Carbon Monoxide Poisonous?

Greg_26

I’m curious about carbon monoxide poisoning. Is it a poison gas or does it kill you like drowning? Water can’t be considered a poison but it can kill you if you try to breath it. Something like ammonia gas or cyanide gas I would considered poisonous. I think you die before you suffocate.

Also, if carbon monoxide is poisonous then why don’t I die when I cook with NG. I don’t have a hood vent and I’ve accidentally left my oven on all night before yet I don’t die? An unvented or poorly vented water heater or furnace apparently can kill me. And then there are the “vent less” NG heaters. How does that work? I’ve also seen “blue flame” heaters?

I’m trying to separate the hyperbole from the facts. Any thoughts?


Thank you,

Greg

Dave Yates (PAH)

It is dwowning - in a sense

Carboxyhemoglobin - your red blood cells drown in CO.

http://www.contractormag.com/articles/column.cfm?columnid=137

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Bill Nye_2

Greg ,

.. if you are serious, do a search for carbon monoxide facts. Start with this link, copy & paste

http://www.homesafe.com/coalert/cofacts.htm

You can find about 1,000 links.

It has a lot to do with exposure time and the concentration of CO gas. Really, what you don't know could kill you. It is a tasteless, colorless, odorless gas.

.

You claim water isn't poisonous because you can drink it, even if it kills you when you breathe it. CO is the same way; drinking it is harmless.

Also, just like you can spray a little water up your nose, you can breathe a little CO without ill effects.

Greg_26

Thanks

Perhaps I was being a bit lazy. I Googled Carbon Monoxide Poisoning and did get 1000s of links - Ugh! I read how atoms interact and how many people die. I guess I was looking for a little less science lession and a little more "real world average Joe" explanation. Maybe I didn't fish through enough links but I didn't read why a vent-free heater does not kill me and a poorly vented water heater does. I didn't read why stove doesn't kill me and my furnace does.

But thanks anyway,

Greg

Mark Hunt

Here are a few good links Greg

CO Experts

CO HQ

There are two types of Co poisoning, acute and chronic.

Acute poisonings are the ones that make the news. "Family sent ot hospital" or "3 dead from CO poisoning". Acute poisoning is when CO levels are high enough to cause immediate damage.

Chronic poisonings are caused by continuous exposure to lower levels of CO. This type of poisoning is misdiagnosed 99% of the time. The medical community just isn't looking for it.

So the answer to your question is this, any time you operate your gas stove or oven, unvented, you are being exposed to CO. Without testimg the equipment, no-one can tell you what the levels of CO are. The UL listed CO alarms available on the market today will not alert you to the low levels of CO associated with Chronic Poisoning.

If you have any further questions, please feel free to post them here. It is a subject very close to my heart.

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

t. tekushan

CO

I've often wondered about those unvented fireplaces. You're getting into a high enough BTU input that the potential of a significant concentration of CO exists in a tight room, it seems to me.

I've wondered this since those things give me a headache under those circumstances.

Hey, I'm into the old Servel gas refrigerators, which put out very little CO when they are clean and adjusted properly. I use a good CO detector that gives you a readout, not just an alarm when its almost too late. I can tell you that a dirty Servel that's misadjusted can set off the alarm in the room, that with a teeny 2300 (max) bunsen burner.

What happens to these fireplaces when they get old and dirty?

(BTW, I vent the Servel, just in case. Fantastically quiet and efficient frig!)

Greg_26

OK, Chuckles, I'm intrigued.

How does a "vent free" heater put out less CO than a "standard" heater (what ever that is) when the BTUs are the same. Why is a "vent free" heater just a "spritz of water in the nose" and not "a pair of cement shoes in a lake".

WHY DOESN't IT KILL ME?!?! Why doesn't it put out more or as much CO, or does it and there is something else going on? This is what I don't understand?

Greg

PS To the other poster that supplied the other links. Thanks. I hope to visit them soon.

