In the cradle-to-cradle model, all materials used in industrial or commercial processes—such as metals,
fibers,
dyes—fall into one of two categories: "technical" or "biological" nutrients. •
Technical nutrients are strictly limited to non-toxic, non-harmful synthetic materials that have no negative effects on the natural environment; they can be used in continuous cycles as the same product without losing their integrity or quality. In this manner these materials can be used over and over again instead of being "
downcycled" into lesser products, ultimately becoming
waste. •
Biological nutrients are
organic materials that, once used, can be disposed of in any natural environment and
decompose into the soil, providing food for small life forms without affecting the natural environment. This is dependent on the ecology of the region; for example, organic material from one country or landmass may be harmful to the ecology of another country or landmass. • Material health, which involves identifying the chemical composition of the materials that make up the product. Particularly hazardous materials (e.g. heavy metals, pigments, halogen compounds etc.) have to be reported whatever the concentration, and other materials reported where they exceed 100 ppm. For wood, the forest source is required. The risk for each material is assessed against criteria and eventually ranked on a scale with green being materials of low risk, yellow being those with moderate risk but are acceptable to continue to use, red for materials that have high risk and need to be phased out, and grey for materials with incomplete data. The method uses the term 'risk' in the sense of hazard (as opposed to consequence and likelihood). • Material reutilization, which is about recovery and recycling at the end of product life. • Assessment of energy required for production, which for the highest level of certification needs to be based on at least 40% renewable energy for all parts and subassemblies. • Water, particularly usage and discharge quality. • Social responsibility, which assesses fair labor practices.
Health Currently, many human beings come into contact or consume, directly or indirectly, many harmful materials and chemicals daily. In addition, countless other forms of plant and animal life are also exposed. C2C seeks to remove dangerous
technical nutrients (synthetic materials such as
mutagenic materials,
heavy metals and other dangerous chemicals) from current life cycles. If the materials we come into contact with and are exposed to on a daily basis are not toxic and do not have long term health effects, then the health of the overall system can be better maintained. For example, a fabric factory can eliminate all harmful
technical nutrients by carefully reconsidering what chemicals they use in their dyes to achieve the colours they need and attempt to do so with fewer base chemicals. Following C2C design principles, product manufacture can be designed to cost less for the producer and consumer. Theoretically, they can eliminate the need for
waste disposal such as landfills.
Definitions •
Cradle to cradle is a play on the phrase "cradle to grave", implying that the C2C model is sustainable and considerate of life and future generations. •
Technical nutrients are basically
inorganic or synthetic materials manufactured by humans—such as plastics and metals—that can be used many times over without any loss in quality, staying in a continuous cycle. •
Biological nutrients and materials are
organic materials that can decompose into the natural environment, soil, water, etc. without affecting it in a negative way, providing food for bacteria and microbiological life. •
Materials are usually referred to as the building blocks of other materials, such as the dyes used in colouring fibers or rubbers used in the sole of a shoe. •
Downcycling is the reuse of materials into lesser products. For example, a plastic computer case could be downcycled into a
plastic cup, which then becomes a park bench, etc.; this eventually leads to
plastic waste. In conventional understanding, this is no different from
recycling that produces a supply of the same product or material. •
Waste = Food is a basic concept of
organic waste materials becoming food for bugs, insects and other small forms of life who can feed on it, decompose it and return it to the natural environment which we then indirectly use for food ourselves.
Existing synthetic materials The question of how to deal with the countless existing
technical nutrients (synthetic materials) that cannot be recycled or reintroduced to the natural environment is dealt with in C2C design. The materials that can be reused and retain their quality can be used within the technical nutrient cycles while other materials are far more difficult to deal with, such as plastics in the
Pacific Ocean. ==Hypothetical examples==