A pollution prevention is techniques that eliminate waste prior to treatment, such as by changing ingredients in a chemical reaction.
Other /More definition:
A Pollution Prevention is a strategy that emphasizes reducing the amount of pollution or waste created, rather than controlling waste or dealing with pollutants after they have been created
Other /More definition:
Pollution prevention is the device or process that prevents a potential pollutant from forming or entering the environment or sharply reduces the amount entering the environment. Compare pollution cleanup.