Wastes from mechanical treatment of waste: how to classify
Source: gov.uk (2025-05-01)

Waste codes for common wastes produced by mechanical treatment at a waste management facility.

You must classify the waste your business produces before it is collected, disposed of or recovered (https://www.gov.uk/dispose-business-commercial-waste).

You must do this to identify:
- if the waste is hazardous or not
- which controls apply to the movement of the waste - this is to prevent harm to people and the environment
(*) An asterisk at the end of a code means the waste is hazardous.

Vehicle and metal shredder residues

Bulky metal wastes can be recycled through a shredding process. This breaks the waste into small pieces. Magnets may be used to remove ferrous metals.

Other heavy fractions, including non-ferrous metals, are separated out and sent for more treatment. This leaves a residue made of mostly light, low density materials.

This light fraction is described as ‘fluff’, ‘frag fluff’, ‘light fraction’ or similar.

This residual fraction is also called metal shredder residue (MSR). When produced from vehicle shredding, it’s also called automotive shredder residue (ASR).

Classify this using the following codes.

More treatment of ASR and MSR to segregate the components of the waste produces post shredder treatment (PST) residues. The way you code PST residues depends on the treatment processes. But if this treatment does not include shredding, then it’s likely you should classify this waste as a mixed waste from mechanical treatment.

Mixed wastes from mechanical treatment

The mechanical treatment of wastes can result in a range of outputs. These may be hazardous, non-hazardous or both. You must assess your waste to work out if it has any hazardous properties.

A common example of a mixed waste from mechanical treatment is the residual fraction from the trommelling of construction and demolition waste (also called trommel fines). This residual fraction commonly contains a mixture of soils, aggregates, plastic, wood and metal.

These are some examples of codes for mixed waste from mechanical treatment.

Segregated wastes

You must only use these waste codes for single streams of waste. This means that they have been appropriately separated from other wastes. If your waste contains more than one waste type (such as glass, paper and plastic) then your waste is mixed and you cannot use these codes.

Minerals

For waste classification, ‘minerals’ means naturally occurring materials such as sand and stone.

Minerals produced from the treatment of aggregates must not include:
- human-made (anthropogenic) wastes such as bricks, concrete, tiles and ash
- non-mineral wastes
Refuse derived fuels

Refuse derived fuel is waste that has been treated to be suitable for use as fuel. It must meet the specification for the facility where it is sent for use. This may include requirements for the calorific value, chlorine content and biogenic (made by or of plants and animals) content.

Do not classify waste as 19 12 10 if it:
- requires more processing before it can be used as a fuel
- does not go for use as a fuel
How to classify other wastes

Check the guidance on how to classify other common waste types (https://www.gov.uk/government/collections/classify-different-types-of-waste).

Or check the technical guidance on waste (https://www.gov.uk/government/publications/waste-classification-technical-guidance), which lists all of the waste codes and how to apply them.

Get advice from a specialist waste contractor if you are not sure what code to use for your waste.

For more information, contact the Environment Agency.

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