Recycled content in construction products

Recycling materials is an essential part of resource efficiency and waste management. To date, it has been relatively difficult for specifiers to determine with much confidence the recycled content by mass of a building product. Comparing products should now be easier with the introduction of an ISO standard that identifies recycled content as part of an environmental product declaration (EPD). The standard calls for data to be calculated and recorded on product data sheets in a clear and consistent fashion.


Recycled content is defined by ISO 14021

ISO 14021 defines recycled content as "the proportion, by mass, of recycled material in a product or packaging. Only pre-consumer and post-consumer materials shall be considered as recycled content, consistent with the following usage of the terms:


Pre-consumer material:

Material diverted from the waste stream during a manufacturing process. Excluded is reutilization of materials such as rework, regrind or scrap generated in a process and capable of being reclaimed within the same process that generated it.


Post-consumer material:

Material generated by households or by commercial, industrial and institutional facilities in their role as end-users of the product, which can no longer be used for its intended purpose. This includes returns of material from the distribution chain." For the purposes of the calculation, the term 'product' refers to the final product as delivered to the construction site and incorporated in the works.



‘Rules of Thumb’ for the calculation and declaration of recycled contents

WRAP have published a guide ‘Calculating and declaring recycled content in construction products’. The guide sets out to provide a set of 'Rules of Thumb' for the calculation and declaration of recycled content in construction products.

The Guide sets out four criteria for the acceptance of material as recycled content within a construction product. A material needs only comply to any one of these criteria to secure its status as recycled content. Whilst compliance to any one is sufficient, where more than one criterion is satisfied, preference is given to criteria A and B in terms of justifying the material status.


Criterion A

Any wastes that are listed in the European Waste Catalogue.


Criterion B

Any material that is classified or intended to be classified as 'waste' within the ISO 14021 definition stated previously. This includes post-construction waste and returns from the distribution chain.


Criterion C

Offcuts or scrap generated within a process where a recovery operation process is required prior to its re-use that changes the physical or chemical nature of the material, e.g. granulation of extruded plastic or crushing of waste blocks.


Criterion D

By-products as defined by the EC Interpretative Communication on waste and by-products. A by-product is defined as a production residue that is not a waste, and a production residue is defined as a material that is not deliberately produced in a production process but may or may not be a waste. In order to be considered a by-product, a production residue must satisfy all of the following three criteria:

• the further use of the residue is not a mere possibility but a certainty;
• the residue does not need any further processing prior to re-use; and
• the residue is produced for further use as an integral part of a continuing process of production.


Further information

Green claims code for products (defra)
• WRAP ( )




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