Oily Rag Fires

[Charles]

I am probably the last one to know about this, but I learned that folded or waded up cloth or paper towels that have natural plant oils (linseed, cottonseed, tung etc) on them will often generate enough heat due to oxidation of the oils to have spontaneous combustion of the cloth or paper and a fire will result.

My Step-Son who is a Fire Marshal was touring my shop and told me he investigates several fires a year that are caused by this source. Such oily rags should be;

1. Spread out to dry and allow any heat generated to dissipate.. or
2. Stored under water..or
3. Stored in an air tight container.

Petro based oils are not subject to this.

This is good information for those of us who finish gunstocks with linseed or tung oil and use cloth or paper to clean up spills and a mess. I am just passing this along, in case I am no the only doo-doo that hangs around here.

[JerryB]

Thanks for the good info, will check out my gun rag pile.
My grandson just got back from your part of the world Friday night, went down with our pastor for a revival close to McAllen.

[C. Cash]

Thanks for the reminder Charles. Good info to keep in one's head, as these fires do happen in just such a way. I use Nitrile gloves when I'm applying linseed. After I'm done, I put the rag in my palm, make a fist and then pull the glove off over the small linseed soaked rag. The glove is turned inside out with the rag inside. I tie the wrist opening up like a balloon sealing up everthing inside and thus no O2. Just something I do with Linseed or Tru-Oil.

[Ray Newman]

Yup, spontaneous combustion is nasty.

I place my oily rags, gloves, etc., in an old GI metal ammo can and let them sit there, then take them all out to the gravel drive and burn them.

[AJMD429]

For those who think this is just a rare or 'theoretical' thing - I can honestly say I've seen it first hand.

I had just gone out to the barn (visible from our balcony) to get a nice cold beer out of the refrigerator, and returned to the house and invited my wife to sit and relax (something she rarely does) a minute on the balcony. Fortunately, she did, and no sooner had we sat down, that I noticed the beginnings of some 'mist' coming around the corner of the barn, and assumed I'd left the refrigerator door ajar, or perhaps bumped the freezer door open a bit. I wasn't inclined to get right up and go downstairs and across the driveway to remedy the situation, having just popped open the brew, but upon watching it, it got to be a LOT of 'mist' and unlike cold 'fog' from a freezer, it was going UP...

By the time I bounded out there, the trash can was melted and on fire along with its contents. I had not placed anything 'fresh' in that can for probably days, either.

We got the fire out, thankfully.

That's one of the times it's hard not to believe God was looking out for my sorry butt; I guess he's got more work for me to do, or maybe just to do the same stuff I've been doing until I finally get it right. (...that's why they call it 'practicing' medicine, you know... )

[Mike D.]

This year, some friends and mountain neighbors lost their family cabin of 70+ yrs. The person they had hired to stain the new deck put all the rags and stain in the shed. A few days later, away it went. A passing off duty fireman saw the flames and called it in. The crew had to come 20 miles up the canyon, drive down a narrow access road, walk across a swinging bridge and fight the fire. The cabin and 1/2 acres of surrounding forest was lost, but they kept the fire from getting up the hill and away. The next week we walked down to see them and everyone hugged and cried. My wife took their kids down by the river to play and we sat and stared at the remains of their family summer home. I took no pictures out of respect for them. The really sad thing was the fire was entirely preventable. Now, they have a $50,000 bridge to nowhere. That is what the new bridge cost them 3 yrs ago. They do plan to rebuild, but it won't be the same.

[vancelw]

I am probably the last one to know about this, but I learned that folded or waded up cloth or paper towels that have natural plant oils (linseed, cottonseed, tung etc) on them will often generate enough heat due to oxidation of the oils to have spontaneous combustion of the cloth or paper and a fire will result.

My Step-Son who is a Fire Marshal was touring my shop and told me he investigates several fires a year that are caused by this source. Such oily rags should be;

1. Spread out to dry and allow any heat generated to dissipate.. or
2. Stored under water..or
3. Stored in an air tight container.

Petro based oils are not subject to this.

