Hay and Harvest Fire Safety

Spontaneous ignition is the leading cause of haystack fire in Victoria, and just one damp bale is enough to ignite a haystack.


hayHaystack fires

Green or damp hay encourages elements like bacteria and fungi to grow and decompose. A series of complex biological and chemical reactions can then cause a build-up that allows hay to heat. This can produce flammable gasses which may ignite.

Haystack fires are also caused by sparks from machinery and equipment, and embers from burn offs or bushfires.


To prevent haystack fires:

  • Ensure hay is fully cured before baling
  • Know the history of the hay you purchase
  • Keep haystacks to a limited size
  • Store:
    • In separate stacks
    • In a number of places away from key assets
    • Away from possible sources of ignition (roadsides, powerlines workshops and vegetation). Never store vehicles, machinery and equipment in your hayshed - there is increased risk of losing both hay and machinery
    • In areas that are not likely to flood and in sheds that are in good repair to minimise the moisture content
  • Consider using temporary fencing to allow stock to graze close to hay and silage stores to reduce fuel loads near these assets
  • Don't stack hay right to the top of a hay shed. Allow some air to circulate at the top - this helps to carry away moisture
  • Protect hay from rain, leaking roofs and spouts and cover stacks with tarps or hay caps
  • Monitor hay with a correctly calibrated moisture meter. Moisture content should be no more than 20 per cent (12 - 18 per cent is recommended as a precaution).

If hay gets too hot

  • Spread out the stack to allow to cool.
  • Don't walk on top of hay that is heating as it may collapse or ignite.
  • Don't feed to animals. The heating process reduces the nutrient quality of the hay.

Hay cutting and carting

  • Your vehicle's exhaust system should have:
    • A fire-resistant cover on the load
    • A spark shield, OR
    • Be located under the body of the vehicle so emissions are away from the hay.
  • Be conscious of hot exhaust in contact with long dry grass

See also:

Preventing Haystack Fires (PDF 100.6KB)



Preventing Harvest Fires

How can farmers approach their harvest season with the aim of reducing their own risk of fire and avoiding the devastating economic consequences of fire? What are the factors that consistently contribute to harvest fires - particularly those involving headers?

Kevin had been reflecting on his own personal experience of harvest fires on his land and his neighbours properties. With time on his hands, Kevin undertook research to understand common causes of harvest fires, new farming technology and new ways farmers can protect their land and livestock from fires during harvest season.

Kevin’s research involved reports from the USA, Europe and Australia. He had discussions with West Australian-based agricultural publisher Kondinin Group and visited a number of farmers in the Wimmera. Armed with this research, Kevin approached his farming neighbours to assist in trialling techniques and equipment that he had researched. They experimented with harvesting in paddocks at different angles and speeds, depending on wind direction, as well as riding in the back of a header to observe the interactions between dust and potential heat sources such as the manifold.

Kevin was able to ascertain the point of ignition and the factors contributing to a fire starting within the header engine. This video shares information on mechanics, weather conditions, tiers of emissions, heat sources, Voluntary Harvest Guidelines, recommended practices for operators, property owners’ responsibilities, insurance and harvest fire planning.


In this video retired Farmer and CFA Volunteer Kevin Bolwell, of Horsham in Victoria’s Wimmera region, explains the findings of his research into header fires and provides practical advice for farmers and harvesting contractors.

Thank you for watching, you are invited to participate in a short survey. The survey will take approximately 5 minutes to complete. All responses will not be linked or identifiable to those participating in the survey.

The purpose of this survey is to collect feedback from the public to improve the quality of the Country Fire Authority’s (CFA’s) Farm Fire Safety initiative in Victoria.



Page last updated:  Monday, 11 October 2021 5:06:25 PM