The hierarchy of waste management, places waste reduction at the top, followed by re-use, recycling, recovery and finally disposal. Waste reduction is synonymous with waste prevention or waste minimization and has been defined as any technique, process or activity which either avoids, eliminates or reduces a waste at its source, usually within the confines of the production unit.
This is sometimes known as ‘clean technology’ or producing ‘clean’ products. Clean technology is about minimizing the environmental impact of releases from processes. The philosophy behind it is the prevention of waste rather than the cure. Every aspect of a process needs to be optimized to minimize waste in any form.
The basic options to achieve this philosophy are relatively few and can be summarized in order of preference as:
Reduction at Source: The most effective way to prevent a material from entering the environment is to stop using or making it.
Product Changes: Suitable alternative materials that may perform the same function with less environmental consequences.
Process Changes: A process should be designed or changed in such a way that potentially polluting materials are not made or isolated, minimizing the possibility of a release.
Re-use of a material is an alternative way of preventing release to the environment.
On-site Recycling: Using a by-product of one process as a raw material for another disposes of it without an environmental impact.
Off-site Recycling: Sending a by-product of a process to be used elsewhere is similar to on- site recycling, but the pollution and cost of transport, handling, etc. makes this less desirable.