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I just came here, looking for emergency advice because my CO detector is beeping. It makes me think that Wikipedia topics that are about emergency devices should begin with emergency instructions, in large type of what to do immediately. My two cents - David. —Preceding unsigned comment added by 99.246.84.235 ( talk) 13:47, 25 November 2007 (UTC) reply

So, how do they work, and is there some kind of makeshift one that one could construct from household items in a situation where a commercial one is not an option? That would be good info to include here. - GTBacchus^{( talk)} 02:08, 8 December 2005 (UTC) Actually though co is lighter than air, its diffusivity is high so it mixes in air rapidly. — Preceding unsigned comment added by 2405:204:70CF:F9D7:0:0:8A0:D0A1 ( talk) 16:20, 14 April 2019 (UTC) reply

I made the suggestion about not needing them on the ceiling into a stern warning. If you install them on the ceiling (unless they're specifically designed for it - most aren't) it could be deadly. = incorrect Carbon monoxide is not heavier than air - in fact it is slightly lighter as CO has the RMM of 28 whereas air is slightly more than this. It is therefore almost neutral density. However in a normal room, thermal convection current dominate transport of gases in a room. The ceiling is a relatively good place to have a CO detector as long as air flow from convectional currents in not affected and any boundary layer is overcome.

A ceiling mounted CO detector would have to be very sensitive in relation to a normal "near the floor" detector. NOT TRUE Does anyone have any examples? I've never even heard of a ceiling CO detector. Fracture ^Talk    06:19, 2 September 2006 (UTC). The reason why many CO detectors are not ceiling mounted is because semiconductor devices require mains power and therefore they need to be connected to a mains outlet and these are normally near the floor. reply

I'm confused--the article on carbon monoxide says it's lighter than air! -- Matt McIrvin 08:06, 21 September 2006 (UTC) reply

Yeah the density of CO is less than that of air, therefore its lighter than air (but not by much), this article is incorrect. Mr Bungle 09:26, 21 September 2006 (UTC) reply

Right you are. I've made the correction and added a reference. sinewave ^Talk    05:17, 24 September 2006 (UTC) reply

It should also be remembered that for a nearly neutral density gas such as carbon monoxide, in most normal rooms thermally induced air currents will be the dominant factor in the distribution of gas around the room. Although gas diffusion is a factor for the distribution of carbon monoxide, thermal air currents normally dominate. The positioning of the carbon monoxide detector should therefore reflect this. -(someone wrote sometime)

Although it is better to install the detector high rather than low, the most important thing is to not install it in a "corner", where the air might not circulate adequately. Also, the detector should be installed between the most likely sources of CO (a furnace) and the sleeping area, so that it will warn sleeping people, and wake them up. - 69.87.202.65 16:42, 23 August 2007 (UTC) reply

I would like to point out this article still incorrectly states that CO is denser("Heavier") than or equal in density to air. I agree "should be installed between the most likely sources of CO" and while I can't say anything about air currents, I think the best advice is to follow manufacturers specification. What I was taught is that CO's should be in the area of outlet to your waist on the wall in *GENERAL*. I wont push that though as I see it as being very much an opinion, with no real scientific backup. Magu ( talk) 06:47, 19 May 2008 (UTC) reply

Carbon monoxide weighs about 97% that of air, thus will eventually "float". However, almost all household alarms (the "detector" is but a component inside the alarm) use an accumulated effect for their detection and warning as CO at low levels over a long time is as dangerous as higher levels in just minutes. The proper location is in the open air (away from corners and furniture) but also away from doors to outside, windows, bathrooms and kitchens. High or low is not relevant except for digital units which should be at eye level for ease of reading. As well, the lifespan of alarms is based on the specific manufacturer's technology to maintain a certain level of calibration, thus most alarms have a 5 year life with a current maximum of 7 years for CO alarms (although 10 years is coming soon in Canada). Added May 7, 2012 --- Comirelo

This very impressive website not only reviews CO detectors, it has a serious, considered overview-review of reviews, Updated July 2007: http://www.consumersearch.com/www/house_and_home/carbon-monoxide-detectors/index.html If you are feeling brave, please try to add it to the article.- 69.87.199.142 23:16, 23 August 2007 (UTC) reply

Testing A Carbon Monoxide Detector

Most CO detectors have a test button that should be pressed once a week to confirm that the device is in operation. Detectors with displays can be tested with a known source of CO such as smoke from a cigarette or incense stick. Hold the CO source about 8-10 inches away and watch the digital display respond to the presence of even a small amount of CO. BUT an alarm will most likely not sound with this test.

