Lethal carbon monoxide poisoning in wood pellet storerooms

[Sophie]

FYI - I heard about this at work:- I don't know if pellets in Europe are made differently than in the US? This is very serous. I hope that everyone has working CO detectors.

.http://www.ncbi.nlm.nih.gov/pubmed/22879445.

 

[Sophie]

More information on this - the storehouses they are talking about are actually residential storage containers. There is more info at http://www.safteng.net/index.php?option=com_content&view=article&id=2239&Itemid=4:

"Wood pellets for boilers are normally stored in a large sealed hopper/tank or a storage room that has a screw feeder (auger) connected to the boiler. Alternatively, the hopper/tank can be mounted over the boiler for gravity feeding. Due to the enclosed nature of these hoppers/tanks/rooms, the atmosphere inside can become oxygen depleted and a toxic atmosphere containing carbon monoxide can accumulate. The chemical reactions responsible for carbon monoxide production from wood pellets are assumed to be an auto-oxidation process, especially oxidation of the fatty acids to be found in wood4."

 

[SmokeyTheBear]

Well I guess that goes to show that one should not enter sealed containers connected to a burning device by an auger. Do a search on here on gummy stove. Same thing writ small.

Or roll in large piles of freshly made pellets inside an unventilated building.

 

[rickwai]

The only way that I can see this would affect us is if we were to get inside of our hopper on top of our stove. I dont know about anybody else but I usually dont climb into my hopper and hang out...

 

[stoveguy2esw]

strikes me there have been accidental deaths from people in grain silo's in the past. probably due to the same conditions

 

[smwilliamson]

making your own bulk feed storage bin is a bad idea....unless you are an engineer.

 

[SmokeyTheBear]

Nothing like a big one if you are going to do it however.

http://american-colossus.blogspot.com/2009/05/grand-trunk.html

 

[moburns]

Im confused. Do pellet put out carbon monoxide with out being burned? I have just about two tons scattered all over my home. Is the CO not an issue because of the amount or because of the place I am storing? I do have a CO detector.

 

[SmokeyTheBear]

Maria,

Look at where and how those fatalities occurred.

Do you enter what appears to a normally closed feed hopper connected to a heating device for 60 homes?

Are you down inside a full cargo hold on a ship carrying warm just made pellets?

What is your CO detector reading?

 

[moburns]

Am I misreading something. It looked like the casulties happend by people entering pellet storage areas. I didn't know the people were entering hoppers, thats crazy.

If I tried to climb into my 50lb pellet stove hopper I think I would destroy the stove and maybe the pre-fab chimney housing the pellet liner and I certainly would not be able to close the lid.
My house could possibly fit inside of a cargo liner that ships pellets but at this point it is tied to some cynder blocks in the mobile home park.

I am not sur ewhat the CO detector reading is but it is not alarming me to any issues.

 

[SmokeyTheBear]

In Europe they have some large systems that provide heat for many buildings and they have automated from storage to burner delivery (large auger systems).

Since it takes a specific concentration for a specific exposure time to cause a problem one should never enter a building that directly feeds fuel (any fuel) via an open pathway (auger) to a large combustion device.

The mere opening of the door can result in combustion byproducts entering the area. It is also an area with little remaining space at times thus the concentration of anything in the air there can be a lot higher than it is outside that area.

The same thing is true of a loaded ship's hold.

I posted a link in a thread yesterday IIRC showing the concentration levels and effects of CO, it even has the "normal" air levels of CO in it. Here is that post: https://www.hearth.com/talk/threads/co-exhaust-gas-compositon.101454/#post-1304097

 

[moey]

Seems like they could avoid this by just letting them sit in a ventilated area for a couple days. I'd suspect these pellets are being stored still warm.

 

[Sophie]

The second article said:

"In November 2010 a 38-year-old male householder in Ireland died after entering the 7 tonne wood pellet storage room for his boiler. His wife and another
man were treated in hospital after trying to pull him to safety."

I don't have a bulk storage container but I have read on this site that people have built them in their cellar - I don't know how large they are, and I am not sure why the man who died entered his storage room, but I also don't understand why people people who use wood pellets wouldn't want to completely understand how/why wood pellets emit carbon monoxide.

Kind of reminds me of smokers were denial decades ago about the effects of cigarettes. I smoked for 26 years before I was able to give them up but I always realized that putting smoke into your lungs was probably not a very good idea.

 

[SmokeyTheBear]

Sophie,

If the pellet storage was hooked directly to his boiler then it is the same situation as the setup feeding a heating system for 60 houses.