This is good information for those of us who finish gunstocks with linseed or tung oil and use cloth or paper to clean up spills and a mess. I am just passing this along, in case I am no the only doo-doo that hangs around here.

# 3. should be changed to a metal container with a metal lid. And rags should not be allowed to accumulate. Cotton and linseed is the worst combination, but dirty rags of any sort should not be kept around. While rare, spontaneous combustion can occur in rags with a high moisture content, oil not necessary.

The old adage is a clean house seldom burns.

[20cows]

I was not aware of the difference in petroleum and plant based oils in this regards.

[octagon]

I learned this lesson 1st hand 17 years ago in my guitar shop. I had placed 8-10, 4:4in squares of red rag in a pile on a concrete floor. They all had linseed oil on em. While at my repair bench one day I smelled smoke (not my cigar). Turning around I saw a little smoke coming from the rags, while I watched a few minutes, the pile caught fire. This shop was not very hot either. Scary!

[missionary5155]

Good morning
Thanks also for the info. You here about these fires... Some yeras ago I got rid of the "trash can" by my bench and use the simple plastic bags every store uses to pack purchases. I hang the bag on a nail. When the bag has enough weight to start to appear heavy stressing the single plastic loop handle, out is goes. Maybe God preprovided that safty factor for me. Maybe I need to investigate IF even that method is safe for combustable rags.

[Hobie]

Every shop I worked in had a can with a lid (or several) especially for storage/disposal of oily rags. No difference was made between oil types. Too confusing. Oily? Into the can it goes unless you're are using it.

[Chas.]

Paint thinner (mineral spirits) will do it also. It doesn't have to be oil.

[Idiot]

I was not aware of the difference in petroleum and plant based oils in this regards.

There is no distinction between oils. One of the first lessons you will get in mechanic school is how to handle oily rags (and there ain't nobody wiping linseed oil off of their manifold ). My garage gets upwards of 120 degress in the summer. I use mechanics paper towels and throw them away after each job and make sure all cloth towels are hung up and not collected together in some container. When it comes to fire, one must be very careful.

Good topic Charles.

[Hobie]

I was not aware of the difference in petroleum and plant based oils in this regards.

There is no distinction between oils. One of the first lessons you will get in mechanic school is how to handle oily rags (and there ain't nobody wiping linseed oil off of their manifold ). My garage gets upwards of 120 degress in the summer. I use mechanics paper towels and throw them away after each job and make sure all cloth towels are hung up and not collected together in some container. When it comes to fire, one must be very careful.

Good topic Charles.

Your comment pointed up my omission of the fact that the cans have lids (to deny air/Oxygen).

[Ben_Rumson]

This was about the first thing we were taught in any of the shop classes as well as Art classes.. The old man kept the compost in a covered 50 gal barrel to stop fire too

[Swampman]

A linseed oil rag generates it's own oxygen so it's combustion temp lowers until it burst into flames. Being in an air tight can won't stop that. It will keep it from burning out of control.

[Noah Zark]

I use non-woven lintless synthetic towels for staining and wiping-type finishes, and drape them over a metal rack to "dry" prior to disposal.

Other rags with mineral oil get placed into a 50-cal ammo can with a mess of surface rust that I sanded down and painted JD yellow for the purpose.

Noah

[vancelw]

I was not aware of the difference in petroleum and plant based oils in this regards.

There is no distinction between oils. One of the first lessons you will get in mechanic school is how to handle oily rags (and there ain't nobody wiping linseed oil off of their manifold ). My garage gets upwards of 120 degress in the summer. I use mechanics paper towels and throw them away after each job and make sure all cloth towels are hung up and not collected together in some container. When it comes to fire, one must be very careful.

Good topic Charles.

All oily rags should be disposed of carefully, but there is a distinction between oils

For spontaneous combustion to occur, these things must be present:
1. A drying oil (vegetable or animal in origin-tung, boiled linseed, cod, soybean)
2. porous medium that allows free access of oxygen and doesn't melt when heated
3. adequate oxygen (a lid does help slow the reaction by limiting available oxygen)
4. time

A drying oil turns hard due to the fact that it polymerizes when it oxidizes. It won't self-heat in the can, but when you spread it out thin....
Hydrocarbon oils won't self-heat like this. If they do, it it because there is moisture involved. Moisture causes organics to rot and possibly self-heat. This takes much longer than self-heating cause by drying oils.

