Chemical contaminant monitoring data 2015 - England and Wales

Last updated:
8 December 2016
Information relating to chemical contaminant testing within classified areas in England and Wales.

Live bivalve molluscs feed by filtering plankton from the surrounding water that washes through their habitat. This feeding mechanism can lead to the bio-accumulation of environmental pollutants. 


Regulation (EC) No. 854/2004 requires the FSA, as the Central Competent Authority, to monitor classified shellfish production areas for a range of parameters, including chemical contaminants. 

Classified shellfish production areas across the UK are periodically monitored, as part of the FSA’s official control monitoring programmes, to ensure levels of chemical contamination in live bivalve molluscs do not exceed the regulatory limits laid down in Commission Regulation (EC) No. 1881/2006 as amended.

Classification and production of relaying areas

Across the UK, shellfish samples are collected by authorised sampling officers and delivered to official control laboratories, where chemical testing is carried out to detect levels of:

  • Heavy metals
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Dioxins
  • Poly-chlorinated biphenyls (PCBs).

Testing is carried out in accordance with the criteria set out in Commission Regulation (EC) No. 333/2007 as amended (metals, PAHs) or Commission Regulation (EU) No. 589/2014 as amended (dioxins and PCBs).

Regulatory limits
Heavy Metals LBMs (mg/kg)
Lead (Pb)


Cadmium (Cd) 1
Mercury (Hg) 0.5
Polycyclic aromatic hydrocarbons (PAHs): LBMs (µg/kg)
Benzo(a)pyrene 5.0
Sum of EFSA 4 LBMs (µg/kg)


SUM 30
Dioxin and Dioxin like PCBs: LBMs(pg/g=ng/kg)
Sum of dioxins 3.5 pg/g wet weight
Sum of dioxins and dioxin-like PCBs 6.5 pg/g wet weight
Sum of PCB28, PCB52, PCB101, PCB138, PCB153 and PCB180 75 ng/g wet weight

2016/17 Programme

Following a review of the current classified harvesting areas only one site (Beaulieu River) has been identified as requiring monitoring in the 2016/2017 programme. Sampling will be completed by the end of November 2016 and results will be published as soon as they are available.