With silage carefully stored inside of a silo made of metal or concrete, farmers may not think to plan for the possibility of a fire in these storage units. Needless to say, fires (especially the slow, smouldering kind) can affect silos and require a unique approach when trying to extinguish.

There are three different kinds of silos:

• Conventional
• Oxygen-limiting
• Modified oxygen limiting (usually modified at the loader)

All silos pose a risk to people should they try to enter the unit. Oxygen-limiting silos pose an added risk of dense carbon monoxide and nitrogen oxide gases inside the silo which can asphyxiate fire fighters.

Silo Fire Risk Management for Farmers

Planning

The first bridge to cross after identifying a risk is to plan for it. If you have silos on your farm, add them to your risk management plan and consider:

1. How could a fire ignite?
   1. Nearby buildings or machinery could ignite and spreading fire may affect silos
   2. Working on machinery or using welding tools or other tools
   3. Spontaneous combustion from the silage becoming too hot as it cures
   4. Explosion from accumulated dust (e.g., grain, corn, safflower, sugar, wheat dusts)
2. What would I do if a fire starts in my silo?
   1. Write a step by step plan so you and farm workers know how to address a silo fire
   2. Consider some of the following steps and what order makes the most sense for your farm
      • Call the local fire department
      • Complete a site check of the entire area
      • Confirm what material is burning
      • Raise the unloader to prevent damage
      • Safely disconnect any electrical supply to the silo
      • Set up your own fire fighting apparatus
      • Move machinery and farm livestock out of the area

3. Hosting a fire drill
4. Documenting important details about the silos on your property and keep it handy for any fire fighters that attend the scene
   1. Dimensions
   2. Age
   3. Usual contents
   4. Type of silo
   5. Type of unloader

Prevention

Regularly monitor silos for temperature and humidity. For materials prone to spontaneous combustion (like silage) this is a critical best practice to prevent fires.

Look for other ways to prevent fires from starting such as:

• Equipment that may spark
• Designated smoking area
• Inspection of any electrical parts to prevent arcing (e.g., the unloader)
• Lightning protection system
• Dust control protocols

Responding

Fire fighting response is determined by the type of silo and what is stored inside of it. A good starting point for response is the silo manufacturer, sometimes they will provide guidelines for fighting fires. If provided, ensure you read and understand the recommendations for your silo.

Due to the possibility of asphyxiation from gases within the silo, all people responding to the fire should take precautions using air quality measurement tools nearby the silo, when in doubt of air quality wear full protective gear.

Due to the possibility of grain entrapment, people should never enter a silo while responding to a fire.

Conventional Silo Fire Response

Common fire response strategies include:

• Spray water from above into the silo.
• • If the material absorbs water, it could affect the structural integrity of the silo
  • After the fire is under control, it is recommended to use water sparingly
• Inject carbon dioxide or nitrogen gas into the silo to extinguish
• Discharge the silo
• Ventilation from the top of the silo, if possible

Oxygen-limiting and Modified Oxygen-limiting Silo Fire Response

Oxygen-limiting silos are specifically designed to minimize oxygen. If you identify a fire in this type of silo, a very important best practice to prevent explosion is to avoid introducing more air into the silo e.g., opening a hatch.

Common fire response strategies include:

• Allow fire to self-extinguish by ensuring all hatches and door are closed
• Inject carbon dioxide or nitrogen gas into the silo to extinguish
• Discharge the silo