Talk:Carbon monoxide poisoning

Completely wrong on what CO does to hemoglobin
This article is completely wrong and does not site a source. CO binding to hemoglobin while it blocks O2 binding is not the reason it causes poisoning. The cause for poisoning can be demonstrated by the following. An anemic individual possesses 1/2 the normal hemoglobin as a normal person. Fatal CO poisoning occurs when only 1/2 the O2 binding sites are taken up by Oxygen. Hence the major error in this article. CO binding allosterically shifts hemoglobin to the R state preventing the release of bound O2 to oxygen starved tissues.

Please fix the article. Ingenpedia is so difficult to edit anymore and these factual errors are not getting fixed by knowledgable individuals imho. — Preceding unsigned comment added by 128.32.166.162 (talk) 00:43, 18 April 2012 (UTC)

i think the patho is wrong too. it does not affect cytochrome oxidase and neither was mentioned in the reffered sourse. — Preceding unsigned comment added by Abgbotak (talk • contribs) 12:26, 25 September 2019 (UTC)

Strength of Ligands
Though CO and Cyanide are both strong ligands why do they proceed in two parallel routes in their mechanism for poisoning the human body? --Curieous 09:58, 14 October 2007

Another possible treatment for CO poisoning
I found this on the "iron" article:
 * ''Humans also use iron in the hemoglobin of red blood cells, in order to transport oxygen from the lungs to the tissues and to export carbon dioxide back to the lungs. And iron is an essential component of myoglobin to store oxygen in muscle cells.


 * The human body needs iron for oxygen transport. That oxygen is required for the production and survival of all cells in our bodies.

This seems like taking an iron tablet would help. -Usernamefortonyd

Maybe to combat the effects of chronic low-level exposure. Taking iron isn't going to help if most haemoglobin has been rendered useless by acute CO exposure, the body isn't going to make new haemoglobin fast enough. Also remember IN:NORM0ffx 11:09, 12 October 2007 (UTC)

Then you have to deal with the effects of iron overload as well; iron is pretty toxic (like most minerals) when outside it's normal dosage; case in point, haemochromotosis. For the treatment to be effective, the iron would need to be a form easily and quickly absorbed into the bloodstream, and capable for readily forming a stable, non-toxic complex with CO. The iron in an iron tablet is not in such a form. —Preceding unsigned comment added by 58.161.19.90 (talk)

Resolving the disputed tag
I've left a message with User:Physchim62 asking him for information on the disputed tag. --Arcadian 16:58, 9 December 2005 (UTC)
 * The following paragraph was queried on the Reference Desk:
 * "With chronic low-level exposure, similar neurologic injury may occur. Carbon monoxide acts as a potent neurotoxin, creating irreversible lesions in the brain's white matter (i.e., the myelin sheath). Such lesions, which are similar to those found in multiple sclerosis, can result in severe cognitive impairment."
 * As with most of the article, its source is unclear; I have however managed to track down the paper, which appears to be Penney, D. G.; Verma, K.; Hull, J. A. (1989). "Cardiovascular, metabolic and neurologic effects of acute carbon monoxide poisoning in the rat". Toxicol. Lett. 45(2/3):207–13. As the title suggests, this study concerned an acute exposure in an animal model, not chronic exposure in humans.
 * The use of the term neurotoxin is more than ambiguous: such neurological damage may not be solely related to primary anoxia, but other animal studies suggest that secondary hypertension, secondary acidosis and elevated blood glucose levels are also involved (Penney, D. G. (1990). "Acute carbon monoxide poisoning: animal models: a review". Toxicology 62(2):123–60.)
 * "The effect of prolongued exposure to low levels of carbon monoxide [in humans] is still a very controversial subject. It seems however that a long term toxic effect on the cardiovascular system cannot be excluded." Institut national de recherche et de sécurité (1996). "Oxyde de carbone". Fiche toxicologique n&deg;. 47, 6pp. (PDF, in French) And how can you discuss possible chronic effects without noting that heavy cigarette smokers have HbCO levels of 10% or over (compared to 1–2% for non-smokers in the countryside: Source Sax's Dangerous Properties of Industrial Materials)
 * Unfortunately, such imprecisions seem common throughout the article, which should be completely rewritten from trustable sources: I certainly don't object to carbonmonoxidekills.com being an external link, but if it is really the only source then we should just start again from scratch.
 * Physchim62 (talk) 10:24, 10 December 2005 (UTC)

