# Hay Fire Safety Reminder



## downtownjr (Apr 8, 2008)

Studies have shown hay fires often occur within 6 weeks of baling high moisture hay. 
Some of us have hay in that time-frame that may have been baled in excess of 20 percent moisture. To be safe small rectangular bales should have moisture content less than 20 percent and large rectangular or round bales should have moisture content below 18 percent, according to various extension newsletters.

It is important to monitor bales stored that are wetter than normal to ensure they are not to hot. If high moisture hay is in your barn or field stack, one should check it daily for that 6 period. Also, give the stored hay the "sniff test". Hay bales produce a particular odor prior to spontaneous combustion. It is described as a "composting odor" and is an important warning signal. If this or a sweet caramel odor is present, remove bales to get to the center of the stack and probe bales to check temperatures.

When using a thermometer, measure the wettest hay first. Probe square bales from the side and round bales from the end. The probe should be inserted near the center of the bale. In round bales, if the core is loosely formed, probe six to 12 inches away from the center where the hay will be more tightly packed.

Some temperature guidelines to remember are as follows...It is not unusual for the temperature within a bale of hay to reach 100 degrees Fahrenheit and they may go as high as 130 degrees Fahrenheit before starting to decline. If the temperature peaks below 130 degrees, there is a minimal danger of fire. If you separate the bales and set them up with free air circulation around a bale, both heat and moisture can dissipate. A single bale rarely heats enough to catch on fire, but when they are placed close together or stacked with other bales that are also heating, it is much more difficult for the heat to leave the bales.

If the bales are wetter than they should be, the temperatures can easily rise above 130 degrees. At 140 to 150 degrees more microbial growth and chemical reactions within the hay cause it to generate heat at an increasingly rapid rate.

If hay temperatures reach 150 degrees, bales need to be moved to allow for better air circulation and the temperature should be checked frequently. At 180 degrees fire is imminent, and at 200 degrees it is likely to be present. In any case, when hay temperatures are 170 degrees or greater, you should immediately call the fire department. It is best to wait for them to arrive before removing the hay from the stack in case of a flame up. In addition, with these temperatures it is likely some hay has burned out middles and could collapse, injuring you. It is always better to be safe and await the fire department.

Also, one idea mentioned in one of the articles that may be worth keeping in mind is that commercial hay probes are good but are too short to probe the center of hay stacks. Use a 10-foot iron pipe with eight 0.375-inch holes drilled approximately 3-inches from one end, hammer that end together to form a sharp end. This will make a simple probe that can reach deep into the center of your stack. Lower a thermometer to the end of the probe with a piece of small wire. After 15 minutes retrieve the thermometer. If the temperature is nearly 150 degrees F the temperature will most likely continue to climb. Remove hay to provide circulation and cooling.

In summary, try to keep the moisture content less than 20 percent and large rectangular or round bales should have moisture content below 18 percent. An investment in preservatives offered by Hay Guard and Silo-King for wet times as experienced in some area of the country could be worth the money. But they are only good to certain point. So please watch your hay if this year's rain caught you...I have been there. I almost wondered if I was supposed to wash my hay and mother nature was trying to be helpful...Anyway be safe out there.

Sources: Temperature Checking Hay Can Keep Fires at Bay
Only you can prevent hay fires DairyHerd.com - Forage Resource Center


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## mlappin (Jun 25, 2009)

While we are on the subject, here's the temperature chart from my Purdue Extension Field Forage Guide:

125F: No action needed

150F: Entering the danger zone. Temperature should be checked twice daily. If possible, stacked hay should be disassembled to allow more air to move around heated bales for cooling.

160F: Reaching the danger zone. Temperature should be checked every couple hours. If possible, stacked hay should be disassembled to allow more air to move around heated bales for cooling.

175F: Hot spots or fire pockets are likely. If possible stop all air movement around hay. Alert fire service of possible hay fire incident.

190F: Remove hot hay. This should be done with fire service assistance. The fire service should be prepared for hay to burst into flames as it contacts fresh air.

200F or higher: Remove hot hay. A fire is certain to develop. This should be done with fire service assistance. The fire service should be prepared for hay to burst into flames as it contacts fresh air.

Source: Extinguishing Fires in Silos and Hay Mows (NRAES-18)


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## swmnhay (Jun 13, 2008)

Have a couple dips in grass field where water was sitting.Made 1 bale out of it to get it off field.3240 lbs,monitor just said WET.I set in corner of field out of the way.I wish I had a thermometor when I checked it a week later, it was HOT,thought maybe was going to get a blister on my finger.


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## CantonHayGuy (Sep 25, 2008)

This is good info to review....... or view for the first time.


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## vifarmgirl (Jul 22, 2010)

This is good to know...this is my first year of baling our own hay and some of the bales seem a bit moist...I am going out to buy a hay/forage moisture meter today and will be testing each and every one of them. They were just baled yesterday so should I pull any wet ones apart for drying and re-baling or just scrap them?


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## downtownjr (Apr 8, 2008)

Welcome to HayTalk. On your question, _not knowing what the moisture or temperature you are looking at is_, getting a good meter to check the temperature and moisture of the bale would be a good idea. The bales will go through a sweat and get up to around 130 degrees. If they are stored in a place that the air moves through they will dry a bit, usually a storage barn that has good circulation and a place for the wet moist air to move up and away from the hay to help it dry. If they are enclosed in a haymow and packed tight with little air movement that could be a problem. I store them on edge and leave some spacing if it is a little moist. Some people salt it, but I never have, so maybe some of the folks can tell you how they go about that. If you are in area that usually is hard to bale hay without fighting the wet weather, a preservative like hay guard or silo king may be worth the investment. Another way to check the moisture is to use a microwave checking system before you bale. Here a link to the process. http://www.abe.psu.edu/extension/factsheets/i/I106.pdf It is by far the most accurate, but always remember you can get pockets of moist hay and pockets of dry as well, so sample a few areas. If you have a friend that has baled for some time, see if they can stop in and look at it and provide some advice. A good mentor as you start making hay is always a good thing...it is an art and science.


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## vifarmgirl (Jul 22, 2010)

Thank you...I am on my way to town in a couple of minutes to buy a good hay moisture meter...I will post the moisture content this evening when I go back on the computer. I live in Northern BC where it is very dry most times and the hay is going into a open pole barn with lots of air movement. The hay is not stacked yet but is in 4 bale stooks on the field with aprox 200 bales stacked on edge beside the pole barn as I wasn't sure about the moisture content and didn't want to get it into the barn and have to take it all out.


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## vifarmgirl (Jul 22, 2010)

I ended up testing the bales and some of them came up with a moisture content of 35% We ended up breaking open about 200 bales and spreading them around for a couple of days...raking them twice and re-baling them...the hay looks and smells wonderful! Thank you sooo much for the advice as we most certainly would have had a fire in our barn...at the very least the hay would have been horribly moldy when we needed it most!


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