you know...

If you're worried, you can get a gas detector, but they are not cheap. Plus you have to get them calibrated etc.

Will-043 · 20 Oct 2015, 1:31 pm

cheaper to get a canary

Echo · 20 Oct 2015, 2:29 pm

Nick wrote:
Echo wrote:As Spigot said there is a section in Maze that I always notice smells like gas. It's on the way to the Camberwell Junction Gutter box. Kinda worried me the first time but since then I've gone back 3 or 4 times and noticed it's always the same.
With no lasting notable brain damage...

Naw thanks Nick. Love you too <3

longnecksmasher · 21 Oct 2015, 4:47 pm

There's a spot in the maze that smells like chinese food..

Unclehaggz · 22 Oct 2015, 7:39 pm

Will-043 wrote:cheaper to get a canary

Gotta love that old mining technique!!

UH

steamidge · 22 Oct 2015, 9:02 pm

spigot wrote:There's a little side tunnel in there that always smells like that (I've only done the drain twice). I wouldn't worry too much about it.

Awesome, thanks very much. I figured that it shouldn't be too bad but I just wanted to double check. The extra info and everything is greatly appreciated as well, I'll definitely be keeping that in mind when I explore.
Probably won't be doing any sewers either by the sounds of it haha (not sure why I would want to anyway)