It is better to prevent waste than to treat or clean up waste after it is formed.
Chemical products should be designed so that at the end of their function they do not persist in the environment and break down into innocuous degradation products.
(Green Chemistry Principles, Dr. Paul Anastas et al)
[We should] eliminate our contribution to systematic increases in concentrations of substances produced by society.
This means systematically substituting certain persistent and unnatural compounds with ones that are normally abundant or break down more easily in nature, and using all substances produced by society efficiently.
(The Natural Step)
It is in the interests of industry to reduce these to a minimum, and
this is best done by reducing the amount of waste generated in the first
place, rather than by treating it afterwards.