There are CO detector test kits available, where CO detectors are sold, that provide a vial of high level of CO (1000 ppm) and a plastic tent to house the unit during the test. This test only proves that your detector will sound an alarm with a very high level of CO. [1] - 69.87.199.142 01:17, 24 August 2007 (UTC) reply

Changes In Test Standards

The standards organizations of Canada (CSA) and the United States (Underwriter's Laboratory or UL) have co-ordinated the writing of CO standards and product testing. The standards as of 2005 prohibit showing CO levels of less than 30 ppm on digital displays. The new standards also require the alarm to sound at higher levels of CO than with previous editions of the standard.The reasoning behind these changes is to reduce calls to fire stations, utilities and emergency response teams when the levels of CO are not life-threatening.This change will also reduce the number of calls to these agencies due to detector inaccuracy or the presence of other gases. Consequently, new alarms will not sound at CO concentrations up to 70 ppm. Note that these concentrations are significantly in excess of the Canadian health guidelines.

Detectors with a digital display and a history option can provide the true CO concentrations in a house. A low-level display would be useful for people with existing respiratory problems or for those who like to spot evolving problems, rather than having to wait for the situation to become serious. Low-level CO detection products are becoming commercially available. They will not be certified to CSA or UL standards, as these standards currently prohibit low level displays. [2] - 69.87.199.142 01:34, 24 August 2007 (UTC) reply

Isn't 35 PPM the point where bad stuff starts to happen? Pets dying, newborns dying, people with respiratory or heart/blood problems dying, etc. I know 25 PPM is the point where healthy individuals start having symptoms but it's less for others. If half your family is dead before a detector is *allowed* to go off are they really worth buying? How do you find a detector that displays low level amounts given this regulation? I want to troubleshoot why my family feels sick. 204.237.107.161 ( talk) 17:06, 22 December 2012 (UTC) reply

until recently, 100ppm/8hrs of work was acceptable. It's now 50ppm/8hrs (Ontario) In some factories, they have no choice. Propane tow motors can generate CO. Appliance (natural draft) venting only has to be below 100ppm. (condensing appliances often are higher) 35ppm takes a significant time to affect people and is unlikely to stay that low if an appliance is generating CO. — Preceding unsigned comment added by 66.49.131.188 ( talk) 06:54, 25 May 2015 (UTC) reply

Early designs were basically a white or beige element which would fade to a brownish or blackish color if carbon monoxide were present. As carbon monoxide related deaths rose during the 1990s, audible alarms became the norm. (Simple, reversible-color visual detectors are still available in 2007. [3])

It seems relevant to mention that the main makers of domestic detectors for the US market seem to be Kidde (brand Nighthawk) and First Alert. But I don't know if or how it might be proper to add this info to the article. - 69.87.199.132 16:40, 27 August 2007 (UTC) reply

This is a good assortment of industrial equipment: [4] which generally costs $100-500 -- and is only good for a few years. - 69.87.199.132 23:08, 27 August 2007 (UTC) reply

"The test button on a CO alarm only tests the battery and circuitry not the sensor"

Not True! the two main standards for these detactors in Euroipe and North America, EN50291 and UL, both make testing of the sensor for open circuit or short circuit faults mandatory. Ther test button will not ensure hat the sensor accurately detects CO (the only way to do this is by using a test gas, of course), but it will pick up 95% of sensor faults, if the detector is approved to one of these standards. —Preceding unsigned comment added by 86.139.90.136 ( talk) 13:11, 23 September 2010 (UTC) reply

I just discovered that my carbon monoxide detector has an "end of life" beeping mode, which sounds just the same as it's low battery warning mode. This raises the issue of disposal which is apparently subject to local code, likely a worthy topic to aid people in making the right choice on how to dispose of their "expired" detectors. —Preceding unsigned comment added by 74.66.83.101 ( talk) 21:09, 4 December 2010 (UTC) reply

