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

In article ,
Mike D writes:

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.

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.

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.

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?

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.

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

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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.

On 30 Jun, 22:03, " wrote:
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.

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

On Sat, 30 Jun 2007 21:37:46 +0100, Mike D wrote:

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.

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


Thomas Prufer

On Jul 1, 7:58 am, Thomas Prufer prufer.pub...@mnet-
online.de.invalid wrote:
On Sat, 30 Jun 2007 21:37:46 +0100, Mike D wrote:
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.

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

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.

On 30 Jun, 21:37, Mike D wrote:

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.

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 the 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.

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.

BTW, is natural gas heavier or lighter than air?

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.

On Sun, 01 Jul 2007 00:23:53 -0700, Weatherlawyer
wrote:

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.

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


Thomas Prufer

"Thomas Prufer" wrote in message
...
On Sun, 01 Jul 2007 00:23:53 -0700, Weatherlawyer

wrote:

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.

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


Thomas Prufer

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

http://www.firehouse.com/training/hazmat/training/2001/12_vapor.html

extract
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 .... /extract

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

--

Brian

In article ,
Mike D wrote:
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.

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.

--
*Some days you're the dog, some days the hydrant.

Dave Plowman London SW
To e-mail, change noise into sound.

On 01/07/2007 08:23, Weatherlawyer wrote:

All paraffins aka alkanes are heavier than air.

density of air ~1.3kg/m^3

They run from Methane at 4 carbon atoms

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

through to Octane with ten,

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.

On Sat, 30 Jun 2007 21:37:46 +0100, Mike D
wrote:

Several people (including myself) have noticed a slight smell of gas
in my house,

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.

On Jul 1, 10:00 am, Andy Burns wrote:
On 01/07/2007 08:23, Weatherlawyer wrote:

All paraffins aka alkanes are heavier than air.

density of air ~1.3kg/m^3

They run from Methane at 4 carbon atoms

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

through to Octane with ten,

What a dunce.
Sack him!

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.

In message . com,
" writes
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.

Err ...

"I had Transco out but they couldn't detect anything. Still, I'm not
convinced."


--
geoff

In message . com,
Weatherlawyer writes
On Jul 1, 7:58 am, Thomas Prufer prufer.pub...@mnet-
online.de.invalid wrote:
On Sat, 30 Jun 2007 21:37:46 +0100, Mike D wrote:
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.

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

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

One carbon atom

I think you need to rethink your organic chemistry - it's ****ed

--
geoff

Brian Sharrock wrote:

M - Methane
I - Illuminating Gases (old term for natural gas)

Aren't those the same thing?

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

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Mon, 02 Jul 2007 01:58:33 +0100, John Rumm wrote:

Brian Sharrock wrote:

M - Methane
I - Illuminating Gases (old term for natural gas)

Aren't those the same thing?

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


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.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

Ed Sirett wrote:

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

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

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

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)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sun, 01 Jul 2007 17:18:27 +0100, Andy Dingley
wrote:

Several people (including myself) have noticed a slight smell of gas
in my house,

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.

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

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

"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.


--
Ian White

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

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

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.


--
Ian White

In article ,
Mike D wrote:
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 had a smell which I thought was gas. Turned out to be a dead rat...

--
*Stable Relationships Are For Horses.

Dave Plowman London SW
To e-mail, change noise into sound.

On Tue, 03 Jul 2007 01:02:31 +0100, "Dave Plowman (News)"
wrote:

I had a smell which I thought was gas. Turned out to be a dead rat...

That's interesting... my cat *has* been known to bring dead mice into
the house. All I need now is an electronic dead-mouse finder! It took
me ages to find the last one. It eventually turned up in a coat
pocket, of all places. I still can't imagine how it got there. Funny
how mice keep cropping up in this thread. First 'ha ha mice', now
'dead mice'...

Mike D

On Mon, 02 Jul 2007 20:38:09 +0100, John Rumm
wrote:


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

It takes so long, you may as will light up a cigarette while
waiting...

Mike

My wife rang me at work a few week back saying there's a strong smell of gas
in my son's bedroom. To be on the safe side I bought a CO monitor/alarm on
the way home as the only source I could imagine was the boiler flue about
10ft from his window maybe getting sucked in through an airbrick or ? I got
home and it did smell like gas so I 'paid a visit' before putting batteries
in the monitor, the smell of gas was increased by me letting out the coffee
I'd had at work earlier! she'd put a load of bleach in the loo! it really
did smell like gas..... the monitor has been all over the house btw and it
reads 0ppm everywhere even on top of the boiler....

Also, interestingly, to test the meter it says to use a joss stick! close up
it should read 10ppm! wonder how unhealthy a handfull in a room would be ?

Pete

In message , Mike D
writes
On Mon, 02 Jul 2007 20:38:09 +0100, John Rumm
wrote:


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

It takes so long, you may as will light up a cigarette while
waiting...

Even that prolly wouldn't be much of a problem

it's only explosive in a concentration of between 5-15%


--
geoff

On Tue, 03 Jul 2007 19:16:23 GMT, raden wrote:

It takes so long, you may as will light up a cigarette while
waiting...

Even that prolly wouldn't be much of a problem

it's only explosive in a concentration of between 5-15%

Ah, but if the subject's head was inside the oven..... KABOOM!
(-:

Mike

In message , Mike D
writes
On Tue, 03 Jul 2007 19:16:23 GMT, raden wrote:

It takes so long, you may as will light up a cigarette while
waiting...

Even that prolly wouldn't be much of a problem

it's only explosive in a concentration of between 5-15%

Ah, but if the subject's head was inside the oven..... KABOOM!
TISH !

you should read the warning on the packet "Smoking kills"


--
geoff

"Thomas Prufer" wrote in message
...
On Sat, 30 Jun 2007 21:37:46 +0100, Mike D
wrote:

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.

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


Thomas Prufer

Methane is odourless so they add a 'smelly'. I think the additive is Ethyl
Mercaptan (Ethanethiol) and its a ridiculously low concentration as that
stuff is so smelly. When I worked in a lab years ago, someone threw 5
millilitres down a sink and the building had to be evacuated due to the
nauseous affect of the pong. Neighbours around the site were phoning British
Gas reporting smell of gas.

Paul

In article ,
"Paul C" writes:

Methane is odourless so they add a 'smelly'. I think the additive is Ethyl
Mercaptan (Ethanethiol) and its a ridiculously low concentration as that
stuff is so smelly. When I worked in a lab years ago, someone threw 5
millilitres down a sink and the building had to be evacuated due to the
nauseous affect of the pong. Neighbours around the site were phoning British
Gas reporting smell of gas.

Imperial College in the early 1980's, or did someone else do that too?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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

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

MOST natural gases contain significant ethane mixed with the
methane, though the proportions do vary. (Exception - natural gas produced
by the biological decomposition of organic matter can be essentially pure
methane. But practical gas sources in Western Europe are the result of
natural catalytic cracking, so produce a spread of output compounds
depending on the feedstock and the conditions of cracking.) Ethane is
readily available onshore (and offshore in many cases, from co-processing
of other parts of the field), so mixing to produce the desired blend for
the consumer network is not a major problem.
What happens with re-gasifying LNG (at places like Milford Haven),
I don't know. I could see real arguments going both ways for keeping the
gases pure, or for keeping the gases blended.
--
Aidan
Aberdeen, Scotland
Written at Wed, 11 Jul 2007 00:43 +0100, but posted later.