For some types of packaging, the best environmental option may be to design the packaging so that energy can be recovered from the waste materials.
To be classed as 'energy recoverable', packaging must generate more energy than that needed to drive the combustion process. To be sure of this 'calorific gain', the net calorific value must be at least 5 megajoules per kilogram.
Types of energy recoverable packaging
The following types of packaging are considered energy recoverable:
- packaging composed of over 50 per cent by weight of organic materials - such as wood, cardboard, paper and other organic fibres, starch and plastics
- thin gauge aluminium foil - up to 50 micrometres thick
Packaging consisting of more than 50 per cent by weight of inorganic material - eg ceramic, glass, clay or metals - may be declared energy recoverable if you can demonstrate that there is calorific gain.
The only design consideration is to ensure that any noxious or hazardous constituents of packaging should have a minimal impact on the environment when it is treated to recover energy. The combined concentrations of lead, cadmium, mercury and hexavalent chromium must not exceed 100 parts per million - see packaging and packaging waste management.