Reduction of O2 delivery isn't often relevant?
The reduction in oxygen delivery (DO2) caused by carboxyhaemoglobin is seldom relevant, but often quoted as the mechanism of the observed tissue hypoxaemia. For example, if total Hb is 15 g/dL and CarboxyHb is 33%, then this still leaves 10 g/dL of normal OXYHAEMOGLOBIN. So at worst, CO poisoning has caused a mild functional anaemia. This can hardly be responsible for tissue hypoxia to any degree. Whilst it is true that the P50 of this oxyhaemoglobin is left shifted, this has a minor effect in the context of tissue acidosis which  mostly overcomes it. The principal mechanism of tissue hypoxia is poisoning of cytochrome oxidase, with failure of electron transport and reduction of molecular O2. The value of measuring Carboxyhaemoglobin is that it merely serves as a useful marker of exposure to CO.

Symptoms?

I personaly think a section describing the symptoms of carbon monoxide poisoning would enhance this article.
 * Yes. Also, some information on prognosis. How fast do the symptoms of minor poisoning fade with time (or do they), what treatments are used, and how effective are they?--Srleffler 23:07, 12 February 2006 (UTC)
 * I can answer this from experience, as I used to work with the stuff and suffered minor poisoning on a couple of occasions. First symptoms are lethargy and/or a headache. Treatment is to remove the source of intoxication (I used to take myself off home for the afternoon), recovery is complete within hours. I'll see if I can come up with more citable sources for the article. Physchim62 (talk) 00:21, 13 February 2006 (UTC)

Recommeded reading: Henry CR et al: Myocardial injury and long-term mortality following moderate to severe carbon monoxide poisoning. JAMA 2006; 295: 398-402.

CO and heart disase
Missing from this article seems to be a discussion of the link between CO and heart disease. --Badger151 19:56, 16 April 2006 (UTC)

Carbon Monoxide toxicity
Should the term carbon monoxide toxicity redirect to this site?

Does Carbon Monoxide poisoning have any relation to cancer? Such as Bladder Cancer or Lung Cancer?

There appears to be a contradiction of facts or at least a begging explanation, as to why in the section labeled "Sources" it lists undiluted cigarette smoke as having 30,000 ppm YET, in the section "Toxicity" a concentration of 12,800 ppm results in unconsciousness after 2-3 breaths. So, why aren't more smokers falling over unconscious? I think there is an exaggeration of some kind in one of the two places.

Here is an article that says cigarette smokers exhale between 10-50ppm of Carbon Monoxide. Carbon Monoxide in Cigarette Smoke

At the very least, the statement that undiluted cigarette smoke has 30,000 ppm of Carbon Monoxide is misleading and should be removed unless it is explained or justified. —Preceding unsigned comment added by 76.107.145.71 (talk) 19:45, 26 October 2008 (UTC)

Out of place
Smething seems out of place here

Because carbon monoxide binds to haemoglobin several hundred times more strongly than oxygen, its effects are cumulative and long-lasting, causing oxygen starvation throughout the body. Prolonged exposure to fresh air (or pure oxygen) is required for the CO-tainted hemoglobin (carboxyhaemoglobin) to clear. Carbon monoxide detectors for homes are now readily available and are increasingly being required by municipal building codes.

The last sentence seems very out of place and I think it should be moved to a different section (I tihnk it is already mentioned somewhere else anyway).Father Time89 05:10, 7 November 2006 (UTC)

Palladium compounds
"The carbon monoxide can be easily detected by the filtering paper impregnated by the solution of the palladium chloride. Carbon monooxide reduces the palladium monoxide to the black metallic palladium. This reaction is very sensitive."

Well, which one is it? The oxide or the chloride? —The preceding unsigned comment was added by MikaelRo (talk • contribs) 19:09, 6 December 2006 (UTC). --MikaelRo 19:11, 6 December 2006 (UTC)

Carbon Monoxide Poisoning - Long Term Effects
The long-term effects of Carbon Monoxide poisoning seems to have been left out of the general Carbon Monoxide catagory. One might survive CM poisoning but what then? The University of Kentucky did a study on this and found that men my experience impotence and women may experience premature sexual aging. Cardiovascular disease and Parkinson's disease have also been cited. When a person is CM poisoned it's the equivalent if being at the bottom of a lake with no air except that this time it is being caused by a poison. Linda Dohse 00:51, 19 January 2007 (UTC)

Hb tetramer effect
In the "Toxic mechanism" section under "Hemoglobin" the article says:

Because hemoglobin is a tetramer with four oxygen binding sites, binding of CO at one of these sites also increases the oxygen affinity of the remaining 3 sites, which interferes with normal release of oxygen. This causes hemoglobin to retain oxygen that would otherwise be delivered to the tissue.

