Chipping can be performed on small round wood (SRW), or mixed brash.  The resultant bulk density will be around 200-400 kg/loose m³, which is less than that of the solid wood, and even packed logs, but more than loose brash. 

With suitable equipment chips may be more easily handled, transported and stored than branches and brash, however SRW and logs should usually be transported before chipping owing to the higher bulk density if stacked properly.

The upcoming standards for solid biofuels in Europe are still under consideration by the Technical Committee CEN/TC 335, which include specifications for wood chips, including:

• Particle size distribution
• Maximum moisture content
• Minimum energy density
• Maximum ash content.

Some individual countries have their own standards that typically define a similar range of parameters.

Stacked wood chips do not allow air to flow easily through the stack. Unless the biomass is very dry this tends to lead to composting and the growth of moulds. Composting leads to loss of biomass and can present a fire hazard owing to the high temperatures created in the core of a large stack.

Advice varies between different sources as to the safe maximum size for stacks of wood chips to minimize the risk of fire, with figures typically around 8-10 m high. The high core temperature in a stack of wood chips can, however, be used to assist drying as moisture is driven out from the core to the periphery.

Spores from moulds growing on piles of stored wood chips have been shown to cause health problems from particle irritation, type I and type II allergic responses, potentially toxic volatile organic compounds (VOCs) and mycotoxins, and inflammatory reactions to cell wall components when inhaled. A P3 filter dust mask should be worn when working in close proximity with stores or deliveries of stored chips.

The choice of chipper used is important if the wood chips are to be used with many types of feed mechanisms, especially auger feeds as found on many wood chip heating systems. Also some wood chip boilers have constraints on the parameters of the wood chips to be used.

General purpose chippers designed primarily for volume reduction do not usually produce chips suitable for use with many auger feeds which require chips of closely defined dimensions, with low levels of fines or slivers. Slivers in particular can cause difficulties as they can bridge or jam the auger.