Effects of breathing small amounts of natural gas for extended periods?

Does anyone know what are the effects of breathing small amounts of natural gas, over a long period? I did a search and couldn't find any info.

Several people (including myself) have noticed a slight smell of gas in my house, occasionally, in certain odd locations (like half way up the stairs) or just as you enter one upstairs room. I had Transco out but they couldn't detect anything. Still, I'm not convinced.

I've been suffering from extreme tiredness for several months, and wonder if it could be caused by breathing small amount of gas while at home.

My house is about 100 years old and has various old redundant gas pipes, imbedded in the walls and under the floors, but the only pipe which is supposed to be live is teh one going directly from the meter to my central heating boiler. And that is all at thoe opposite end of the house from where the slight gas smell has been commented on.

BTW, is natural gas heavier or lighter than air?

Many thanks,

Mike D Mike D

Reply to
Mike D
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I think it's harmless, unless there's enough to significantly reduce the oxygen concentration, but there would be no question of an incredibly strong smell.

Some boilers often emit some unburned gas from their flue when they light. Is it possible there's some boiler flue gas getting back in the house?

That could also be consistent with boiler flue gas getting back in the house.

Reply to
Andrew Gabriel

Tiredness and smell of gas.

It *could* be unburnt gas from the boiler, along with carbon monoxide.

If you haven't done it already, get that boiler checked very soon.

Reply to
dom

Is there a brick flue adjacent to the areas where you get the occasional smell? One (remote) possibility is that there has been some deterioration of the flue structure allowing flue products to percolate through the plaster and into the living space. Many terrace houses have a staircase which backs onto "next door". A possible problem might occur from next doors flue and the possibility exists that there was no leakage while Transco were present. I have in the past been witness to a case involving poor building practice allowing leakage into a bedroom from a coke boiler exhausting into a brickwork flue with gaps in the mortar and spacing, but concealed by plaster. Rare but it led to long term health deterioration until it was traced and rectified

Reply to
cynic

Several times I've thought I've had a gas leak. Each time it has been after SWMBO has 'creosoted' the fence. there seems to be a slight similarity with the smells.

Reply to
<me9

Old gas pipes can give of the smell of gas -- it's a powerful scent, and a little goes a long way.

Thomas Prufer

Reply to
Thomas Prufer

I don't know how deadly the stink additive is but none of the paraffins are noxious. Unvented, they seem to have an effect on driving ability though, no doubt, copious amounts of the assassin's drug of choice: hashish, might be involved there though.

All paraffins aka alkanes are heavier than air. They run from Methane at 4 carbon atoms through to Octane with ten, a volatile liquid through to turps at about 16 IIRC, all the way down to the really heavy waxes used in tarmac.

There is no limit to the length of the molecule chain. But the density remains about the same all the way through. I have no idea why.

The long strands seem to have no particular affinity -or more importantly aversion, for each other other than as liquids they are miscible and as solids their threads remain interwoven -hence demonstrating very little of a crystalline matrix.

It could be argued that hydrogen is the first one in this family but of course it would be the first in all the organic families of hydrocarbons and be a pointless inclusion except to say that hydrogen too is not noxious.

Reply to
Weatherlawyer

If the tiredness is a symptom of carbon monoxide poisoning, I believe a blood test can confirm that. If you see your GP, mention your suspicion.

Also the service pipe from gas main to meter, which they can't test with the usual pressure-loss test. Possibly it could be from a gas system next door, or gas mains in the street; less likely but it has happened.

BG, Transco ( or whatever they're called now) I've found to be utterly useless; they left a leak from their gas service pipes or mains (which they had known to be corroded) into my house, until I'd replaced my gas installation. Then they lied through their teeth about it. They change their name when the bad publicity accumulates to an unacceptable level.

I'm fairly sure it's lighter, but small leaks usually gets dispersed by air movements & convection rather than forming a layer on the ceiling. Propane and butane are heavier.

Reply to
Aidan

Naah. Methane's lighter than air, and makes up between 85% and 98% of gas...

Thomas Prufer

Reply to
Thomas Prufer

During RAF (Ground Defence training ) we were taught the mnemonic (used by the NYFD) ; ...

