Per the Coastal Fire Centre criteria, a category 3 open burn is defined as:

• Material concurrently in 3 or more piles each not exceeding 2 metres in height and 3 metres in width
  
  
• Material in one or more piles each exceeding 2 metres in height or 3 metres in width
  
  
• One or more windrows, none of which exceed 200 metres in length or 15 metres in width
  
  
• Stubble or grass over an area exceeding 0.2 hectares