Mark Hunt

\"Vent free\"


Unless a test is performed, NO-ONE can say what is producing more or less CO. And BTW, there is no such thing as "vent free" anything that burns vents. Those "vent free things" just vent into your house as opposed to up a chimney.

CO is produced by incomplete combustion, so anything that burns here on Earth produces CO since there is no complete combustion here on Earth. But there may not be enough CO present to actualy kill you, but there may be enough to cause other problems like Parkinsons or Alzheimers or Congestive heart failure. The list for Chronic CO poisoning is quite long.

You don't die because you haven't been hit with a lethal dose. That number depends upon the person. Infants and elderly are overcome more quickly than a healthy, middle-aged adult. That is just the way it is.

Buy a real CO alarm and then see what happens. You may be suprised.

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Al Corelli - Agix Associates

Do you have any info on those Servels?

I am interested in their operation.

Al Corelli
agix1@optonline.net

Mark Eatherton1

Google Servel Refrigerators

Theres LOTs of resources out there on the web, but use caution. The old ones have been recalled due to CO production. Follow this link. http://www.recall-warnings.com/cpsc-content-98-98145.html

ME

Bill Nye_2

o2 sensor

Greg , the ventless appliances are required to have an Oxygen depletion sensor.I just read that in another post somewhere. Our "Air" has about 21% or 20.9% oxgen , when the sensor reads 18.something it shuts the appliance off.

so that is how it may have a lesser chance of killing you if something malfunctioned. With any kind of poison, how much and how long you are exposed are the factors

Greg_26

Interesting

For the lack of a better term I will continue to use the term "vent free" for heaters that don't vent directly to the out side.

Having said that, and assuming that the laws of physics remain constant I still don’t understand what the difference is between vent-free heater and a vented heater. Three things are needed for combustion: Oxygen, fuel, and heat. Both heaters use these three things. Is it that they both produce the same amount of CO but one has an oxygen sensor as a safety mechanism or does one just produce less CO? That doesn’t sound right that the oxygen sensor is all that separates the two. If CO is produced by incomplete combustion of the fuel then the vent free heaters must do a better job of completely burning the fuel. So then is it the ratio of oxygen to NG that makes for a better and more efficient burn and thus a more complete burn and also less CO. Is there some sort of carburetor on these devices that makes for a better ratio? Is there a correlation between the color of the flame and how complete the fuel is being burned? Is a blue flame more efficient than a blue flame with white and yellow tips, or just a yellow flame. I recall reading that with a propane torch for sweating copper the blue part of the flame is the hottest. Hotter would seem to be more efficient. Also, I understand that there are degrees of danger. Many things can kill you in large doses but are unnoticeable or even beneficial in small doses. I think that can be said for many, many things in life.


Thank you,

Greg

Unknown

Greg if you send me

an e-mail with your postal address I will send you a FREE manual on Carbon Monoxide.

Unknown

Right on Mark

I started my career with the gas company servicing gas refrigerators. They need to be serviced once a year and most people do not know how to set up the old refrigerators. I still have all the service manuals on both Servel and later Whirlpool gas refrigerators.

When set up incorrectly or when they get dirty they can produce very high levels of CO.

Unknown

Greg, let me try to give you a simple

explanation of the difference or maybe better the sameness of vented vs. un-vented.

First of all both operate basically the same as far as combustion and products of combustion are concerned. The difference is this the vented allows exhausted products of combustion to be removed from the space. In that sense their efficiency if you will is less (more heat up the vent). The unvented is 100% efficient as far as that goes. Why because all the heat goes into the space instead of some of it up the chimney.

The products of combustion from the un-vented heater are now in the room. One of those products is CO2 which is an extinguishing agent, which can displace the O2 needed for proper combustion or in fact be pulled into the combustion process thus cooling or quenching the flame (this produces CO). This then becomes the concern for safety reasons and the need for a ODS application.