How does that cause–effect relationship work? Seems like a CO molecule would knock one iron of the four out-of-play, having no effect on the other three. The statement gives a cite of, but I don't see any discussion of Hb tetramers or of enhanced Hb affinity for O2 during CO exposure in that article. DMacks 17:41, 11 April 2007 (UTC)

The binding CO to a haem iron atom causes the haemoglobin chain to distort. Because a haemoglobin molecule is a tetramer, the distortion of one protein chain will cause distortions in the other chains, which prevents the release of oxygen. —Preceding unsigned comment added by 58.161.19.90 (talk)

Real-world concentrations
Please add some real-world concentration numbers, typical CO ppm ranges: -69.87.199.142 00:20, 24 August 2007 (UTC)
 * atmosphere: baseline, suburban, urban, in traffic, upper atmosphere
 * candle flame, kerosene lantern flame, natural gas burner flames
 * internal combustion exhaust: before and after catalytic converter, diesel

"Several natural sources of CO of both biological origins have also been identified but their contributions to urban atmospheric concentrations are thought to be small. Background levels of CO (resulting from natural and technological sources) found in relatively unpolluted air range from 0.025 to 1.0 ppm. Urban carbon monoxide is produced primarily by motor vehicles.

Because motor vehicle traffic is the major source of CO, daily concentration peaks coincide with morning and evening rush hours. The worst carbon monoxide problems are found where large numbers of slow moving cars congregate. These problems are further aggravated when they occur in a "street canyon" situation. When there are large amounts of slow moving traffic in a street canyon situation, with the wind blowing perpendicular to the street, carbon monoxide can be trapped in the canyon and build up to unhealthful levels.

CO problems are usually worse in winter because: 1) cold weather makes motor vehicles run dirtier and requires more combustion for space heating; and 2) on winter nights a strong inversion layer develops in the atmosphere, that traps pollution near the ground, preventing it from mixing with cleaner air above."

"No standards for CO have been agreed upon for indoor air. The U.S. National Ambient Air Quality Standards for outdoor air are 9 ppm (40,000 micrograms per meter cubed) for 8 hours, and 35 ppm for 1 hour." "Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher."

"undiluted cigarette smoke contains about 30,000 ppm of CO, undiluted warm car exhaust about 7,000 ppm, and the chimney of a home wood fire about 5,000 ppm. Clean countryside air contains about 0.02 ppm of CO. The smoke from one pack of cigarettes, if distributed uniformly throughout an average sized house, could result in a CO concentration of up to 14 ppm.

An average healthy person at sea level is just barely affected by prolonged exposure to concentrations of 9 ppm, but the presence of other pollutants aggravates the situation, and respiratory and cardiac problems pose an increased risk. Chronic exposure to high concentrations of CO (30 to 100 ppm), such as in a poorly vented garage, can lead to long-term deterioration of the cardiovascular system." (1983) -69.87.199.142 01:09, 24 August 2007 (UTC)

Air quality data
It would be great if there were one integrated website people could go to for current or historic carbon monoxide measurement data for any particular locations. This is the best I've been able to find so far: -69.87.200.24 23:24, 28 August 2007 (UTC)
 * International Air Quality

Here is a map for New England, and real 1979-2006 annual data: For Massachusetts, here is a map of the monitoring stations: And here are the Annual Air Quality Reports: -69.87.200.24 23:34, 28 August 2007 (UTC)
 * http://www.epa.gov/NE/airquality/co.html
 * http://www.mass.gov/dep/public/netmap.htm
 * http://www.mass.gov/dep/air/perfor01.htm

Access to US EPA annual database: -69.87.203.68 21:55, 29 August 2007 (UTC)
 * AirData : Access to Air Pollution Data

Heating appliance design, installation, operation and maintenance requirements
Another item that may be worth writing in to this article is government requirements concerning the design, installation, operation and maintenance of heating appliances that burn fossil fuels.

