Here is the science behind wet hay heating up then spontaneously combustion!
Fire destroys greenhouse
By Vanessa Overholser - Staff Writer
A local greenhouse caught fire after a pile of hay and straw spontaneously burst into flames Monday afternoon, officials said.
The fire broke out in one of the greenhouses located at the More Than Mulch farm owned by Keith Kappes and his sons. Fire departments from Route 377 and Morehead rushed to 250 Gordon Lane near Weaver Hole Estates at 3:30 p.m. to put out the blaze.
“Two of our part-time employees were watering plants when one employee said he thought he smelled something burning,” Kappes said. “By the time they got there, the flames were shooting through the roof.”
The greenhouse contained a large pile of bales of hay and straw and some plants. Kappes said the hay and straw were the cause of the fire.
“It appears that it (fire) was caused by spontaneous combustion with the combination of hay and straw stored in a small space,” Kappes said. “Plus moisture was present from where it had rained.”
Jason Peace was one of the employees who discovered the fire. He recounted his events at the onset of the fire and what went through his mind as he reacted to the incident.
“We were in the second building when we smelled the smoke and we got out,” Peace said. “The first thing I thought of was to get out of the building and call 9-1-1. We started moving equipment.”
Tyler Fryman described the moments before witnessing the fire.
“I turned around and looked outside at the greenhouse next to us,” Fryman said. “It didn’t register at first when I saw it. I turned around and he (Jason) said ‘man that thing is on fire.’ We ran out and started moving equipment.
“The straw and hay pretty much exploded,” Fryman said. “I tried to put it out with a water hose but Jason said that won’t work. He was right. It didn’t work.”
Nobody was harmed during the fire, Kappes said.
“We are thankful nobody got hurt and for the quick response of the fire departments,” he said.
Ironically, Kappes and his staff had talked about moving the straw and hay to another location before the fire. The Kappeses had one problem. Their equipment was taken out-of-town to clean up areas in western Kentucky that were devastated by the recent winter storm. Then the straw caught fire on Monday.
Kappes was not worried about the extent of the loss caused by the fire.
“We are fully insured,” Kappes said. “The fire destroyed the greenhouse the hay and straw were in and it melted 40 percent of the plastic (exterior of building) on the greenhouse next to it. We had some plants lost. Most of the plants we have left can be salvaged.”
Director of the Morehead-Rowan County EMS and member of the Route 377 Fire Department Danny Blevins said it took a lot of water to put out the flames.
“It took four tankers (two from Morehead and two from Route 377) and 9,000 gallons of water to suppress the fire,” Blevins said. “Fire officials called for a backhoe to be brought on the scene to spread out the hay and straw so they could extinguish the fire.”
It took more than three hours for firefighters to battle the blaze and clear the scene. The fire remains under investigation by the Route 377 Fire Department
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.