Official control biotoxin monitoring (live bivalve molluscs) programme (England and Wales)

Last updated:
4 December 2017
Information relating to biotoxin testing within classified areas in England and Wales.

Weekly summary

4 December: There are no shellfish harvesting areas with restrictions in place, or which had restrictions removed this week.

Biotoxin monitoring

The maximum permitted levels of biotoxins in shellfish are as follows:

  • PSP: 800 micrograms/ kilogram
  • ASP: 20 milligrams of domoic acid/kilogram
  • Lipophilic toxins (tested by LC-MS):
    i. OA/DTXs/PTXs: 160 micrograms of Okadaic acid equivalents/kilogram
    ii. YTXs: 3.75 milligram of yessotoxin equivalent/kilogram
    iii. AZAs: 160 micrograms of azaspiracid equivalents/kilogram
  • DSP (for species not tested by LC-MS): DSP toxins must not be present

For details of any Temporary Closure Notices and/or Warning Notices please contact your Local Authority Environmental Health Officer for advice. The absence of information does not necessarily mean the area is free of biotoxins. It remains the responsibility of food business operators to ensure that their products comply with all relevant statutory requirements.

Latest results

Click here for latest biotoxin monitoring results

Previous results​

Biotoxin monitoring results 7 days ago
Biotoxin monitoring results 14 days ago
Biotoxin monitoring results 21 days ago


Phytoplankton monitoring

Phytoplankton monitoring in England and Wales is being carried out by the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) on behalf of the Food Standards Agency.

Water samples are collected from designated shellfish growing areas and analyzed, by light microscopy, for various species of phytoplankton.

Alert Level Phytoplankton concentrations have been set as per the table below and harvesters should take the necessary precautions if wanting to harvest under alert conditions.

Alert Level Phytoplankton concentration
Biotoxin Phytoplankton Alert
PSP Alexandrium
Greater than 40 cells/litre of Alexandrium
DSP Dinophysis
(Okadaic Acid)
Greater than or equal to 100 cells/litre of Dinophysis, and by historical data.
ASP Pseudo-nitzschia
(Domoic Acid)
Greater than or equal to 150,000 cells/litre of Pseudo-nitzschia, and/or historical data

Latest results

Click here for latest Phytoplankton monitoring results

Previous results

Phytoplankton monitoring results 7 days ago
Phytoplankton monitoring results 14 days ago
Phytoplankton monitoring results 21 days ago

Results from Official Controls on Pectinidae (scallops) harvested outside classified production areas. This was updated on 06/02/2017.

Scallop biotoxin results from 2017
Scallop biotoxin results from 2016
Scallop biotoxin results from 2015
Scallop biotoxin results from 2014

Further information

Liquid chromatography mass spectrometry (LC-MS) for the detection of Diarrhetic shellfish poisoning (DSP)

The Agency has approved the replacement of the MBA for detection of lipophilic toxins, including toxins responsible for Diarrhetic shellfish poisoning (DSP) with Liquid chromatography mass spectrometry (LC-MS).

The new method will be used to detect lipophilic toxins in 8 major species of commercial interest: common mussels (Mytilis edulis), common cockles (Cerastoderma edule), Pacific oyster (Crassostrea gigas), native oyster (Ostrea edulis), king scallops (Pecten maximus), Queen Scallops (Aequipecten opercularis), hard clams (Mercenaria mercenaria), and razor clams (Ensis spp.)

Results will be expressed in terms of micrograms lipophilic toxins eq/kg shellfish tissue (µg LT/kg shellfish tissue). The 'DSP Result' column will no longer report a 'negative/positive' for these 8 species (an exceedance of the statutory levels for any of the regulated lipophilic toxins, as specified in Regulation 853/2004 will lead to the closure of a production area.

High Performance Liquid Chromatography (HPLC) for the detection of paralytic shellfish poisoning (PSP) toxins

The Agency has approved the use of a chemical method, HPLC, as a quantitative assay for the testing of PSP toxins in mussels, cockles, razor clams, hard clams, minor clam species, scallops, native oysters and Pacific oysters.

The result for the PSP test continues to be reported in a similar manner to the MBA as a single figure and in terms of micrograms STX eq/kg shellfish tissue. The current maximum permitted limit of 800 micrograms STX eq/kg (80µ/100g) shellfish tissue remains unaltered.

Where the result is less than 16µg/100g the result will be noted as <RL meaning less than reporting limit. You will be aware that alert level is between 40-79µg/100g and there is no change to this practice.


Should you have any queries about the monitoring programme please contact:

Rebecca Watts
tel: 020 7276 8046

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