WM3 Assessments

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WM3 is the Environment Agency’s Technical Guidance document for the classification of waste and to guide WM3 Assessments.


What is WM3?

In 2015 WM2 was superseded by the updated WM3. Both WM2 and WM3 act as guidance concerning anyone involved in producing, managing, transporting, storing, and regulating waste.

WM3 aims to assess any potential hazards in the waste itself and ensures a duty of care around the safe handling of waste.


How Important is the WM3 Guidance?

The identification, classification, and disposal of waste is important, and also a legal requirement.

In the UK over 40 million tonnes of both industrial and commercial waste is generated (annually) from factories, chemical plants, and construction sites. These wastes may potentially display hazardous properties and contain toxins and chemicals that can cause serious illness in humans and animals as well as causing long-lasting pollution and harm to the environment

 As part of your duty of care you must classify the waste your business produces:

  • Before it is collected, disposed of or recovered
  • To identify the controls that apply to the movement of the waste
  • To complete waste documents and records
  • To identify suitably authorised waste management options
  • To prevent harm to people and the environment.

What Is The Difference Between WM2 and WM3?

In 2015 the Environment Agency updated its Technical Guidance document for the classification of waste from WM2 to WM3, with a further update in 2018 for version 1.1.

The biggest changes included the implementation hazard statement codes, which means chemicals in waste now need to be assessed by a new set of criteria. As well as the temperature at which a flammable classification code was amended for some substances.

The potential presence of persistent organic pollutants in waste streams must also now be considered as part of the new WM3. 

The Environment Agencies’ biggest change to WM3 was the updated List of Waste (LoW), which was amended for industries that need to identify different types of waste and their particular hazards.


WM3 Assessments and Waste Classification 

Firstly, it is required to classify the waste and identify its hazardous properties. You need to classify each waste so you can describe it. The classification:

  • must be determined before the waste is moved, disposed of or recovered
  • must be included on waste documents and records
  • determines the controls that apply to the movement of the waste
  • is needed to identify a suitably authorised waste management option


There is a seven-step procedure for waste classification and WM3 Assessments.

Here are the first three steps used to classify waste:

  1. Check if the waste needs to be classified
  2. Identify the code or codes that may apply to the waste
  3. Identify the assessment needed to select the correct code

Here are the steps to assess the waste: 

  1. Determine the chemical composition of the waste
  2. Identify if the substances in the waste are ’hazardous substances’ or ’Persistent Organic Pollutants’
  3. Assess the hazardous properties of the waste
  4. Assign the classification code and describe the classification code


Followed by the four types of ‘class’ under which waste may be categorised:

  • Absolute Non-Hazardous
  • Absolute Hazardous
  • ‘Mirror’ Hazardous; and
  • ‘Mirror’ Non-Hazardous


We’ve written more about the WM3 Assessments process via our supporting WM3 Testing – Levels of Assessment article which outlines the WM3 Testing level including the type and frequency of investigation required.


WM3 Waste Classification and Hazard Identification

Knowledge of which ‘class’ a waste falls under will inform the European Waste Catalogue (“EWC”) classification of the waste. WM3 guidance allows for the correct classification to be made through the quantitative assessment of hazardous properties the waste may display.

The classification of waste must be based on the EU chemical classification legislation, which references the European Classification, Labelling, and Packaging Regulations (CLP). This allows for the identification of hazardous chemicals.

Hazard identification is the process by which information about the intrinsic properties of a substance or mixture is assessed to determine its potential to cause harm. If the nature and severity of an identified hazard meet the classification criteria in the CLP Regulation, a certain hazard class will be assigned to the substance or mixture.

There are hazard classes for physical hazards, health hazards, and environmental hazards.

As part of a WM3 Assessment, the chemical composition of a waste is determined. Based on this chemical assessment, hazardous substances and/or Persistent Organic Pollutants within the waste are identified based on a ‘worst case’ basis. The ‘worst-case’ chemicals are identified based on relevant information regarding the origin and the nature of the waste to be assessed.

The hazardous properties associated with each of the identified determinants are then assessed against relevant threshold values to determine whether the concentrations within the waste material may have the potential to cause a physical, health or environmental hazard.

Given this information, the correct classification code (as described within the EWC), can be assigned to waste with a statistical degree of confidence.


How You Can Adhere To The WM3 Standards?

WM3 guidance must be followed when assessing any chemical constituents with a view to assigning any chemical constituents with a waste classification code and before any waste is moved, recovered, or disposed of, you must make sure all appropriate records and documentation are filled out correctly.

Any construction sites, woodworking facilities, chemical plants, and factories that generate industrial or commercial waste should adhere to the WM3 standards.


WM3 Waste Wood

Currently, there is a focus on waste wood. The EA Regulatory Position Statement (RPS) 207 requires that all waste wood will have to be classified as hazardous unless proven otherwise.

This includes any waste wood that has entered the waste management system and/or has been stockpiled under the RPS. Currently, any unclassified wood waste can only be sent for board manufacture or an IED Chapter IV compliant incineration plant.

The RPS was due to cease on the 31st of July 2020 but has now been extended until 31st January 2021.

After this date, wood waste will have to be classified as hazardous unless a WM3 assessment has been undertaken. A documented WM3 assessment, in accordance with the guidance, would provide the necessary classification.


Experts In WM3 Assessments and Waste Classification

Waste crime has been an issue for many years and regulators in the UK are tasked with now enforcing this guidance. An EWC waste classification code cannot simply be applied without having carried out a WM3 Assessment, which should be documented.

ECL can offer our expertise to ensure that we quickly identify hazards in our client’s waste and then classify them in line with WM3 Guidance and regulation.

We are able to identify suitably authorised waste management options. If the waste is classified as non-hazardous then suitable end-use for the waste may be identified. For example, waste wood from a manufacturing process could be used for a biomass boiler fuel.

ECL service all project sizes from small business to large corporate infrastructure projects.

Fill out our ECL Enquiry Form or call us on 01443 801215 for any queries regarding Planning Applications, WM3 Assessments, WAC Testing, Waste Classification, and Site Investigation Surveys