Common cooking oils usually won't self-heat, unless they have been used to cook and contain batter crumbs or cornmeal.

If you use a rag to wipe down something hot and throw it in the storage can, it increases the chances that spontaneous combustion will occur.

I apologize in advance for the schoolroom lecture, but I could not let the statement that there is no difference in oils pass any more than someone else could ignore a statement that you can kill an elephant with a .22 LR.....

[Idiot]

All oily rags should be disposed of carefully, but there is a distinction between oils.

I apologize in advance for the schoolroom lecture, but I could not let the statement that there is no difference in oils pass any more than someone else could ignore a statement that you can kill an elephant with a .22 LR.....

In the context of what we are discussing - that is possibility of oily rags spontaneously combusting and causing a fire - there is no distinction between oils - if handled improperly they can all cause a fire.

You say the very same thing - "all oily rags should be disposed of carefully." That is my point as well, only you say it better.

And as far as killing an elephant with a 22LR goes, I'd be real careful about making a general bet against it.

[Ysabel Kid]

Thank you for the reminder! Scary, scary thought!!!

[firefuzz]

All oily rags should be disposed of carefully, but there is a distinction between oils

For spontaneous combustion to occur, these things must be present:
1. A drying oil (vegetable or animal in origin-tung, boiled linseed, cod, soybean)
2. porous medium that allows free access of oxygen and doesn't melt when heated
3. adequate oxygen (a lid does help slow the reaction by limiting available oxygen)
4. time

A drying oil turns hard due to the fact that it polymerizes when it oxidizes. It won't self-heat in the can, but when you spread it out thin....
Hydrocarbon oils won't self-heat like this. If they do, it it because there is moisture involved. Moisture causes organics to rot and possibly self-heat. This takes much longer than self-heating cause by drying oils.

Excellent post, especially the oil distinction description. I served 28 years as a firefighter, the last 6 as an origin and cause investigator in the Fire Marshal's office. We usually had 3-5 fires a year caused by improperly disposed of oily rags, usually in homes and home shops of "tinkerer's" like us that have had little or no formal training in the use of finishes and thinners for their crafts.( and didn't read or head the warning on the containers ) Furniture waxes and polishes containing these products can also cause these same results. Allowing these items to be discarded in a pile or stack causes an insulation effect that allows the heat to build to ignition temps. Many of these substances will produce their own oxygen as they go thru the normal chemical change we call rotting. That and the heat the same change produces is what causes spontanious combustion.

Depending on the conditions, ignition can take place minutes or hours after the rags are disposed of, which is the real danger in one of these fires as they can act like a "slow match" and ignite sometimes hours after you've left the area.

An air-tight METAL container of moderate volume will usually prevent or contain a fire started by these items. I also encourage everyone to have a smoke detector in your shop area. All of us, I hope, have them in the living quarters of our homes...but do you have one in the garage/shop?

BTW, want to know what group of people have the largest percentage of accidental fires caused by things like this and the improper use of gasoline...? Firefighters, because they think they know better and can beat the odds. I've seen more than a few of these and as long as the fire isn't too serious you can just imagine the razzing they get at work after the fact.

Rob

[vancelw]

BTW, want to know what group of people have the largest percentage of accidental fires caused by things like this and the improper use of gasoline...? Firefighters, because they think they know better and can beat the odds. I've seen more than a few of these and as long as the fire isn't too serious you can just imagine the razzing they get at work after the fact.

Rob

We hired a guy about 25 years ago who had had a fire just months before he got hired. He was a volunteer at the time and his doghouse caught fire because he had a bare light bulb in it for heat with improper clearance.

.....He's the Fire Marshal now.

I'm glad you reminded me. I'll have to remind him later.