You mentioned earlier cooking with NG and not being overcome. The answer is thousands of homes have gas ovens and use them eveyday and most of the time the CO output is very low. BUT and this is a big BUT the potential is always there. Do a combustion test on your oven you may be suprised at how high the CO reading will be. The ANSI standard allows 800 PPM air free. It should however be operating as close to ZERO as you can get it.

Blue flames are definitely the best and correctly adjusted gas flame. However a "blue flame" does not mean that an unsafe CO condition could not be present.

So I hope I answered your question which I hope is based on really wanting to know and not just for the sake of arguement.

If it is knowledge you are seeking on this subject I would be more than happy to assist you in this area. I recommend Jim Davis training classes, also Bacharach and of course my own classes.

John Conway

CO for the masses

Thanks to all, especially Mark, for the recurring discussion on this topic. The dangers are huge and too often casually dismissed. CO is deadly. The consumer grade detectors seem to be junk. Here is a nice fresh anecdote.

I work for a small non-profit providing emergency assistance. This past Friday an elderly man came in seeking our help converting his heating from stand-alone kerosene space heaters to (unvented) propane. Seems he had collapsed and nearly died - neighbors dragged him out & called EMS. We're working on a VENTED heater for his old house. He DID have a CO detector in his home. He still doesn't believe me about CO produced by any combustion.... He did admit that his pet bird turns brown in the winter. (Yeah, I realize that's soot, but talk about canaries in the mines.... Arrgh!)

Unvented heaters ought to be outlawed in enclosed places. Shoot, they're poisonous in open areas!

Bob Harper

VF fireplaces and CO

Keep in mind all poisoning is dose over time. A short exposure to high concentrations may not be as bad as a long exposure to low levels.

As for VF gas fireplaces, they are listed to ANSIz21.11.2b. The ODS is basically a finely tuned standing pilot that is sensitive to the ambient O2 levels. If a VF is located in a confined space where it cannot receive proper ventilation, the room O2 can drop. The theory is, as long as you have enough O2, you shouldn't be making CO--more on that in a minute. When the room O2 drops to about 18.5%, the flame spead of the pilot has slowed sufficiently to the point the flame has advanced past the thermocouple causing it to shut down. VFs are finely tuned equipment with very little field serviceable parts. You cannot change just a thermocouple and you cannot field convert them from NG to LP or back. When they are properly installed to the listing( in the lab), they burn cleanly enough to pass the ANSI Stds., which btw allow for 200 ppm CO air free. However, as pointed out, these units need regular maintenance and cannot be fiddled with. Homeowners rarely clean them and rarely call for service. They rearrange the logs, put embers on the burners and use them in rooms full of all sorts of aerosol nasties. There is big difference btw in vitro testing vs. in vivo. The VF industry has spent tons of money on in vitro testing but almost none on actual field testing. We now have documented cases where homes have suffered serious moisture issues from these things. They also stink and shut off with the slightest lint on the pilot's primary air hole. They are a P.I.A. Hearth & Home Technologies, the largest Fp mfr. turned their back on selling VF(Est. $26 million/yr in 2003). If you're still not convinced they are a problem, go to: www.aventfreefireplaceattorneyforyou.com to read up on their evils and find a lawyer to sue the bums who sold and installed it.
FYI, on a properly installed set I routinely find a minimum of 26ppm air free in the fumes right off the burner. I would check the stack but I'd have to shove the probe down my throat...
HTH,

Mark Hunt

Excellent post Bob


Thanks!!

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Greg_26

Thanks Everyone!!!

Thank you all for trying to help me understand. I have a much better graps of the basic concepts.

This is something I’ve been curious about a long time and some recent events sort of brought up more questions. On the same day a few weeks ago a friend of mine got a new vent-free heater and I also read about a small family that was rescued from a house suffering from carbon monoxide poisoning. It was a problem with the water heater. The paramedics responded and got them out of the house and treated them with oxygen. All survived.

