Last reviewed 6 February 2018
Caroline Hand gives a practical guide to classifying waste, and emphasises the importance of any waste producer complying with their legal duty of care, in order to avoid prosecution.
Even with the best efforts to manage resources efficiently, every business will end up with some unwanted materials which need to be taken off site. It is essential to know whether these fall within the legal definition of “waste” or “hazardous waste”. If they do, the waste producer has a legal duty of care and can be prosecuted if the waste is not managed in compliance with all the relevant legislation. For example, all waste must be accompanied by a transfer note (non-hazardous waste) or consignment note (hazardous waste), which must carry an accurate and detailed description of the waste. Waste can only be transported by a waste carrier who is registered with the environmental regulator (the Environment Agency, SEPA or NRW). This article gives a practical first point of reference on waste classification: for a more detailed guide, see the Croner-i waste topics Waste Definitions, Duty of Care, Duties under the Hazardous Waste Regulations and Assessment of Hazardous Waste.
Waste or non-waste?
Anything which has been put in a skip or bin is obviously waste but what about useful materials such as wood, rubble, old furniture or empty containers which may be of value to someone else and are taken away for reuse or recycling?
The EU Waste Framework Directive, on which UK waste legislation is based, defines waste as anything which has been discarded by the holder. The definition excludes radioactive waste, sewage effluent and emissions to air, which are covered by separate regulatory regimes and harmless natural materials such as manure.
If an item can be directly reused without any significant repair or refurbishment and is given to charity, sold second hand or exchanged — eg on a platform like WARPit — it is not waste. However, if a serviceable item is put in a skip or left for collection by a waste contractor, it is waste, since you have discarded it. Recyclable materials which need to be reprocessed, such as waste paper, waste cooking oil, scrap metal or plastic bottles, will always be classified as waste, as will damaged items such as broken pallets which need repair. Unwanted materials which are going to be burned as fuel — such as waste oils or solvents — are also waste.
Reusable construction materials such as clean rubble can be something of a grey area. If they are being directly reused within your business, they are not waste, but if another company removes them, they are likely to be regarded as waste.
Hazardous or non-hazardous waste?
Hazardous waste presents risks to the environment and to human health, so is much more tightly regulated than non-hazardous waste. The focus of the legislation is on chemical hazards and biohazards rather than the risk of physical injury. Waste such as broken glass or uncontaminated sharps, which might be regarded as a hazard in a health and safety risk assessment, is not “hazardous waste” for the purpose of the legislation, whereas a very small amount of toxic chemical residue in a container would qualify as “hazardous waste”.
In Scotland, hazardous waste is known as special waste, but it is assessed in exactly the same way.
Step 1: Does it fall within common categories of hazardous waste?
Before embarking on the classification procedure, which is quite complex, it is worth noting that the following commonplace waste streams are almost invariably hazardous:
anything containing asbestos
waste agrochemicals (eg weedkiller)
fluorescent light tubes
old computer monitors (with cathode ray tubes (CRTs))
waste engine oils
cleaning or DIY products which carry a white warning diamond (eg bleach), even if there is only a small amount left in the container
infectious clinical waste, eg soiled dressings and sharps from people who have an infection. (This does not include sanitary products, nappies, etc from healthy people.)
Step 2: Is it “absolute hazardous”?
The hazardous waste assessment procedure is set out in the Environment Agency’s guidance note WM3 Waste Classification: Guidance on the Classification and Assessment of Waste (2015), which is downloadable free of charge from its website.
The list of wastes
Appendix A to WM3 is a catalogue of waste types, known as the European Waste Catalogue (EWC) or List of Wastes (LoW). The EWC lists both hazardous and non-hazardous wastes, assigning a six-digit code to each waste stream. Hazardous waste entries are denoted with an asterisk.
Before carrying out any kind of chemical analysis and assessment, waste producers should consult the list. There are four types of entry:
Absolute hazardous — coded red.
Absolute non-hazardous — coded black.
Mirror hazardous — coded blue.
Mirror non-hazardous — coded green.
For an absolute hazardous waste, there is only one entry. Mirror entries are paired: there are two entries for the same category of waste, one “mirror hazardous” and one “mirror non-hazardous”.
If a waste stream is “absolute hazardous” then no further analysis or calculation is required: the waste is definitely hazardous. This applies particularly to hazardous articles such as CRTs and NiCd batteries.
Step 3: What hazardous substances does it contain?
If the waste stream is “mirror hazardous” then the assessor must carry out the assessment procedure set out in WM3. This is normally carried out by a specialist waste contractor or chemist, on behalf of the waste producer. For physical hazards such as flammability, testing will be required.
Assessors need to know whether the waste contains any of the hazardous substances listed in EC Regulation 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures. This is the same regulation which governs the labelling of hazardous chemical products. The easiest way to find out whether a specific chemical is hazardous is to use the ECHA search engine.
This database will give the Hazard Class and Hazard Statements for the chemical of concern.
The assessor must find out:
which hazardous substances are present in the waste stream
the concentration in which they are present.
Step 4: What is the concentration of the hazardous substances?
Waste is hazardous if it possesses one or more of the 15 Hazardous Properties (HPs) listed in the directive.
Specific target organ toxicity (STOT) and aspiration hazard
Releases toxic gases
After disposal, produces a hazardous leachate, etc
If the concentration of a hazardous substance exceeds the appropriate threshold laid down in WM3, the whole waste stream has an HP. WM3 lists the threshold concentrations for each hazardous property, which are summarised in the table below.
So, for example, if a waste stream contains a substance which is classified as a skin sensitiser with Hazard Statement H317, the waste stream will be hazardous if the concentration of the sensitising substance exceeds 10%.