Vapor Density Mnemonics

To aid in remembering which gases are lighter than air some mnemonics or acronyms have been devised. A New York City fire officer around the turn of the century developed a well-known mnemonic for vapor densities. To train his fellow fire-fighters he used the term "HA HA MICE" to remember the lighter than air gases. The letters stand for;

H - Hydrogen A - Ammonia H - Helium A - Acetylene

M - Methane I - Illuminating Gases (old term for natural gas) C - Carbon Monoxide E - Ethylene

This acronym was useful for years ....

It's one of the reasons for instructing people , in burning buildings, aircraft etc to 'get down _Low_ and crawl.'

Reply to
Brian Sharrock

I don't think so, but that is a symptom of breathing in quantities of carbon monoxide. Which is present in the combustion gasses of a gas appliance. IIRC it's a simple test to check for CO in the blood so might be worth seeing your doctor. And get a competent gas engineer to check all the appliances you have.

Reply to
Dave Plowman (News)

density of air ~1.3kg/m^3

A single Carbon atom with 4 Hydrogen atoms around it density ~0.7kg/m^3

A chain of 8 Carbon atoms with 18 Hydrogen atoms strung along them. volatile liquid but for once you're right, the vapour density /is/ heavier than air at ~5.2kg/m^3 hence the vapour recovery being introduced at petrol stations.

Reply to
Andy Burns

Gas isn't meant to leak. If it is leaking, it's likely to be either significant enough to be a risk of explosion, or else it's coming from the exhaust of the boiler / gas fire not being vented properly. The second of these can also have a risk of CO along with it, and low levels of that can certainly give the symptoms you describe.

Reply to
Andy Dingley

What a dunce. Sack him!

Reply to
Weatherlawyer

Aren't those the same thing?

(I would have though illuminating gases would have more likely referred to man made coal gas etc)

Reply to
John Rumm

Natural gas as supplied for fuel is about 90% methane CH4, most of the rest being ethane C2H6 and a little CO2 and N2.

AFAIK the toxicity of Natural gas is quite low; the explosion hazard is much more significant long before the toxicity is an issue.

[Coal] Miners are exposed to methane at around 0.1-0.9% in air (more than than that and the electric gets turned off and work stops). Apparently breathing methane all day at those concentrations might give you a slight headache.

Manufactured gas, aka town gas, city gas or first family gases are extremely toxic as they contain substantial quantities of CO.

The OP should not worry about breathing tiny amounts of CH4. HOWEVER any smell of gas is unacceptable, a large leak smells just the same.

Reply to
Ed Sirett

Is the natural gas we have piped naturally in that mixture or is it blended that way for a reason?

Hence the futility of trying to gas yourself in the oven these days...! ;-)

(and that is without considering the effects of a flame failure device)

Reply to
John Rumm

Thanks to all for the helpful replies. The gas smell I and my vistors have commented on, always seems to be confined to very limited areas within the house, as though a cloud of it is hanging in mid-air. But if methane is lighter than air as exoplained in this thread, that seems to make it unlikely that it's gas we are smelling. On some days I smell it, some days I don't. It seems to make no difference whether the central heating is turned on. The boiler doesn't get used much for heating tap water either. If I close the door to the offending room, and go back in there after 24 hours, the smell has not built up, and may just as likely be completely absent.

I have ordered my own leak detector now, so I will be able to spend some time trying to trace it next time I smell it.

Thanks again.

Mike D

Reply to
Mike D

"Were" - there has been no town gas made in the UK since conversion to natural gas was completed in 1977.

Even before then, many of the old coal gas plants had been replaced by plants that used oil and other hydrocarbon feedstocks to produce a town gas substitute that contained very low levels of CO. It was mostly H2 and CH4, blended with inerts to give the correct calorific value and density to be compatible with exiting town gas burners. As with natural gas, the smell (mercaptans) had to be added afterwards.

Reply to
Ian White

It has to meet a lot of requirements, that were originally based on the gas that was available in the 1960s:

  • within a specified range of calorific value

  • within a specified range of density (along with the CV, this ensures that the gas will deliver a known amount of energy when metered through a nozzle - Google for "Wobbe number"or "Wobbe index")

  • not too much hydrogen (to avoid light-back)

  • not too much inerts (to maintain flame stability)

  • not too much heavier hydrocarbons (to avoid sooty flames).

Most of those requirements are inter-related, but it all started out quite easy because the standards had been written to match the gas. I don't know how much additional effort it requires using present-day feedstocks.

Reply to
Ian White

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