[firefuzz]

BTW, want to know what group of people have the largest percentage of accidental fires caused by things like this and the improper use of gasoline...? Firefighters, because they think they know better and can beat the odds. I've seen more than a few of these and as long as the fire isn't too serious you can just imagine the razzing they get at work after the fact.

Rob

We hired a guy about 25 years ago who had had a fire just months before he got hired. He was a volunteer at the time and his doghouse caught fire because he had a bare light bulb in it for heat with improper clearance.

.....He's the Fire Marshal now.

I'm glad you reminded me. I'll have to remind him later.

Wish I could be there.

Rob

[lthardman]

I actually teach a class on behalf of the Michigan Firefighters Training Council that covers this topic. The term spontaneous combustion is not used in scientific circles quite as much as "self heating" these days.

There are three conditions that must exist for this situation to occur:

1) The insulation properties of the material immediately surrounding the fuel (oil soaked rags) must be such that the heat cannot dissipate as fast as it is generated. (When natural oils like linseed or tung decompose, they generate heat. This is a form of oxidation. Oxidation, even the process of corrosion, gives off heat.) So if heat builds faster than it dissipates, then the temperature keeps rising until it hits the autoignition temperature.

2) The rate of heat production must be great enough to raise the termperature of the material to its ignition temperature

3) The available air supply (ventilation) in and around the material being heated must be adequate to support combustion.

So, anything that iterrupts one of the three conditions above will avoid the problem. Many of the suggestions mentione by others will work. If the area is VERY well ventilated, heat from the decomposing linseed or tung oil is dissipated before it can reach its autoignition temperature. If the heat production of the linseed or tung oil soaked rags is retarded due to being soaked in water, it will not reach its autoignition temperature. And, if you enclose the linseed or tung oil soaked rags in an air tight container, perferably metal, there is insufficient oxgen to support combustion.

Not only are oil soaked rags a concern. Other materials are also a concern when it comes to self heating. These include hay and manure. Those in agriculture know that if hay is baled or put up in large rolls when wet the increased level of decomposition can lead to a fire. Also charcoal can be a concern.

A true story: After we responded to and extinguished a structure fire, a young man at the residence told us he thought his tennis shoes had experienced spontaneous combustion and started the fire. We kind of doubted this. After our investigation, we found that the young man had actually been smoking in his closet. When he heard his parents return home, he had stashed all of his smoking materials in a shoe box. Apparently some had not been totally extinguished.

[Nath]

I have experienced linseed oil getting very hot on a cotton rag.
All mine go in the stove now where they can pleas them selves.
mineral oil rags are just as bad IMO. If a spark lands on them they can go up as and when.

Rust dust from steel is real good on cotton clothing and will smoulder nice n' quiet for a long time, my nose soon detects the smell nowa' days!

Nath.

[Idiot]

Charles, thanks for the topic. The audience here is full of folks where this topic applies. I, for one, cannot go a day without having my hands in some sort of oil or cleaner or some other volatile liquid.

Responding posters, thanks for posting. This topic went from general to specific to very informative (thanks vanclew for upping the ante). This thread will hit my favorites list.

[vancelw]

I, for one, cannot go a day without having my hands in some sort of oil or cleaner or some other volatile liquid.

Uh Oh. Now you've done it! We have to talk about cancer now

I'm out on that one. Not my bailiwick.

!!! MEDIC!!!

[firefuzz]

Apparently some had not been totally extinguished.

I can't even begin to count the fires I've fought/investigated that were started by similiar circumstances.

I used to teach part-time for Fire Service Training at OSU. A lot of my lectures on this type of topic used to start, "Now don't you knotheads go out and try this, just take my word for it...it will catch fire/explode." They wouldn't have taken that from anyone but another firefighter. Every student I ever had I gave my personal phone number, usually within a month or two after a class I'd get a phone call, "Hey Cap, remember telling us NOT to do.......we'll you were right, it caught fire/exploded."

Firefighters are just like little kids sometimes, ya gotta show 'em it's hot before they'll believe you. God knows I love 'em all.

Rob