These criteria used for defining green products was excerpted from "Building Materials: What Makes a Product Green?" as featured by Environmental Building News.
The materials used to produce a building product and where those materials came from is a key determinant of green.
Whenever we can reuse a product instead of producing a new one from raw materials, even if those raw materials are recycled, we save on resource use and energy. Many salvaged materials used in buildings (bricks, millwork, framing lumber, plumbing fixtures, and period hardware) are sold on a local or regional basis by salvage yards. Fewer salvaged materials are marketed widely, and it is generally only these that are profiled in a national directory such as GreenSpec. Local and regional green product directories can really shine when it comes to finding salvaged materials.
Recycled content is an important feature of many green products. From an environmental standpoint, post-consumer is preferable to pre-consumer recycled content, because post-consumer recycled materials are more likely to be diverted from landfills. For most product categories, there is currently no set standard for the percentage of recycled content required to qualify for inclusion in GreenSpec, but such standards will increasingly be developed in the future.
In some cases, products with recycled content are included with caveats regarding where they should be used. Rubber flooring made from recycled automobile tires is a good example, the caveat is that these products should not be used in most fully enclosed indoor spaces due to offgassing concerns.
In certain situations, from a life-cycle perspective, recycling has downsides. For example, energy consumption or pollution may be a concern with some collection programs or recycling processes. Also, closed-loop recycling is generally preferable to downcycling, in which a lower-grade material is produced. As more complete life-cycle information on recycled material and the process of recycling becomes available, we intend to scrutinize recycled products more carefully.
Pre-consumer (also called post-industrial�) recycling refers to the use of industrial by-products, as distinguished from material that has been in consumer use. Iron-ore slag used to make mineral wool insulation, fly ash used to make concrete, and PVC scrap from pipe manufacture used to make shingles are examples of post-industrial recycled materials. Usually excluded from this category is the use of scrap within the same manufacturing process from which it was generated, material that would typically have gone back into the manufacturing process anyway. While post-consumer recycled content is better than pre-consumer recycled content, the latter can still qualify a product for inclusion in GreenSpec in many product categories, especially those where there are no products available with post-consumer recycled content.
A number of products are included in GreenSpec because they are derived from agricultural waste products. Most of these are made from straw, the stems left after harvesting cereal grains. Citrus oil, a waste product from orange and lemon juice extraction, is also used in some green products, but such products usually include other agricultural oils as well and are lumped under 2d - Rapidly renewable products.