Carbon Monoxide, A Surprise Finding

[GoodEnuff]

A few months ago, I had a non-vented propane heater installed to assist and as a backup for the electric baseboard heaters in this house. The propane heater is installed on a wall in the main living area. This is the only gas appliance in this house; everything else is electric.

What is interesting is that the CO detector was showing peak levels of 13-14 ppm, which according to one site is about the same amount produced by cooking on a gas stove. The detector audibly alarms at 30 ppm or higher. It has never alarmed. I check those levels frequently, clear the settings and it always went back to 13-14.

Then I quit smoking about two weeks ago. Guess what? The CO detector has read 0 ever since. And yes, I tested it and it is working.

 

[Michael Z]

Smoldering wood produces CO. And smoldering tobacco and paper too, it seems.

 

[horseless carriage]

Then I quit smoking about two weeks ago. Guess what? The CO detector has read 0 ever since. And yes, I tested it and it is working.

It was fifty-seven years ago at the age of twenty-two that I quit smoking. How stupid I was ever to start, but back then smoking didn't kill you and tobacco was smoked everywhere, even in courts during a trial. It was the stress of study as a student, that and probably peer pressure that got me started at eighteen.

What drew me to this post was the quitting of smoking. When I quit, twenty cigarettes of my favourite brand, cost a half penny short of two shillings. In today's UK decimal currency that would have been a fraction short of ten pennies. Looking up today's price of that brand I see a twenty pack costs sixteen pounds fifty pence.

Putting that into perspective the comparison price in pennies is. 1968: 20 cigarettes ten pence. 2025 a similar 20 pack of cigarettes one thousand six hundred and fifty pence. The price hike over the interim fifty-five years has been down to taxation. Tobacco tax increases are one of the most effective means of reducing tobacco use. It might seem unfair but ill health caused by tobacco is well documented. A smoker in the UK won't have to pay for their subsequent health care, well they do, but they pay for it in tobacco tax.

 

[Magna-Carta]

From my early days in college at the ripe age of 16, studying vehicle technology, along with engine technology, "CO" was often described as the result of "incomplete combustion". Propane, being a gas, generally burns quite efficiently, producing CO2 when combustion is complete. CO, on the other hand, is a byproduct of incomplete combustion and is significantly lower when burning propane efficiently.

A cigarette, however, is designed to burn inefficiently so that it lasts longer after lighting it. As a result, it produces significant amounts of CO -- most of which is inhaled, allowing it to enter the bloodstream. A smaller amount would have lingered in the air, which your CO detector picked up. That small amount in the air still being significantly higher than what would have been drawn into the lungs.

It makes sense to me that your propane heater didn’t trigger the detector so much, if at all, while your smoking did. And now that you’ve quit, the CO level has dropped to zero in your home, regardless of the use of the heater.

I suppose the activity is called "smoking" for a reason -- where there’s smoke, there’s usually CO from incomplete combustion.

 

[GoodEnuff]

Propane, being a gas, generally burns quite efficiently, producing CO2 when combustion is complete. CO, on the other hand, is a byproduct of incomplete combustion and is significantly lower when burning propane efficiently.

Yes. When using propane, I watch the flames. A blue flame is complete combustion. Most people who have gas stoves (propane or natural gas) know that the burner flame should be blue; if it is orange or yellow, there is a problem.

As much as I read about combustion and CO levels, nowhere could I find anything reliably solid about CO levels in room air where smoking has occurred.

Two months of using this propane heater and the CO monitor consistently read 13-14 ppm. I assumed it was coming from the heater. It wasn't until a few days ago, after two weeks of 0 ppm, that it hit me that it was the cigarettes causing it. That's the only change.

 

[Magna-Carta]

Two months of using this propane heater and the CO monitor consistently read 13-14 ppm. I assumed it was coming from the heater. It wasn't until a few days ago, after two weeks of 0 ppm, that it hit me that it was the cigarettes causing it. That's the only change.

It’s reasonable to connect the changes the way you did, but I think a lot of what we perceive as "correct" can depend on our personal experiences.

When I read about your CO levels, it makes sense to assume the heater might be the source, especially when seeing a reading on the meter. But, based on my own experience, I’d look at it differently. I grew up watching my parents smoke indoors, mostly in the living room, and I could see the faint cloud of smoke forming in the middle of the room. If they’d bought a propane heater and had a CO monitor back then, my first thought -- even as a child -- would’ve probably been that the CO was more likely coming from the cigarettes, not the heater.

Thankfully the house was big enough for me to find a room that had no cigarette smoke. Those experiences may have had some influence to drive me to never take up smoking.