This is a great discussion.
When a designer is planning to develop a “sustainable product,” what should be the goal?
Using recycled content is a great place to start, but this single definition of a sustainable product is incomplete. For example, recycled content can be subject to contamination by toxic heavy metals, coatings, colorants (e.g., chlorinated pigments in green, red or yellow printing inks) or other additives from its previous application.
This is where an ounce of prevention can readily surpass a pound of cure. In addition to looking back in time (up the supply chain) for a recycled material -- requiring the supplier to document the chain of custody and previous application of the material, verifying ingredient formulation to the greatest extent possible, and testing for the most likely contaminants -- a designer also should look forward in time, and design the next application to enable future recycling of the material. Components within a product should be combined in a way that facilitates easy disassembly after the use phase, to divide the materials into their separate recycling streams.
Ideally, a designer also should collaborate with other organizations -- governments managing public recycling systems, companies that collect and haul discarded materials, processors of recovered materials, manufacturers or suppliers that could use the material in the future, and others -- to help enhance the system to recover the product after its use and recycle its component materials.
Product sustainability cannot be judged by a single attribute, such as recycled content, ingredient composition or recycling used materials, when such items are inextricably linked and should be intentionally developed to work together as effectively as possible.