Currently there are few locations that require recycling nor are capable of it. As of May 2012, British-Columbia has a recylcing program but in the rest of Canada, only regular household garbage can handle them. That includes smoke?CO alarms with the ionization which contains Americium241. --- Comirelo

The legal situation is only discussed in two states in the US. Does anybody know the current legislation about these else where. I'm particularly interested in Europe. — Preceding unsigned comment added by Grimley517 ( talk • contribs) 23:59, 26 December 2011 (UTC) reply

A survey of US laws by state is available at ncsl:CO-detectors-state-statutes - BAL 29/12/2013 — Preceding unsigned comment added by 172.2.68.87 ( talk) 05:33, 30 December 2013 (UTC) reply

The article says there are four, but only lists chemical strips, electrochemical cells and semiconductior types. — Preceding unsigned comment added by Testem ( talk • contribs) 08:55, 9 March 2012 (UTC) reply

For some unknown reason the sections got removed - I've reinstalled them  Ronhjones   ^(Talk) 16:24, 16 April 2012 (UTC) reply

So far, my (admittedly limited) ransacking of the web hasn't turned up anyone even ASKING the most important question, let alone answering same:

Here and now, in the second decade of the twenty-first century, is 7 measly years REALLY as good as this technology can get?

As an electronics technician for many decades, I'm a little skeptical any time industrialists claim an alleged "need" to periodically replace somewhat-expensive items that don't seem like they should even HAVE a "decay rate" - always reminds me of John Lovetts' "Pathological Liar" character from SNL - "Yeah! You, uh, have to replace 'em, yeah, um, every few years, because, er, uh, that's the best we can do right now! Yeah, THAT'S the ticket!"

I'm invariably left wondering: are manufacturers REALLY providing technology which "goes the limit" of what is ACTUALLY, practically "do-able" at this point in history, or have they simply "pulled-back" their research to a level which assures, NOT the optimum protection of my family, property, wallet, etc., but, rather the optimum protection of their continuing profit margin, through an ongoing form of CONSUMER FRAUD known as "Deliberate Obsolescence"? (...NOT "Planned Obsolescence", mind you - that's a whole different animal, and a perfectly valid industrial concept. "Deliberate Obsolescence", on the other hand, is the malicious manufacture of "Landfill By Design": technology which flagrantly WASTES raw materials, energy, time, etc., and UNNECESSARILY destroys itself, just a little bit, every time you use it and/or every minute of every day, so that you have no choice but to give them "mo'money, mo'money, mo'money" nearly every time you turn around.)

Has anyone seen a salient, believable answer to this point?

The Doctor Is On ( talk) 21:08, 22 April 2014 (UTC) reply

I wonder if the manufacturers have thought through the legal implications of intentionally disabling a piece of safety equipment. If a householder chooses to continue to use a detector past its advisory last-use date, that is their own decision and their own risk. However, time-bombing a detector to cause a noise nuisance at a specific date and thus force the owner to remove the battery, could be seen as a felony if it leads to an otherwise avoidable death. -- Anteaus ( talk) 17:30, 30 January 2017 (UTC) reply

Limited lifetime of CO sensors seems technologically plausible to me, so far. Considering a reaction-with-metal, color-changing sensor. If it reacts with CO, it will probably react with S, CN, or CNS _irreversibly_. Then ambient concentrations of those will degrade the sensor over time. The electrochemical cell I just found in my self-deactivated detector looks like it has a getter-chemical packet taped over its aperture. This is a consumable; and when depleted the cell can then start to degrade. The only near-permanent technology I can think of would be a 5-micron mid-IR laser with a resonant gas cell, stimulating faint acoustic resonance to be detected by microphone. Too expensive and too big for consumer alarms. Better sensing techniques may well turn up, but I'm not surprized they are not here yet. jimswen ( talk) 23:26, 11 December 2017 (UTC) reply

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"Smaller concentrations can be harmful over longer periods of time while increasing concentrations require diminishing exposure times to be harmful."

Shouldn't this read either:

1. Smaller concentrations can be harmful over longer periods of time while increasing concentrations are harmful over diminishing exposure times.

or

2. Smaller concentrations can be harmful over longer periods of time while increasing concentrations require diminishing exposure times to be safe.

As written it doesn't seem to make sense. -- Jack6128 ( talk) 21:34, 10 December 2016 (UTC) reply

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