Yes. Ironically wet or moist hay, in particular, is more likely to catch fire on its own (spontaneous combustion). This is due to plant reactions and bacterial growth that combine to raise temperatures inside the bales.
What causes hay to catch on fire?
“Excessive moisture is the most common cause of hay fires,” Schroeder says.” Odd as it might seem, wet hay is more likely to lead to a spontaneous-combustion fire than dry hay.” High-moisture haystacks and bales can catch on fire because they have chemical reactions that build heat.
How often do Hay fires occur?
Hay fires usually occur within six weeks of baling, but they may occur in hay several years old. Fire can occur in loose hay, small bales, large bales or in stacks. The fires can occur in hay stored inside as well as in hay stored outside.
Why is Hay flammable?
When hay’s internal temperature rises above 130 degrees Fahrenheit (55 degrees Celsius), a chemical reaction begins to produce flammable gas that can ignite if the temperature goes high enough. Fire is possible in hay that’s loose, in small or large bales or stacks, and stored inside or outside.
Can a bale of hay spontaneously combust?
If bacteria accumulate to a high enough degree, then a bale of hay absolutely could spontaneously combust. The hay can just be sitting there, untouched since when you initially stored it in your shed, yet it will still catch fire. When you cut your crop, its important to monitor the stalk for moisture before it is baled.
How long does it take for hay to catch fire?
When the internal temperature of hay rises above 130 degrees Fahrenheit (55 degrees C) it provokes a chemical reaction producing flammable gases that can ignite. Most hay fires occur within 6-weeks of baling.
Is hay very flammable?
Flames will likely develop when heating hay comes in contact with the air. 212°F (100°C) Critical! Temperature rise is rapid above this point. Hay will almost certainly ignite.
How do you stop hay from catching on fire?
The best way to reduce the risk of a hay fire is to bale hay at a moisture content of 20% or less because at this moisture level, microbial activity decreases.
Can moldy hay spontaneously combust?
As spring progresses, higher ambient temperatures together with air infiltration favor the growth of bacteria and molds that further build-up heat. If air continues to penetrate the mass, oxidation by these microorganisms may continue until spontaneous combustion occurs.
Can old hay self combust?
When hay's internal temperature rises above 130 degrees Fahrenheit (55 degrees Celsius), a chemical reaction begins to produce flammable gas that can ignite if the temperature goes high enough. Fire is possible in hay that's loose, in small or large bales or stacks, and stored inside or outside.
Can hay bales self combust?
“Strange as it may seem at first, wet hay is more likely to spontaneously catch fire than dry hay,” said Josh Bushong, Oklahoma State University Extension area agronomy specialist for western Oklahoma. “Excessive moisture is actually the most common cause of fire in hay bales and stacks.”
How hot does hay get?
Most hay goes through one or more heating cycles (a “sweat”) immediately after baling. It is not unusual for internal bale temperature to exceed 100° F, and it may go as high as 130° F if enough moisture and oxygen is present. The graph shown here illustrates a typical heating cycle for moist and dry hay.
How long will a hay bale burn?
Hay fires usually occur within six weeks of baling, but they may occur in hay several years old. Fire can occur in loose hay, small bales, large bales or in stacks....Table 2.Table 2. Temperature InterpretationsBelow 130°FNo problem130 to 140°FNo problem yet, temperature may go up or down. Recheck in a few hours.3 more rows
How flammable is straw?
It may seem like a house insulated with straw poses a significant fire hazard. Yes, loose straw is indeed highly flammable. Yet, EcoCocon straw wall panels provide excellent fire resistance that is comparable to or even higher than other construction materials.
Can hay bales explode?
Moisture. If the hay is baled before it is totally dry, it can blow up. Literally.
Why does hay heat up?
Plant cell respiration burns plant sugars to produce energy. This is a normal process as the hay plant tissue dries down and is often referred to as “sweating” or “heating” and occurs until the plant material is less than 15% moisture.
What temperature does hay start to mold?
“Hay bale temperatures of 120°F to 130°F will likely result in mold growth and will make the protein in the hay less available to animals,” Hartschuh says. While these temperatures will not cause fires, continued mold growth can raise temperatures to dangerous levels.
Does hay generate heat?
Plant reactions and bacterial growth combine to raise temperatures in even the driest hay bales, although most never catch fire on their own. However, when hay is packed tightly, and enough moisture gets in, the conditions may be right for spontaneous hay combustion. How does this work?
