Wet Hay Fire Hazzard

[Arklatex]

I had always heard that you shouldn't bale wet hay because they can catch on fire. I wasn't sure weather to believe it or not, sounded kinda like an old wives tale. 2 days ago I saw proof for myself. Some neighbors down the road cut and baled their hay. They are new to it and this is the first year they've done it. They raked and baled a 30 acre plot across from their house early in the morning after some light rain overnight. The bales caught fire by evening and they lost every single one in that field. Lucky for them it didn't start a field fire or damage the house or equipment. Their other 50 acre field was fine, none of the bales caught fire. This is just a reminder to anybody that might be bailing their own hay for livestock or market.

Here is the science behind it as told by a Firefighter:

Beware of hay fires...

Wet hay favors the growth of organisms which generate heat and can increase hay temperatures up to 150 degrees F. Once hay heats beyond this point, chemical reactions take over and can increase temperatures to the point of spontaneous combustion. With "wet" hay packed tightly in bales and stacked together in large quantities, fires are very possible. Whether hay which is in this situation actually starts to burn or not depends mostly on the size of the stack and the material surrounding it.

If hay is stacked loose and sufficient cooling occurs at the same rate as the heat is generated, the hay may simply caramelize and turn brown or simply mold. However, if there is enough hay on the outside part of the hot spots to prevent the escape of heat, and the carbon, nitrogen, oxygen and moisture levels are right, a fire will eventually occur due to spontaneous combustion.

If you suspect that your hay may be heating up, the temperature can be measured and monitored by using the following process:

Drive a pointed 2" pipe into a hay bale and lower a thermometer on a string down into the pipe. Wait 10-15 minutes for the temperature to stabilize, then pull it out and read the temperature. Repeat this in several bales. If a thermometer is not readily available, drive a solid metal rod or pipe into the center of the bale and after 15-20 minutes withdraw the rod. If it is too hot to hold in your hand, the situation is critical. The temperature should be determined and appropriate action taken.

Actions to take...
If temperatures are below 140 degrees F there is not any danger, unless it is early in the process.

When the temperature is between 140-160 degrees F, check bales daily

If temperatures rise above 160 degrees F, check every 2-3 hours and prepare to move the hay from the building and spread out so that air can get around the bales.

If the temperature reaches 180 degrees F, notify the fire department, insurance company (if the building is insured) and remove all equipment and/on animals from the area. With fire equipment on hand (not just an extinguisher), remove bales to the outside and do not stack. Place in rows for easy access. During removal, be alert for burned out cavities. Also, hay under these conditions may flame up as fresh air strikes it or smolder in a pile for weeks.

If bales ignite, soak with water and force some water in the center of the bales.

If the bales do not ignite, try to save the hay by allowing the bales to simply cool down.

Continue to monitor the internal temperature of the bales. The hay may be put back in the building after the temperatures drop below 100 degrees F.

[MrsInor]

Interesting. Always nice to learn something new that I may have need for knowing in the future. My uncles used to spread rock salt between each layer of bales. Maybe to help keep the bales drier?

[Coppertop]

There is a newer way to prevent this. We have been using it in the North for a few years now. As soon as the hay is cut, it is baled (as long as it isn't raining on the hay) and they almost immediately wrap the bale in plastic. This creates a complete air barrier and doesn't allow anything to grow inside the bales. Anaerobic (no air) conditions are created. Then the plastic is cut off after the weather gets below freezing for a few days although you could cut it off as you feed it. There are rows of white plastic covered bales all over. The manpower used for this process is pretty high, but the man hours is pretty short. They use about 6 guys on a crew, but they flat get after it.

The wetter and fresher cut the hay- the more nutrients stay with the hay and makes the quality much better. When hay dries out between cutting and baling, the leaves/nutrients fall off when the baler picks the hay up.

Thanks

[Coppertop]

Interesting. Always nice to learn something new that I may have need for knowing in the future. My uncles used to spread rock salt between each layer of bales. Maybe to help keep the bales drier?

My guess would be to kill/deter bugs.

Thanks

[Deebo]

I learned something.
I have seen cotton bales catch fire, in the cotton mill. They just drive it outside and dump it by the other burned one's. It smolders more than burns.
I knew a guy that into a dispute bwith a farmer, went around depositing lit cigarettes in the farmers cotton bales.

[Sparkyprep]

I'm not sure about hay, but cotton mills are considered "Explosive Environments" by the NFPA. Cotton fibers, floating in the air, can literally explode the air when lit, due to extremely rapid combustion. There are special requirements for any electrical systems, just like areas with gasoline vapors.

(Just a bit of useless electrical code trivia)

[Arklatex]

There is a newer way to prevent this. We have been using it in the North for a few years now. As soon as the hay is cut, it is baled (as long as it isn't raining on the hay) and they almost immediately wrap the bale in plastic. This creates a complete air barrier and doesn't allow anything to grow inside the bales. Anaerobic (no air) conditions are created. Then the plastic is cut off after the weather gets below freezing for a few days although you could cut it off as you feed it. There are rows of white plastic covered bales all over. The manpower used for this process is pretty high, but the man hours is pretty short. They use about 6 guys on a crew, but they flat get after it.

The wetter and fresher cut the hay- the more nutrients stay with the hay and makes the quality much better. When hay dries out between cutting and baling, the leaves/nutrients fall off when the baler picks the hay up.

Thanks
I've seen them do this up in Oklahoma but never knew the reason for it. Thanks for the explanation. I always thought that they looked like fields of giant marshmallows!

[Deebo]

Yes, the cotton gins are flammable.
I used to deliver motors, then help mount them, then make the connections and check for rotation.
This was twenty years ago, and all they cared about was getting the "line running". Again.

[Arklatex]

Unbelievable! A year and 1 day later I'm digging up this old post. The exact same neighbors have done it again! I been smelling smoke for the last few hours and went to investigate. Smoldering bales. Dumbasses!!!!

[Baglady]

Unbelievable! A year and 1 day later I'm digging up this old post. The exact same neighbors have done it again! I been smelling smoke for the last few hours and went to investigate. Smoldering bales. Dumbasses!!!!

Some people have to learn the hard way? A guy I know lost his truck, trailer, and hay barn to spontanious combustion. And he did know better.

[RubberDuck]

seen a few barn fires from hay hmmmm hey hawg stack a few in your garage

[hawgrider]

seen a few barn fires from hay hmmmm hey hawg stack a few in your garageYa know.... I need some hay for the chickens nesting boxes.

Who has some green hay for sale?

[BucketBack]

Sawdust will burn for years.
Look behind most sawmills and you'll see a sawdust fire.
It's fine until you add water, like rain from the sky.