This started me thinking about all the NG appliances in my house. Were they all essentially the same or were there fundamental differences in the way they burn NG? I pictured a scenario where the local utility company comes out to relight the pilot of the water heater. He walks in to the kitchen were I’ve been cooking a turkey for 4 hours on a gas stove with no hood and says, “Hmmm, that smells good”. He then walks past my vent free heater and warms his hands a little, “Ahhh, boy that feels good”. Then goes to look at my water heater and freaks out because the vent is a little askew. He tells me we all could die and has to cut off the gas until it is fixed and inspected.

Does anyone else think that is a little odd? Does anyone else think that there are some inconstancies here?

I should note that the little scenario above could never happen to me because I live in California and vent free heaters are not legal yet (I say “yet” because I will never underestimate the power corporate America has over government). My friend her in Californai did buy a vent free heater. The funny thing is, he bought it from Northern Tool and they shipped it out. It arrived with a broken part so he contacted the manufacturer for a replacement. The manufacturer said they couldn’t ship parts to California because their product was illegal. He returned the heater to Northern Tool and they shipped a new one. More inconstancies.


Greg

Bob Harper

More CO errata

Last weekend, one of my managers almost didn't wake up. He awoke somehow around 01:10 a.m. smelling oil fumes. luckily, he got his wife and dogs out, shut down the furnace and aired the place out. They all had splitting headaches (dogs, too?) Anyway, they refused to go to the ER and get a carboxyhemoglobin level and it took 3 days for the symptoms to abate.
His nozzle sprayed out non-atomized oil causing the heat exchanger tubes and entire vent to block with soot. The cad cell still saw flame so it allowed the unit to continue firing. BTW, his hard wired CO alarm failed to sound because besides being almost 10 yrs old, one of the wires was loose! Somebody likes him because he should have awoken dead. It just goes to show the false sense of security with those hardwired alarms. He never tested it in 7 yrs he had the house and it came with it. I explained how sensors have a life span, that those old sensors were really crummy, and to buy several REAL CO alarms. He bought Nighthawks....Maybe he isn't over the CO yet, huh?

Mark Eatherton1

Tell us more Bob...

You're quite knowledgeable and well spoken. What do you do for a living if you don't mind my asking?

ME

Rudy

More info on unvented (or room vented) equipment

Found this some time ago, make some interesting points:
http://www.chimneysweeponline.com/hovfsci.htm

Steamhead

They are already illegal in some cities

Baltimore is one such city. We won't touch an unvented heater anywhere, except to disconnect and remove it.

Greg, where are you located? One of us should be near you who can test your equipment so you know for sure how well it's working. Today's digital combustion analyzers are absolutely amazing- you can see everything right on the screen, and a knowledgeable contractor with this equipment could just save your life. If you're in the Baltimore area, get in touch with me.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Bob Harper

laughing

Mark, I'm a Regional Field Operations Manager for Hearth & Home Technologies (Heatilator, Heat&Glo, Quadrafire) fireplaces M-F and I run a chimney repair business nights & weekends. I reline a lot of heater flues. I also teach for the Nat'l Fireplace Institute and I'm in the Standards Technical Panel at UL for my area. Part of my duties at HHT is product liability investigation and training. That, and I'm a swell guy....;-)
Bob

jim sokolovic

Bob, if you care...

to provide more of your thoughts from your above post - regarding the theory "when you have enough O2, you shouldn't be making CO", it would be of great interest. Thanks for your informative postings!

