POP code

PCP Pentachlorophenol

Pentachlorophenol is a persistent organic pollutant (POP) on DEFRA's reference list. Waste containing a regulated POP above the concentration limits in Annex IV of the POPs Regulation is classified as hazardous under HP POP, and the component must be declared — with its concentration — when the movement is filed.

PCP waste is most often timber. Pentachlorophenol was used for decades as a wood preservative and biocide — fence posts, sleepers, telegraph poles, structural timber — so it turns up in demolition and site-clearance loads long after its use was restricted, in wood that looks like ordinary waste wood.

That matters because a POP above its limit does not just make a load hazardous, it changes what can be done with it: waste containing a persistent organic pollutant above the concentration limit set for it in Annex IV of the POPs Regulation has to be treated so the POP content is destroyed or irreversibly transformed, which rules out the wood-chip and panel-board recycling routes ordinary waste wood takes. Mixing is not a way round that — diluting POP waste to bring it under a limit is not a route to compliance — so timber you suspect is worth assessing before it goes in with anything else.

On a movement, the POPs present are declared as components with their concentrations, using the code rather than the chemical name. The waste itself still needs its own EWC code, and where the concentration exceeds the Annex IV limit the hazard is recorded under HP POP.

Code

PCP

Hazard classification

HP POP, where the concentration exceeds the Annex IV limit

Concentration reported in

mg/kg

Sourced from DEFRA’s digital waste tracking reference data, last checked 25 July 2026.