For example, unflued propane-burning portable heaters that were built since the 1980s would bave an "oxygen-depletion" sensor device which shuts the heater off if there is little oxygen burning in the room. This may also be true for recently-built kerosene heaters. Similarly, there are mandatory flueing and room ventilation requirements in most jurisdictions for installation of gas-fired appliances, especially room heaters. Similarly, people are encouraged to have their gas appliances serviced at regular intervals so that they have proper fuel-air burning ratios and ventilation requirements.

SimonMackay (talk) 15:39, 15 May 2009 (UTC)

GA
Page looks fairly good. A bit of work and it should be GA. Doc James (talk · contribs · email) 02:35, 19 December 2009 (UTC)


 * A few things though:


 * 1) A bit about how it is "the great mimicker"
 * 2) How the season affect its occur.
 * Doc James (talk · contribs · email) 02:38, 19 December 2009 (UTC)

Saturation
I'm having some trouble understanding this image. If I get it right, it says: The higher the Oxigen pressure is (horizontal axis) the higher the oxigen concentration in blood (vertical axis), with a non-linear correspondence. But why would carbon monoxide shift this toward the left now? I would expect that the oxigen pressure must be higher than normal for the blood to still bind some oxigen, which means the courve shifts to the right. --PaterMcFly talk contribs 14:44, 4 February 2010 (UTC)

Nazis and CO
If the article is going to mention CO as an instrument of suicide then it would be consistent to mention it as an instrument of murder. Nearly all the victims of Operation Reinhard died of CO poisoning. Could anyone trying to exclude this fact from the article please explain why. Thanks Hardicanute (talk) 15:37, 28 April 2011 (UTC)Hardicanute
 * This article is a Good Article and therefore has to comply with requirements of IN:WIAGA. That statement about the Nazis' use of CO is unreferenced and is therefore IN:Unverifiable (the requirement is not one of "true" or "false": it is a potentially challengeable statement and therefore must be verifiable). Sorry, but I'm removing it, you may re-add it provided that you provide a IN:Reliable source. If you are unsure of that that means, please ask and I will help. Pyrotec (talk) 19:13, 28 April 2011 (UTC)
 * P.S. Ingenpedia is not regarded as a reliable source. Operation Reinhard is mentioned above, and there is a statement about the use of CO in it, but the CO statement has no verification. Operation Reinhard is a Start class article, so the lack of verification is perhaps less likely to be challenged, but it could be. Pyrotec (talk) 21:40, 28 April 2011 (UTC)

I quite agree about Wikipaedia not being a 'reliable source', at least as far as history and biography goes, though we might be using term in slightly different senses! I thought the Nazis use of CO was verging on 'common knowledge' but I'll see if I can find a reliable source.Hardicanute (talk) 00:34, 29 April 2011 (UTC)Hardicanute
 * Use of Car exhaust for killing people in the third reich before the use of Zyklon B is common knowledge. There exist tons of books in any respectable library.

Try this: http://www.nizkor.org/hweb/camps/chelmno/sonderdruck.html 178.78.75.150 (talk) 10:54, 13 November 2014 (UTC)
 * And Nizkor is a reliable source? Hardly. If you put it in, please also point to reference that the homocidal gassing claims are in dispute. 105.0.2.201 (talk) 12:13, 13 November 2018 (UTC)

Carbon Monoxide detection
I have reverted the original title because the content is clearly and mainly about detection of the gas. This is also a help to those who wish to install and use such detectors, and the original title is too nebulous to be useful.Peterlewis (talk) 11:46, 29 August 2011 (UTC)
 * Public health is a better name as it deals with other issues including the safe operation of machinery. Doc James (talk · contribs · email) 11:55, 29 August 2011 (UTC)

Update
This article needs to be updated using secondary sources per IN:MEDRS. There are too many primary sources at this point when many secondary sources are available.-- Doc James (talk · contribs · email) 18:45, 30 December 2011 (UTC)

