Plastics definitions

The UK Plastics Pact aligns with UK Government on the definition of plastic packaging used for the purpose of the Plastics Tax. That is:

Plastic means a polymer material to which additives or substances may have been added. Cellulose-based polymers that have not been chemically modified, such as viscose, will not be treated as plastic for the purpose of Plastic Packaging Tax. Other cellulose-based materials which are chemically modified, such as cellulose acetate, will be considered plastic. Additives include materials such as calcium or dyes. When you assess the amount of plastic in a packaging component, the additives are classed as part of the plastic. Plastics include polymers which are:

• biodegradable
• compostable
• oxo-degradable

If a plastic packaging component is made from multiple materials but contains more plastic by weight (including additives which form part of the plastic) than any other substance, it will be classed as a plastic packaging component

In the context of The UK Plastics Pact, plastic is defined as a synthetic polymer of large molecular mass that generally has a linear structure and may include additives for specific characteristics. The source material to manufacture plastics can be either fossil or bio based. Plastics are mouldable, they can be thermoset (moulded once) or thermoplastic (moulded over multiple cycles) and are ‘used for the containment, protection, handling, delivery and presentation of goods, from raw materials to processed goods, from the producer to the user or the consumer.’

In the context of The UK Plastics Pact, cellulose in its natural form without additives is not classed a plastic.

Polymer is defined by EC 1907/2006 3(5) as ‘a substance consisting of molecules characterised by the sequence of one or more types of monomer units. Such molecules must be distributed over a range of molecular weights wherein differences in the molecular weight are primarily attributable to differences in the number of monomer units. A polymer comprises the following:

(a) a simple weight majority of molecules containing at least three monomer units which are covalently bound to at least one other monomer unit or other reactant;
(b) less than a simple weight majority of molecules of the same molecular weight.’

The UK Plastics Pact is aligned to the Ellen MacArthur Foundations’ definition set out in the New Plastics Economy Global Commitment: The proportion, by mass, of post-consumer recycled material in a product or packaging.

This definition aligns with ISO 14021 which post-consumer material as 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. Recycled content commitments as part of the Global Commitment exclude pre-consumer recycled content.

The UK Plastics Pact uses the following list of criteria to identify problematic or unnecessary plastic packaging items:

• Its use is avoidable or reusable options are available.
• It does not commonly enter recycling or composting systems.
• It’s not recyclable or hampers the recycling process.
• It pollutes our environment.

All plastics must comply with Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulations.

The UK Plastics Pact is aligned to the Ellen MacArthur Foundations’ definition set out in the New Plastics Economy Global Commitment: A packaging or packaging component is compostable if it is in compliance with relevant international compostability standards and if its successful post-consumer collection, (sorting), and composting is proven to work in practice and at scale.

Despite definitions being available in EU regulation (Dir2019/904), the term biodegradable is also often misused and applied to a broad range of different materials. Without a specified environment and time frame, the term is extremely vague, because a biodegradable product may biodegrade in some environments and not (in any reasonable timeframe) in others. Importantly, all compostable plastics are biodegradable, but not all biodegradable plastics are compostable. Environments such as in soil, fresh or marine water are not controlled in any way, and therefore the time for a material to biodegrade can vary significantly. The term biodegradable is therefore best avoided as a label for plastic materials as it infers a general behaviour of the material and could mislead users to think that something will automatically biodegrade in a reasonable timeframe.

In the context of the UK Plastics Pact the term biodegradable should not be used unless it can be proved that the packaging will biodegrade in any environment the material is liable to pollute.

Any claims on pack should also state a timeframe to fully decompose based on the environmental conditions providing the longest degradation timescale.

The UK Plastics Pact has adopted the Ellen MacArthur Foundation’s definition of reusable packaging, which in turn aligns with the European Commission definition. An item of packaging can be defined as reusable if it is conceived, designed and marketed to carry out multiple trips in its lifetime by being refilled or reused for the same purpose for which it was conceived.

While packaging may have secondary uses which can be valuable in terms of the circular economy, is not considered reuse by The UK Plastics Pact.

Reusable packaging should be designed to be recyclable as far as possible, as it will inevitably reach the maximum number of reuse cycles at some point, after which recycling ensures the material is kept in the economy.

The UK Plastics Pact is aligned to the Ellen MacArthur Foundations’ definition of reuse set out in the New Plastics Economy Global Commitment: the operation by which packaging is refilled or used for the same purpose for which it was conceived, with or without the support of auxiliary products present on the market, enabling the packaging to be refilled.

The UK Plastics Pact is aligned to the Ellen MacArthur Foundations’ definition set out in the New Plastics Economy Global Commitment: A packaging or packaging component is recyclable if its successful post-consumer collection, sorting, and recycling is proven to work in practice and at scale.

A package can be considered recyclable if its main packaging components, together representing >95% of the entire packaging weight, are recyclable according to the above definition, and if the remaining minor components are compatible with the recycling process and do not hinder the recyclability of the main components. ‘At scale’ is considered a 30% recycling rate.