Is straw flammable?
It may seem like a house insulated with straw poses a significant fire hazard. Yes, loose straw is indeed highly flammable.
How hot can hay get?
Most hay goes through one or more heating cycles (a “sweat”) immediately after baling. It is not unusual for internal bale temperature to exceed 100° F, and it may go as high as 130° F if enough moisture and oxygen is present.
Is burning hay toxic?
Smoldering and burning hay can be the source of toxic gases. Carbon monoxide can be concentrated within the smoldering fire and surrounding area. Chemically preserved hay crops may produce toxic gas vapors. Deadly gases add to the fire risk.
Why is hay burning so bad?
This year has been particularly bad for hay heating due to the hot humid weather . If the hay crop is put into the mow above 20-25% moisture content, spontaneous combustion may occur. A hay crop that is placed too wet into a mow will heat rapidly.
What gas is used to fight hay fires?
Hay treated with preservatives containing ethoxyquin and BHT (butylated hydroxytoluene) will produce hydrogen cyanide gas at around 240°F (115°C). This gas is very deadly.
How to check if hay is heating?
What do you do if you suspect that your hay is heating? First of all, make yourself a simple probe that can be inserted into the hay mass to check the temperature. A probe can be made from a 10 foot piece of electrical tubing. Rivet a hardwood pointed dowel to one end and drill 8 - 3/16 inch diameter holes in the tube just above the dowel. Drive the probe into the hay mass and lower a candy thermometer on a long string into the probe. The thermometer should be left for 10 minutes to ensure an accurate reading.
What happens when hay is wet?
A hay crop that is placed too wet into a mow will heat rapidly. If the mow is so large that heat loss is restricted, the internal temperature will rise. As the temperature rises above 130°F (55°C), a chemical reaction occurs and may sustain itself. This reaction does not require oxygen, but the flammable gases produced are at a temperature above their ignition point. These gases will ignite when they come in contact with the air.
What to do if hay burns under your waist?
Pockets may have already burned out under the hay surface. Always tie a rope around your waist and have a second person on the other end in a safe location to pull you out should the surface of the hay collapse into a fire pocket.
Does salt cause spontaneous combustion?
However, tests have shown that salt has no effect on controlling spontaneous combustion. Dry ice, liquid nitrogen or carbon dioxide gas pumped into the hay will prevent combustion by eliminating the oxygen from the hay mass. Spontaneous combustion is not an accident.
Does hay need oxygen?
This reaction does not require oxygen, but the flammable gases produced are at a temperature above their ignition point. These gases will ignite when they come in contact with the air. Check your hay regularly. If you detect a slight caramel odour or a distinct musty smell, chances are your hay is heating.
What causes hay fires?
Some of these causes are lightning striking nearby trees or fences, arson, contact with electric fences and sparks from cigarettes, welding or nearby fires. Measuring.
How long does it take for hay to start catching fire?
Hay fires usually occur within six weeks of baling, but they may occur in hay several years old. Fire can occur in loose hay, small bales, large bales or in stacks. The fires can occur in hay stored inside as well as in hay stored outside. Regardless of when or where the fires occur, the most common cause is excessive moisture.
What temperature does hay need to be to be cured?
After baling, however, a small supply of air and a favorable moisture level cause the microorganisms to begin to feed and multiply, generating heat in the process. This heating continues up to a temperature of 130 to 140°F, at which the heat tends to kill the microorganisms.
How much humidity does hay need to dry?
Weather conditions greatly influence the rate at which the crops dry. Ideal hay curing weather has less than 50 percent relative humidity and some wind. Be aware that the moisture content of the hay will increase overnight when the air is humid, especially if there is dew or fog. Monitor weather forecasts carefully to help schedule haymaking operations.
What is the thermophilic bacteria in hay?
The thermophilic bacteria and the heat they generate convert the hay to a form similar to a carbon sponge with microscopic pores. In this form and at the high temperatures present in heated hay, the material combines readily with oxygen.
Can cows eat brown hay?
No fire results in a case like the one described above, but there may be considerable heat damage to the hay. In some cases cows may actually prefer the taste of the brown, heat-damaged hay but the feed has decreased considerably in nutritional value .
Is fresh cut forage dead?
Freshly cut forage materials are not dead. Some respiration continues and a very small amount of heat is produced. This heat generated by respiration is probably of little consequence except that it may help provide proper conditions for growth of bacteria.