A question about coal-gas ovens
"Before the 1960s most domestic gas supply in the United Kingdom was coal gas (alternatively known as town gas), which in its unburned form contained high levels of carbon monoxide." I take this to mean that someone could commit suicide by inhaling coal-gas from an oven even if no gas was burnt - ie there was no pilot light or other flame to burn the gas and so create carbon monoxide by combustion. The gas itself would kill you from the high levels of carbon monoxide it contained? Thanks for the clarification. Cheers. Span (talk) 03:12, 16 February 2012 (UTC)
 * Absolutely. Ala Sylvia Plath. If you tried that these days, you'd only look very silly for a few hours, awake but uncomfortable (until the room filled with gas and perhaps it DID blow up from some ignition source not the pilot light). Of course that presumes you'd extinguished the pilot AND then found a way to override the pilot light shut-off valve, which keeps gas from flowing when the pilot isn't lit (Plath's oven presumably didn't have one). Or had a 1950's oven that nobody had put a modern pilot valve in. Blowing yourself up with natural gas is a lot easier with a gas fireplace than a stove. S  B Harris 19:48, 16 February 2012 (UTC)

Thanks for the clarification. So in the 1950s, say, unburnt coal gas would be sufficiently toxic but the pilot light would have to be out or the gas would ignite? Span (talk) 20:12, 16 February 2012 (UTC)
 * Yes. And in addition, those ovens didn't have a valve that automatically shuts off the main gas with no pilot lit, see Pilot light. S  B Harris 20:18, 16 February 2012 (UTC)

Pain Experienced By Victims
Does Carbon Monoxide cause the level of discomfort and pain associated with suffocation? Or is the pain and discomfort felt by someone who dies from Carbon Monoxide poisoning merely one of drowsiness and then death (after they lose conciousness)? I searched the article for "pain" and "nociception" but found nothing. AnInformedDude (talk) 00:05, 5 November 2012 (UTC)
 * It's a "silent killer", people fall a sleep in rooms where, say CO is building up to to a faulty gas burning appliance, and just die in their sleep. Pain would disturb sleep. Carbon dioxide causes discomfort and pain associated with suffocation when in gets into "percentage levels". Pyrotec (talk) 15:37, 2 December 2012 (UTC)

Review
... in AJRCCM: 10.1164/rccm.201207-1284CI JFW &#124; T@lk  11:05, 2 December 2012 (UTC)

With catalytic converters?
What is the typical concentration in automobile exhaust with modern catalytic converters? The article only mentions the concentration without, and I couldn't find a ready source. -- Beland (talk) 01:23, 22 February 2013 (UTC)


 * Some countries/regions have limits and cars for instance have to be tested (cars/light vans over three years old currently need an annual test in the UK - so there is a CO limit for petrol cars/light vans with spark ignitions - see here and there are different limits for diesel engines). Pyrotec (talk) 15:29, 22 February 2013 (UTC)

Heart damage
20% of cases have elevated cardiac troponins. They do worse than those who don't. Primary source so probably needs to be corroborated by a secondary source before it can be included 10.1136/emermed-2012-202152 JFW &#124; T@lk  21:05, 17 February 2014 (UTC)

How look body of person 1 hour after death from carbon monoxide poisoning?
In the article is about red-cheeked and healthy, I've seen video from Odessa, Ukraine, the corpses look black faced, but the rest of the body is white. The cause of death was stated to be monoxide poisoning from fire. It's possible the faces are dark red and look black due to low light condition. Is the cherry-red limited only to face? http://www.youtube.com/watch?v=rsViVUr1CbY — Preceding unsigned comment added by 24.193.229.70 (talk) 18:58, 6 May 2014 (UTC)

Straight Up Hyperbole

This was written in the Signs and Symptoms section: "Inhaling even relatively small amounts of the gas can lead to hypoxic injury, neurological damage, and even death." Everything else that was provided in that section had a source, except for the information I just quoted. I have always valued Ingenpedia for its unbiased information free from emotional rhetoric and tone. The line that I quoted reeks of erroneous information and deliberate sensationalism. If it is true-- even in rare cases, then a source and a follow up of the likelihood and/or events and conditions that would lead someone to succumb to hypoxia after inhaling small amounts CO would be appropriate.
 * Thanks for the tip. ""Inhaling even relatively small amounts of the gas can lead to hypoxic" -->  ""Inhaling the gas can lead to hypoxic"--Smokefoot (talk) 14:28, 24 August 2014 (UTC)

