Most individuals look for water to put out a fire, but hay and straw are the exceptions to this rule. When hay and straw become too wet, they can increase in temperature and erupt into flames. While this is more common with hay than straw, the risk exists for both. This is because moisture causes the bacteria in hay and straw to release heat. If the bacteria dies, the bales will cool. However, if the bacteria gains a foothold, temperatures can soar over 175 degrees Fahrenheit.
How to Store Wet Bales
Farmers should store their wet bales outdoors or in a large, open area. In addition, farmers should not stack wet bales as this prevents heat and moisture from leaving. It is important to note that hay often goes through a sweat period in the initial days after baling. Temperatures can increase up to 110 degrees Fahrenheit without causing concern.
Most Common Fire Risks
Several factors influence the combustibility of hay and straw. For example, hay is most like to catch on fire during the first six weeks after baling. Other factors include:
- Fields with wet spots
- Moisture levels exceeding 20%
- Bales containing more than 20% of hay preservative
How to Monitor Wet Bales
Farmers with at-risk bales of hay or straw need to keep a close watch to avoid fires. They should check the bales two times per day for the first six weeks after baling or until temperatures return to stable levels. To obtain a proper temperature reading, farmers should probe the center of the bale or at least eight feet down into oversized bales.
Determining Critical Temperatures
Below is a list of temperatures and the necessary actions farmers should take to avoid a fire.
- <125°–No immediate action
- 150°–This is approaching the fire hazard zone. Monitor twice per day. Farmers can take bales apart to promote airflow.
- 160°–This is the point of a fire hazard. Farmers should check bales every two hours and take bales apart. Farmers should recruit the fire department before unstacking additional bales.
- 175°–Bales are likely to have hot pockets at this temperature. Farmers should inform the fire department of a potential incident. Farmers can also create a tight seal on barn doors to remove oxygen.
- 190°–Farmers need the assistance of the fire department to remove overheated bales at these temperatures. Bales may burst into flame so farmers should wet down tractors.
- >200°–A fire is likely at this temperature. In addition to the precautions above, farmers should have fire hose lines ready to go.
While taking preventative measures is key to avoiding barn fires, they can still happen. Farmers need to invest in insurance to protect their assets in the event of a barn fire. As a leading provider of agribusiness insurance, Cline Wood can help farmers identify and manage fire risks as well as discuss their insurance needs. Contact us to learn more.
This document is not intended to be taken as advice regarding any individual situation and should not be relied upon as such. Marsh & McLennan Agency LLC shall have no obligation to update this publication and shall have no liability to you or any other party arising out of this publication or any matter contained herein. Any statements concerning actuarial, tax, accounting or legal matters are based solely on our experience as consultants and are not to be relied upon as actuarial, accounting, tax or legal advice, for which you should consult your own professional advisors. Any modeling analytics or projections are subject to inherent uncertainty and the analysis could be materially affective if any underlying assumptions, conditions, information or factors are inaccurate or incomplete or should change.agribusiness safety, agriculture risk management, farm safety, farming risk management