It is the concentration, not the quantity that matters: very small quantities of hazardous substances still qualify as hazardous waste when discarded.
Appendix C of WM3 contains a series of chapters, one for each of the HPs. These include flowcharts to help assessors to decide whether a waste stream displays that particular hazard.
HP1, HP2, HP3
Testing required: see WM3 chapters C1, C2, C3
H315 and H319
HP5 Aspiration toxicity
HP6 Acute toxicity 1 (ingestion)
HP6 Acute toxicity 2 (ingestion)
HP6 Acute toxicity 3 (ingestion)
HP6 Acute toxicity 4 (ingestion)
HP6 Acute toxicity 1 (dermal)
HP6 Acute toxicity 2 (dermal)
HP6 Acute toxicity 3 (dermal)
HP6 Acute toxicity 4 (dermal)
HP6 Acute toxicity 1 (inhalation)
HP6 Acute toxicity 2 (inhalation)
HP6 Acute toxicity 3 (inhalation)
HP6 Acute toxicity 4 (inhalation)
HP7 Carcinogenic 1A, 1B
HP7 Carcinogenic 2
No thresholds: see WM3 Chapter C9
HP10 Reprotoxic 1A, 1B
HP10 Reprotoxic 2
HP11 Mutagenic 1A, 1B
HP11 Mutagenic 2
HP12 Releases toxic gas
Specific thresholds depending on hazardous substance
HP13 Skin sensitiser 1, 1A, 1B
HP13 Respiratory sensitiser 1, 1A, 1B
HP14 Ecotoxic (ozone depleting)
H400, H410, H411, H412
Use old Risk Phrase method or equations in WM3 Chapter C14
HP15 Indirect hazard
H205, EUH001, EUH019, EUH044
Presume hazardous unless testing proves otherwise
PCDD and PCDF (dioxins and furans)
All other listed Persistent Organic Pollutants (POPs)
Key to Hazard Statements
Causes severe skin burns and eye damage
Causes skin irritation
Causes serious eye damage
Causes serious eye irritation
Causes damage to organs
May cause damage to organs
May cause respiratory irritation
Causes damage to organs through prolonged or repeated exposure
May cause damage to organs through prolonged or repeated exposure
May be fatal if swallowed and enters airways
Fatal if swallowed
Toxic if swallowed
Harmful if swallowed
Fatal in contact with skin
Toxic in contact with skin
Harmful in contact with skin
May cause an allergic skin reaction
Fatal if inhaled
Toxic if inhaled
Harmful if inhaled
May cause allergy or asthma or breathing difficulties if inhaled
May cause cancer
Suspected of causing cancer
May damage fertility or the unborn child
Suspected of damaging fertility or the unborn child
May cause genetic defects
Suspected of causing genetic defects
Very toxic to aquatic life
Very toxic to aquatic life with long-lasting effects
Toxic to aquatic life with long-lasting effects
Harmful to aquatic life with long-lasting effects
May cause long-lasting effects to aquatic life
Harms public health and the environment by destroying the ozone in upper atmosphere
May mass explode in fire
Explosive when dry
May form explosive peroxides
Risk of explosion if heated under confinement
Is this waste acceptable in landfill — and if so, must it go to a “hazardous landfill”?
Any waste going to landfill needs to meet the waste acceptance criteria (WAC) established under the EU Landfill Directive. These criteria mainly relate to the presence of hazardous substances which might leach out in landfill. If the leaching of hazardous substances in a laboratory test exceeds the specified threshold levels, the waste will not be acceptable for landfill and some alternative treatment or disposal method must be found. Even though a landfill site may have a permit to take hazardous waste, it cannot accept a waste stream which does not meet the “hazardous WAC”.
The WAC for hazardous waste landfill are very detailed and substance-specific. Any assessment of these would be done by a specialist analytical laboratory.
In the normal way, inert wastes such as brick, concrete and stone from demolition work do not require testing and can be sent directly to an inert landfill. However, if there is a possibility that the waste might be contaminated with materials such as oils, chemicals, plastic or asbestos it must be tested and evaluated against the WAC. There are specific WAC for inert waste. A full table of WAC can be found in Council Decision 2003/33/EC but the WAC which relates specifically to contamination with organics — the type of waste most frequently of concern to businesses — are reproduced in the table below.
Total organic carbon
Benzene, toluene, ethylbenzene, xylenes
polycyclic aromatic hydrocarbons (PAHs)
So, for example, if a sample of waste is contaminated with oil at a concentration exceeding 500mg/kg, this waste will not be accepted in an inert landfill. You may still be able to send it to a specialist hazardous waste landfill, but it will only be accepted in a hazardous waste landfill if the total organic carbon does not exceed 6% prior to treatment.
Testing for WAC is the responsibility of the waste producer, who must commission a basic characterisation: a detailed report on the properties and chemical composition of the waste. Working in collaboration with the waste management contractor, the waste producer will be responsible for regular compliance testing to make sure that future skiploads of waste conform to the description in the basic characterisation. On top of this, the landfill site operator will carry out spot checks. Details of the sampling and testing requirements can be found in the Environment Agency’s guidance document Waste Sampling and Testing for Disposal to Landfill.
Further information on the WAC can be found in the Croner-i topic Landfill.
Active or inactive waste?
There is one further classification system for waste, which relates solely to the landfill tax. Waste destined for landfill must be classified as active or inactive. This distinction is important because inactive waste attracts a much lower rate of landfill tax. Active waste is essentially biodegradable waste, whereas inactive waste is basically inert construction and demolition waste — but the criteria used are not the same as those used for WAC. HMRC has published detailed guides to landfill tax, available on its website, and a brief summary is given in the Croner-i’s Waste Management looseleaf book.