Template produces poor PDF output
PDF output using Google Chrome's built-in distiller produces poor results with this page. (Use the Ctrl P command in Chrome to preview). Issue may be with the template used or (more likely) the the way content was entered (coded) and saved by the contributor. For example, when printing this article with Google's PDF printer, the info-box content spreads to about 80% of the printed page's width. The info-box column should not exceed 50% on a portrait layout (45% appears nicer and looks closer to a WYSIWYG web page view), Note that the font size should not dynamically scale up or down to fit a page; font size of the main-body text content should be about 12 points on outputted PDF page(s); it is the images and table cells that should dynamically scale up or down to fit the info box in order to maintain the two-column Ingenpedia layout. NOTE: many of the chemistry-related articles have this issue Printchecker (talk) 06:27, 23 September 2014 (UTC)

The Holocaust vs History
This is starting to get a little too close to warring. I'm going to put a comment on the main page requesting editors do not change the heading until consensus is achieved. So:

Should the title of the section be The Holocaust or History?

Holocaust (weakly) IMHO the paragraph is entirely about the Holocaust and should be labelled as such. If the paragraph were extended to include other aspects of the chemical then history would be the appropriate title. Martin of Sheffield (talk) 12:18, 21 October 2016 (UTC)

I agree: the section is solely about The Holocaust and should be so labeled for clarity. 5.81.207.79 (talk) 19:06, 21 October 2016 (UTC)
 * Have added further details about the history of CO poisoning. Doc James  (talk · contribs · email) 19:59, 21 October 2016 (UTC)

External links modified
Hello fellow Ingenpedians,

I have just modified 4 one external links on Carbon monoxide poisoning. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20130502012946/http://gassaferegister.co.uk/advice/being_gas_safe.aspx to http://www.gassaferegister.co.uk/advice/being_gas_safe.aspx
 * Added archive https://web.archive.org/web/20130305145343/http://www.lawlib.state.ma.us:80/subject/about/carbonmonoxide.html to http://www.lawlib.state.ma.us/subject/about/carbonmonoxide.html
 * Added tag to http://ehpnet1.niehs.nih.gov/members/2002/110p1051-1055devine/devine-full.html
 * Added archive https://web.archive.org/web/20111212171534/http://www.bt.cdc.gov/disasters/psa/co.asp to http://www.bt.cdc.gov/disasters/psa/co.asp
 * Added archive https://web.archive.org/web/20150312065135/http://www.scer.gov.au/files/2012/03/EMR2-QRA-Final.pdf to http://www.scer.gov.au/files/2012/03/EMR2-QRA-Final.pdf

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).

Cheers.— InternetArchiveBot  (Report bug) 00:33, 15 November 2016 (UTC)

Hyperbaric oxygen
Following the to-and-fro editing of the value 83 or 87 for the half life is it possible for a citation to be attached to the value? I tried to access the end of sentence reference but as a non-medic such information is kept hidden behind a paywall, I've modified the citation to note this. Superficially the calculation looks flawed, but I do notice the approximation sign. Might I suggest changing to something along the lines of: "... half life of carbon monoxide to 23 minutes, roughly a third of the 80 minutes for oxygen at regular atmospheric pressure" if 83 is indeed the correct figure? Regards, Martin of Sheffield (talk) 08:50, 23 November 2017 (UTC)

External links modified (January 2018)
Hello fellow Ingenpedians,

I have just modified one external link on Carbon monoxide poisoning. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added tag to http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=2403894
 * Added archive https://web.archive.org/web/20150924002528/http://www.esv.vic.gov.au/Portals/0/About%20ESV/Files/Gas%20use%20reports/2004AddendumtoOverseasandAustralianStatisticsandBenchmarksforCustomerGasSafetyIncidents.pdf to http://www.esv.vic.gov.au/Portals/0/About%20ESV/Files/Gas%20use%20reports/2004AddendumtoOverseasandAustralianStatisticsandBenchmarksforCustomerGasSafetyIncidents.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 13:21, 22 January 2018 (UTC)

Units
The usage in the article does not seem to specify, is ppm being used on a mass or volume basis? --2001:9B1:EFD:9400:4C54:D8B2:AE5C:8E68 (talk) 10:12, 3 July 2020 (UTC)
 * Good question. To a first approximation though they will be the nearly the same.  The mw of CO is 28, the average for air is around 29, therefore at the same temperature and pressure the volume and mass ratios are very close. Martin of Sheffield (talk) 10:46, 3 July 2020 (UTC)