Safe use of biomass boilers

22 November 2020

As renewable energy technology develops, biomass is increasingly viewed as a green alternative to traditional forms of energy.

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How biomass boilers work

A biomass boiler uses renewable resources fuels such as wood fuel (pellets, chips, logs and forestry material). rather than fossil fuels. It produces energy to heat water that is then distributed via a low pressure water system around the building. 
Biomass generates power, produces heat and can be used in combined heat and power plants.

Dangers of biomass

  • When using wood chips, there is a potential risk of spontaneous ignition causing a fire if microbial activity occurs.
  • When using wood pellets, they can produce dust during delivery, transport and storage periods. This can enhance the explosion risk. 
  • Carbon monoxide poisoning can be caused by poor ventilation or improper use of biomass boilers.

Biomass boiler maintenance requirements

Due to the explosive nature of wood dust used in biomass boilers, there may be a requirement to meet the legislative requirements of The  Explosive Atmospheres at Places of Work Regulations where biomass heating is being used in a workplace. 

  • Wood chip need to be turned regularly to reduce the risk of spontaneous ignition occurring.
  • Use good quality pellets with a low dust content and good mechanical durability.
  • Areas associated with the biomass boiler equipment, including fuel storage areas and boiler house, need to be swept out and cleaned down at least weekly and all combustible waste removed.
  • Dust build up must be kept to a minimum and you must ensure no ignition sources (e.g. smoking, fires or naked flames) are used near the storage areas.
  • Ensure zones are created to contain dust within the fuel store so that it cannot escape between the fuel store and boiler room. In some situations, an explosion relief panel may be appropriate.
  • All plant and equipment must be inspected, serviced and maintained as per the manufacturer’s recommendations.
  • All work must be undertaken by an approved and qualified engineer. 

Health and safety for biomass boilers

You should take steps to make your biomass boiler safe for both employees and visitors.

  • If possible, the boiler should be located in a self-contained external building of non-combustible construction. 
  • Only trained personnel should be authorised to access the area.
  • Appropriate signage should be used to warn people of the danger and access restrictions. 
  • Adequate ventilation should be provided in the storage area.
  • A dry powder fire extinguisher should be present at all times. 
For detailed guidance on how to manage risks from biomass boilers read our biomass boiler guidance notes.