Jim Davis_3

CO poisoning or asphyxiation

When CO is in the air our blood will absorb it 200 times greater than oxygen, which reduces the amount of oxygen in our blood. The brain and heart need approximately 80% of the oxygen from the blood as it circulates. Any shortage will cause permanent damage to cells and tissue. Whether symptoms are evident or not, the damage is being done, quickly at high levels and slowly at low levels. Low level CO exposure over time leads to the development of Memory Loss(Alzheimers), Parkinsons, or Heart and Respiratory disease. Loss of sight, loss of hearing, loss of hair, multiple chemical sensitivity are just a few things that low level CO exposure has been found to be responsible for causing. What might be strange is that vented appliances poison and kill more people than unvented. The biggest reason for this is unvented are designed not to vent. Vented appliances are required to vent, but are not tested in the field to do so and are designed to continue to operate even if they are not venting. How many times have we read that an appliance with a plugged flue hurt someone? Why aren't appliances built to shut down? When I teach contractors to fix this problem so this unsafe condition cannot occur I get accused of modifying equipment designs.
The color of the flame is the biggest misconception anyone can have and has led to many poisonings and deaths. Anyone thinking that a blue flame is a safer flame is a danger to society.
As far as the equipment you have been operating, you have just been lucky so far, but then do you really know that you haven't suffered any permanent damage? Also oxygen depletion devices do not detect the level of CO an appliance is producing and guarantee minimum safety. Only testing by Certified CO contractors maximizes safety potential.

jp_2

simple answer

for one, basic chemistry says if you have abuntant amounts of O2 you will have complete combustion.

also I think in a controlled lab experiement, clean burner, etc... you see basically the same thing.

jp_2

simple answer

thats just basic chemistry, if you have abundant amounts of O2 you get complete combustion(on paper). you only get CO when recombining carbons can't attach to enough nearby oxygens.

todd_6

CO from ovens

After moving into a rental townhouse equiped with natural gas, I noticed something. When ever the oven would be started, the CO detector I have started showing readings above 0, but after it ran awhile, the numbers would go back to 0. I am assuming incomplete combustion initially caused this to happen. Makes me wonder. Food for thought.

Rudy

Also keep in mind

With regards to the digital display on a UL2034 approved alarm, UL does not require any degree of accuracy in the display, in fact, the GRI report on the performance of CO alarms found that the readouts "seemingly displayed random numbers".....

Go figure....

Jim Davis_3

High Oxygen

The key to clean combustion is getting fuel and air to mix and getting it hot enough to burn. Too much air can actually hinder this process as easily as too little.

jp_2

Bob explain please??

Bob,
is the oxygen dropping from 21% to 18.5% based in a glass box, that is, no new air entering the system?

its seems that the CO will climb extremely high before it displaces 2.5 % of the rooms oxygen ? it should also displace 2.5% of the nitrogen or becoming 5% of the rooms air composition?

if 1/2% oxygen is displaced by CO, isn't that like 5,000ppm CO?

also, if you are measuring 26ppm CO off the burner, what are you measuring on the other size of the room?

please explain?????

jp_2

too much O2

mr davis?
would this being happen mainly on the fringe areas of the flame front? I can see if too much O2 is surround the fuel, micro area temperatures could be reduced, thus not splitting enough O2 apart? or am I out on a limb here?

Mark Eatherton1

Thanks Bob...

and welcome to the Wall. Thanks for sharing your knowledge.

ME

Bob Harper

more combustion fun

The whole problem with these lung vented appliances is theory. They are not basing their claims on reliable field findings. When you set up a VF appliance in the lab under ideal conditions, you can get it to burn clean enough to meet the ANSI std. Note, I didn't say burn clean. Any luminous flame has some degree of incomplete combustion and therefore, CO along with unburned fuel, soot, aldehydes, NOx, and the like.

What actually happens at the molecular level when carbon is oxidized is it forms CO. Then, if there is sufficient O2 present along with over 1,300F, it forms CO2. However, if the temps. are high but insufficient O2, you start making all sorts of funky compounds, esp. para and acetylaldehyde, which gives the exhaust a characteristic odor. BTW, most combustible gas sniffers will hit on aldehydes so not all hits are gas leaks. I've had numerous "hits" that turned out to be CO. Always follow gas sniffer hits with your CO meter, just in case.

