Although these five purchasing principles are intended for government entities and their subcontractors, these guidelines are useful for manufacturers and builders alike.

1. Three-part harmony: Weigh three criteria with every purchase: impact on the environment, price, performance. Make environmental considerations part of normal purchasing practice, consistent with such traditional factors as product safety, price, performance, and availability.
   
   
2. Pollution prevention: Root every purchase in the ethic of pollution prevention, which strives to eliminate or reduce, upfront, potential risks to human health and the environment.
   
   
3. Life cycle perspective/multiple attributes: measure a product or service's environmental preferability using several attributes from a life cycle perspective, not a single attribute such as the amount of recycled content in a product.
   
   
4. Comparison of environmental impacts: Consider the reversibility and geographic scale of the environmental impacts of using this product, material or service, the degree of difference among competing products or services, with special consideration to protecting the health of workers and end users.
   
   
5. Environmental performance information: Insist on comprehensive, accurate, and meaningful data about the environmental performance of products or services you are considering purchasing.