The Circular Economy Glossary – Part 2

Part 1 covered the building blocks: core concepts, material flows, design principles, and value retention strategies. Now we widen the lens to explore how circular economy thinking extends beyond individual products into entire systems. Part 2 covers biological processes that return materials safely to nature, the policies and business models that make circularity viable at scale, and the standards that create shared language across industries and borders.

1) Biological Processes and Regeneration

1. Composting

   Microbial breakdown of organic matter with oxygen to create compost.
   Example: Turning cafeteria waste into compost for garden beds.

2. Anaerobic digestion

   Microbial breakdown of organic matter without oxygen that produces biogas and digestate.
   Example: Food scraps processed to create usable gas and soil enhancers.

3. Regenerative production

   Producing food and materials in ways that support positive outcomes for nature such as healthier soils and biodiversity.
   Example: Agroforestry that supplies fibre while restoring soil health.

2) Systems, Policy, and Procurement

1. Reverse logistics

   Moving used products, parts, and materials back to producers or specialists for recovery actions.
   Example: A take-back service that collects old units during installation.

2. Extended Producer Responsibility (EPR)

   A policy approach that extends a producer’s financial and operational responsibility to the post-consumer stage of a product’s life.
   Example: A brand funds nationwide collection and certified recycling.

3. Producer Responsibility Organisation (PRO)

   A collective body that manages EPR obligations on behalf of producers.
   Example: Multiple brands pay a PRO to operate collection and sorting centres.

4. Circular procurement

   Buying that prefers durability, repairability, recycled content, service models, and verified end of life.
   Example: Tenders that require spare parts availability and a take-back plan.

5. Resource efficiency

   Using materials and energy efficiently through the whole life cycle.
   Example: Right sizing equipment so it runs at optimal load.

6. Decoupling

   Improving well-being and economic value without matching increases in resource use or environmental impact.
   Example: Serving more customers with the same footprint through higher utilisation.

7. Renewable energy

   Energy from sources that are not depleted on economic timescales.
   Example: Solar and wind powering facilities.

3) Materials and Inputs

1. Primary materials

   Also called virgin materials. Raw materials extracted from nature that have not been previously used.
   Example: Newly mined bauxite for aluminium.

2. Secondary materials

   Also called recycled materials. Materials recovered from previous use cycles and reintroduced into manufacturing.
   Example: Recovered plastics pelletised for new mouldings.

3. Renewable materials

   Biobased materials that regenerate within a human time frame when managed responsibly.
   Example: Certified bamboo used for fittings.

4) Business Models

1. Sharing or sharing models

   Use of a product by multiple users to increase utilisation and retain value.
   Example: A tool library that serves many small businesses.

2. Product as a Service (PaaS)

   Customers pay for performance rather than ownership. The provider handles upkeep, upgrades, and end of life.
   Example: Equipment on subscription with maintenance included.

3. Industrial symbiosis

   Organisations exchange energy, water, or by-products so one firm’s waste becomes another’s input.
   Example: Heat from one facility used to warm a neighbouring workshop.

5) Standards and Roadmaps

1. ISO 59004

   An international standard that sets out shared vocabulary, principles, and guidance for the circular economy.
   Example: Teams use the same terms across procurement and operations.

2. BS 8001

   Guidance that helps organisations apply circular principles in practice.
   Example: A company uses it to shape internal policies and targets.

3. EU Circular Economy Action Plans

   Policy roadmaps that influence product design, waste prevention, and secondary materials markets across the life cycle.
   Example: Suppliers align packaging with rules that favour recyclability and reuse.

Putting It All Together

Between Part 1 and Part 2, you now have a practical reference that spans product design, material recovery, system-level policies, and forward-thinking business models. The circular economy is not a single fix but a shift in how we design, make, use, and recover value. Whether you are writing a tender, briefing a team, or simply trying to make sense of sustainability jargon, these definitions give you a common language to move from aspiration to action.