Switching gears for a moment, ya'll discussed too much O2 as a problem. I would clarify that in terms of too much air, as in secondary air. While we adjust the air shutter on atmoshperic injection burners for a nice blue flame that doesn't lift off, flashback, or yellow tip, we still have secondary air around the burner to consider. This is what gives fireplaces their characteristic yellow flames. We allow excess secondary air to mix with the flames near their tips. This is termed a diffusion flame as opposed to a premixed flame. This does several things: It cools the flame to where we start losing complete combustion, which =soot& CO. The soot particles are still very hot so they incandese or glow thus the visible yellow luminous flame. This air also disrupts the normal plume of gases giving the flame a pretty flicker. Now, allow this flicker to cause the flames to impinge on the decorative logs we put in our Fps and you have cooled the flame so we're back to soot & CO. The challenge of the hearth industry is to walk the razor blade of a pretty yellow tipped flame with blue bases that doesn't gunk up with soot. I'll discuss soot testing in another post, if you're bored and want to hear it.
Bob

Thanks for the kind words from Mark & Mark. I have enjoyed lurking on The Wall and already I've learned a bunch from ya'll.

Mark Hunt

There was a post here


a while back about raising boilers off of the floor that applies here.

Boilers with no flame shield below the burners will do exactly what you mention when raised off of the floor. Secondary air is increased and you can watch the pretty yellow tippped flames flickering away. I have watched the flame go completely yellow if you caused any air movement near the boiler.

Try doing a combustion test on one of those puppies! If you breath, the numbers change!

I have found no cases where VF appliances have been linked to a poisoning or death, but I still would not sell one. As you mentioned, all that has to happen is for someone to re-align the logs and the numbers will go to hell in a hand basket. I would not put my trust in an ODS since it does not offer protection from CO.

But if you consider that ovens are allowed to produce 800ppm and there is no code requiring them to be vented, we get a good idea of how screwed up the industry attitude about CO is. That standard hasn't changed since it came about. I believe that was in 1927?

Always good to discuss this stuff. When you set things on fire for a living, you better know what the fire is going to do.

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Greg_26

Ah ha!

[quote]
But if you consider that ovens are allowed to produce 800ppm and there is no code requiring them to be vented, we get a good idea of how screwed up the industry attitude about CO is. That standard hasn't changed since it came about. I believe that was in 1927?
[quote]

So I'm not crazy for asking these questions! There is something screwy here. Why didn't anyone mention this when I first started asking? The science talk is very interesting and I've hung on every post, but this is what I was asking about!!

Greg

Jim Davis_3

Your explanation would account for the reason excess O2 on atmospheric burners would increase. In class I set burners for 12-14% Oxygen(if they don't already come from the factory that way) and then ask students what will happen to the CO reading if they add fuel. In all cases the CO readings actually drop.

Mark Hunt

No, you are not crazy


the industry is.

Take a look at how many CO stories I've posted under the CO 2004/5 thread. That oughta' get you thinking.

If I had a dime for every old wives tale that exists concerning CO, I would be a wealthy man. The truth of the matter is that while CO poisoning is the number one cause of accidental poisoning deaths in north America, it gets relatively no attention until someone dies or has to be hospitalized.

I posted a an e-mail I received last night from a couple that we did some work for. The day I met them they were sitting in their kitchen drinking coffee with an LP oven going full blast and the oven door was open. They were trying to get heat into the kitchen to thaw some pipes that had frozen. I thought I walked into a suicide attempt. They never considered what could have happened, and we did get a CO reading when we entered the home.

Just because something meets a "standard" that does not guarantee that it is safe. You are only protected when you have a monitoring device that actually works. There are only two that I know of, CO experts and NCI's low level monitor. Everything else is junk, and I mean JUNK.

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

jim sokolovic

This info. is very...

clear to me, and I appreciate the time you all have spent to explain it. Thank you!