Persistent Organic Pollutants (POPs) in Waste

What are POPs?

  • POPs are complex organic compounds that are resistant to degradation through chemical, biological and photolytic means, therefore remain in the environment for long periods of time.
  • The POPs most people would be aware of include pesticides (such as DDT) and PCBs (polychlorinated biphenyls) which are used in industrial processes, such as electrical transformers.
  • Unintentional POPs can be produced by uncontrolled combustion of wastes, these include dioxins and furans.

Regulation of POPs

Both chemical and waste regulations apply to POPs. For example from chemical legislation POPs are also classed as PBTs (Persistent, Bioaccumulative and Toxic) or TOMPs (Toxic Organic Micro Pollutants).

In December 2007 the UK introduced the POPs Regulations (2007) based on Annex IV of Regulation (EC) No 850/2004. Producers disposing or treating wastes, as part of their ‘duty of care’, are required to classify their waste in line with Technical Guidance WM3.

Who does this apply to?

The Stockholm Convention from May 2001 is designed to eliminate/restrict the listed POPs. The list has been amended over the years and the complete list is shown in Table 1, including concentration limits, which are now less stringent for the majority of POPs.

Why are we testing for them?

Waste processors have permit conditions that require monitoring of certain parameters such as dioxins/furans and PCBs for compliance reporting. Some waste producers may not be aware that they are required to classify their waste or what parameters they need to test for.

New Regulations came into force on 30 September 2016, which introduce the new POP of hexabromocyclododecane (HBCDD or HBCD). Specific wastes are mentioned in the text and these include:

  • Wastes from thermal treatment processes;
  • Construction and demolition wastes (including excavated soil from contaminated sites); and
  • Wastes from waste management facilities, off-site waste water treatments plants and the preparation of water intended for human consumption and water from industrial use.

How can we help?

If you require assistance in classifying waste WRc can help. We understand how to complete robust waste classifications to the latest Technical Guidance.  This includes preparing robust sampling plans, managing multi-laboratory testing programmes, interpreting data and providing recommendations for future testing. For example, WRc completed a study for DEFRA to quantify the concentrations polybrominated diphenyl ether flame retardants (PBDEs) present as individual congeners, which can be found here.

Table 1 – Current POPs required for waste classification

Substance Concentration limit (mg kg-1) unless otherwise stateda Maximum concentration limit (mg kg-1)b
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF)c 5 µg kg-1 5
DDT (1,1,1-trichloro-2,2-bis (4-chlorophenyl)ethane) 50 5 000
Chlordane 50 5 000
Hexachlorocyclohexanes, including lindane 50 5 000
Dieldrin 50 5 000
Endrin 50 5 000
Heptachlor 50 5 000
Hexachlorobenzene 50 5 000
Chlordecone 50 5 000
Aldrin 50 5 000
Pentachlorobenzene 50 5 000
Polychlorinated Biphenyls (PCBs)d 50 50
Mirex 50 5 000
Toxaphene 50 5 000
Hexabromobiphenyl 50 5 000
Endosulfan 50 5 000
Hexachlorobutadiene (HCBD) 100 1 000
Polychlorinated naphthalenes (PCN) 10 1 000

Alkanes C10-C13, chloro (short-chain chlorinated paraffins)  (SCCPs)
CxH(2x-y+2)Cly (x = 10-13, y = 3-12)

10 000

10 000

Tetrabromodiphenyl ether
C12H6Br4O
Pentabromodiphenyl ether
C12H5Br5O
Hexabromodiphenyl ether
C12H4Br6O
Heptabromodiphenyl ether
C12H3Br7O

 

 

1 000e




10 000e

Perfluorooctane sulfonic acid and its derivatives (PFOS) C8F17SO2X
(X = OH, metal salt (O-M+), halide, amide & other derivatives including polymers)


50

 

 

50

Hexabromocyclododecanef

1 000

1 000
a: Values from Annex IV of the Regulation (EC) No. 850/2004, as ammended. If these values are exceeded in a waste, then the waste must be treated to destroy the POPs. Wastes containing POPs below these levels can be treated as normal wastes.
b: Values from Annex V of the Regulation (EC) No. 850/2004, as ammended. If the concentration of POPs do not exceed these limits, under specific authorisations, certain wastes can be sent to hazardous waste landfill or stored underground without further treatment to destroy the POPs.
c: the limit is calculated as PCDD and PCDF according to toxic equivalency factors (TEFs).
d: where applicable, the calculation method laid down in European standards EN 12766-1 and EN 12766-2 shall be applied.
e: Sum of the concentrations of tetra-, penta-, hexa and hepta- bromodiphenyl ether.
f: “Hexabrocyclododecane” means hexabromocyclododecane, 1,2,5,6,9,10-hexabromocyclododecane and its main diastereomers: alpha-hexabromocyclododecane, beta-hexabromocyclododecane and gamma-hexabromocyclododecane.

An example of a common POP: PCBs

 

Richard Hooper Materials technologist Tel: +44 (0) 1793 865090