View Full Version : Safety Question

02-09-2005, 04:43 PM
Does the Oxy/Acet torch produce lethal amounts of carbon monoxide? ie. would it likely be deadly using one for short periods (how short?? ...maybe 20 to 30 min.) in a closed 2 car garage?

I took a welding course a few years back, and we used a cutting torch a lot indoors. Of course it was a much larger, industrial type building. I'm also not sure of any ventilation system present there if any.
(My garage has no forced ventilation system)

Since these free-standing kerosene heaters are routinely used in closed spaces, it creates some doubt as to the combustion by-products of the O/A process.

02-09-2005, 05:06 PM
As I understand it, if you've adjusted for a neutral flame you should have carbon dioxide and water as by products. Of course, the world isn't perfect so you'll have some carbon monoxide but it should be OK.

Wait until others with experience respond too before trying it out but if you really want to ask an expert, put a carbon monoxide monitor fairly close to your work area and let it tell you the answer.

3 Phase Lightbulb
02-09-2005, 05:06 PM
I think it's lethal if you stick the torch in your mouth. http://bbs.homeshopmachinist.net//smile.gif

I'm a little concerned too. I've been practicing my Oxy/Acetylene in a TIG class I'm taking at a local tech at nights. I've done 5 classes so far with 3 hours of O/A torch time each night. I've got about 30 more O/A hours before I'm moving on to TIG but I'll be 90% there on TIG when I get to it .


[This message has been edited by 3 Phase Lightbulb (edited 02-09-2005).]

02-09-2005, 05:20 PM
GET yourself a parakeet in the garage.

02-09-2005, 05:21 PM
Generally as long as the flame is burning blue with no little soot floaties it is complete combustion with no carbon monoxide produced.

3 Phase Lightbulb
02-09-2005, 05:27 PM
Well, it's not really the torch mixture that we need to be concerned with, it's the material that we're welding or cutting that is more likely to emit poisonous gases. I've been using copper coated filler wire, and some of the steel I've been welding together has a coating (probably light oil or who knows) to protect from rust... I'm more worried about that materials I'm working with...


02-09-2005, 05:35 PM
Certainly the other gaseous emissions from the materials involved are of interest, and could cause some health problems. But a buildup of CO, could render all health concerns moot.

Just what are the characteristics that make some fuels produce CO and some not? ...charcoal vs. wood, for example?

02-09-2005, 06:11 PM
The key is incomplete combustion of carbon. Not enough oxygen and you get CO instead of CO2.

02-09-2005, 06:36 PM
Yep, incomplete combustion.

02-09-2005, 06:38 PM
I once laid down to tig weld some items. Argon being heavier than air, collected /stayed in my lungs nearly making me pass out. Dizzy, I did't understand what was happening for a minute or two.

I was dizzy for about ten minutes. Bending over a few times and exercising for a few minutes cleared it up. No more brain damage than usual.

It is not a poison, but a asphixiant? spelling? I have worked around poisons also thou. One whiff will do ya with some of them. AND NEVER GIVE the ammonia spray bottle to a Dumb-arse who sprays it all over where ya are working with chlorine gas. It smokes alright, makes your gloves smoke and you have to take them off really fast. (wearing a scott airpack)

Worry will not get it welded, but you do have to look around to see what is happening. If you feel dizzy or abnormal, figure out why.


02-09-2005, 06:48 PM
3ph is right about being concerned about the material you are welding or cutting. Galvanized metals will make you very sick! If what your working on is emitting green fumes, clear out!

[This message has been edited by lugnut (edited 02-09-2005).]

Dave Opincarne
02-09-2005, 08:35 PM
Just having a blue flame is not the same as having compleat combustion. If there's a feather on the tip of the cone than it's still a carburizing flame. Can't recal off the top of my head but the reaction is a two part process. Theroticly you're supplying oxygen to the acetaline from the tank so you're not removing it from the room and as long as you have compleat combustion either from the ox supply or room air you'll end up with CO2 and H20, but a CO detector is cheap insurance.

Usual disclamers


02-09-2005, 09:17 PM
Where do you get a CO detector?

Michael Moore
02-09-2005, 10:00 PM
Metal fume poisoning is a definite hazard. However, at a local welding shop I found fume filter masks that can be worn under a helmet/goggles which do seem to help.

I braze weld with an inline flux tank, and after a period of that without the mask I can definitely taste it in my mouth for some time. The mask seems to help, though it doesn't completely eliminate the taste. Good ventilation is worth having, but don't have breezes blowing on the item being welded.

Get the metal clean, clean, clean. No oil, paint, plating, etc.

<Homer Simpson>Ummmm, cadmium fumes . . .</Homer Simpson>


02-09-2005, 10:01 PM
WalMart has nice, plug-in CO detectors, digital read out, for $19.95, brand is Nighthawk, division of Kidde Safety.

"Does the Oxy/Acet torch produce lethal amounts of carbon monoxide? ie. would it likely be deadly using one for short periods", that depends.

My rosebud heating head is the most used part of my O/A setup. Use it for heat-treat, bending, preheat for cast iron welding, etc. Mine is not a monster (1,000,000 btuh), just a little 100,000 btuh unit, big enough for most jobs. Like you, I wasn't concerned about CO, until my detector started beeping after only five to ten minutes of heating head use.

My shop is pretty large (2100 sq ft, and almost 20,000 cubic feet) so anything that triggers the alarm in a big shop is going to alarm faster, and be more dangerous in a smaller shop.

Now the overhead door is always open 2-3" and the exhaust fan is on whenever the O/A is burning, same as when I'm MIG or stick welding.

Barry Milton

Dave Opincarne
02-09-2005, 10:44 PM
Any place that sells smoke alarms will likley have CO detectors, they look very similar and there are combination units as well.


3 Phase Lightbulb
02-09-2005, 11:02 PM
I still think putting the torch in your mouth will cause the most harm..


Dave Opincarne
02-09-2005, 11:33 PM
No, putting it in your mouth would do the most harm, or is that good? Just joking, no flames please http://bbs.homeshopmachinist.net//biggrin.gif