I am not doubting that pellets off gas when they leave the dryer. In fact I don't doubt that cord wood off gases as it drys.

I also am a firm believer in having the proper operational detectors in the building which means both CO and Smoke.

I currently have over 10 ton in my garage along with a forced hot water boiler there is a smoke, fire , and CO detector in there interconnected to 4 other siblings.

I once had 18 ton in there no alarms sounded except for the reminder to replace the backup batteries.

 

[SmokeyTheBear]

Just a bit more information: http://www.hse.gov.uk/safetybulletins/co-wood-pellets.htm

 

[Sophie]

It appears that pellets bought in bulk are fresher and therefore expel more carbon monoxide than pellets that have been packaged, shipped to a retailer, held for a period of time and then sold by the ton. I don't know if you have a pellet storage container but it appears that a CO meter would not detect CO in the sealed bulk storage containers but would present a danger when opened - and apparently there is a reason for opening the containers since they are built with access doors. The storage containers are a new concept in the US and consumers should definitely be educated on the CO danger and provided with safety data sheets whether they buy in bulk or in bags.

 

[SmokeyTheBear]

It appears that pellets bought in bulk are fresher and therefore expel more carbon monoxide than pellets that have been packaged, shipped to a retailer, held for a period of time and then sold by the ton. I don't know if you have a pellet storage container but it appears that a CO meter would not detect CO in the sealed bulk storage containers but would present a danger when opened - and apparently there is a reason for opening the containers since they are built with access doors. The storage containers are a new concept in the US and consumers should definitely be educated on the CO danger and provided with safety data sheets whether they buy in bulk or in bags.

I do not have a bulk storage (in a confined space with practically no chance of air transfer the usual cause of death for these cases is severe lack of oxygen) silo or space nor am I connected to any auger system dumping pellets into a burner system.

Such systems start out oxygen depleted. So even a very small amount of anything else usually is in high concentration.

Since they haven't provided any actual test results in any of the information I've seen it is quite possible that this was a contributing and even possibly the real issue.

The US CDC has information on some 600+ cases of death in what are classified as confined spaces.

In 42% of the cases it is oxygen deprivation that is the problem, cases of this nature can involve just opening the access area, going inside, and expiring.

 

[Sophie]

OK - Let's not bury our heads in the sand and recognize that there is a very serious CO problem w/wood pellets and not dismiss this as caused by oxygen depletion in a confined space.

(broken link removed to http://www.pellet.org/images/2010-02-26_Review_of_Off-gassing_from_Wood_Pellets.pdf)

Empty confined spaces don't kill people - wood pellets stored in confined spaces kill people.

 

[SmokeyTheBear]

OK - Let's not bury our heads in the sand and recognize that there is a very serious CO problem w/wood pellets and not dismiss this as caused by oxygen depletion in a confined space.

(broken link removed to http://www.pellet.org/images/2010-02-26_Review_of_Off-gassing_from_Wood_Pellets.pdf)

Empty confined spaces don't kill people - wood pellets stored in confined spaces kill people.

Actually any thing that fills up a confined space can kill people, this includes other people.

 

[SmokeyTheBear]

From your PDF Sophie:

 

[SteveB]

Empty confined spaces don't kill people - wood pellets stored in confined spaces kill people.

You most certainly can die in an empty confined space. We get training every year at work. Can depend on what was in there before it was emptied and if its sealed it can have an oxygen depleted atmosphere. Just opening a hatchway to get in doesn't necessarily let enough oxygen into a depleted atmosphere unless its ventilated somehow. Sorry, not trying to bust your chops, training comes from OSHA. People die every year.

 

[Pellet-King]

rubbish!!

 

[Dgopetactical]

Carbon DIOXIDE is what is put off from composting wood and what is in farm silos. carbon monoxide is a gas that comes from incomplete combustion Of various fuels. Both deadly killers. If you have carbon monoxide in your pellet storage area it's not your pellets.

 

[hoverfly]

It would be a good idea to add venting in those storage boxes.

 

[TheMightyMoe]

Smokey is on target.

If you have a large "sealed" hopper, CO ((FROM THE DEVICE IT IS HOOKED TO)) will gradually fill the hopper up, and leak out into the room the hopper is in. If the room is sealed, CO being a heavy gas will fill the room top to bottom, making it a death trap. Those large pellet hoppers are NOT air tight.

The reason you don't have this kind of problem with a stove, is because the stove/hopper are all contained in one unit, and fresh air is constantly being moved in and out of that room.