Radionuclides — Seafish


When a situation arises that leads to levels of radioactivity in food that are higher than natural levels, there is legislation to limit exposure.

Natural levels of radioactivity in food are extremely low and there is normally no specific legislation prescribing limits for radionuclides in food. However, in the case of a nuclear accident or radiological emergency, retained EU Regulation 2016/52 becomes active. This requires the UK authorities to apply maximum permitted levels of radionuclides in food.

The maximum permitted levels are set no higher than the levels below:

Nuclides Maximum permitted level (Bq/kg)

Isotopes of strontium, notably Sr-90


Isotopes of iodine, notably I-131


Alpha-emitting isotopes of plutonium and transplutonium elements, notably Pu-239 and Am-241


All other nuclides of half-life greater than 10 days, notably Cs-134 and Cs-137


The UK authorities have an obligation to keep the new maximum radionuclide levels under review and to amend them as appropriate.

In addition to retained EU Regulation 2016/52, there are 2 other Regulations that refer to radioactive contamination of foods:

  • Retained EU Regulation 2219/89 lays down the conditions for exporting food and feed after a nuclear accident or radiological emergency. Food and feed with levels of radioactive contamination that exceeds permitted levels may not be exported.
  • Retained EU Regulation 733/2008 applies to agricultural products originating in third countries that are affected by the Chernobyl accident.

 Special measures following Fukushima

Following the Fukushima incident of 2011, the EU introduced enhanced import controls on food originating from affected areas in Japan. The UK carried out a review of the enhanced controls in 2022. The conclusion was that the enhanced measures are no longer necessary, and that general food law requirements are sufficient to guarantee food safety.

Monitoring Radioactivity in the UK

Major producers of radioactive waste in the UK are required to monitor the environment around their premises. The Environment Agency, the Food Standards Agency, the Northern Ireland Environment Agency and the Scottish Environment Protection Agency work together on monitoring programmes to measure radioactivity in the environment and in food.

Their results are brought together annually in the Radioactivity in Food and the Environment (RIFE) report. The report lays out the risk to public health of any radioactivity that is detected.

More information about radioactivity in food can be found in this Food Standards Agency page; the latest RIFE report is available here.

How safe are the limits?

The levels set in retained EU Regulation 2016/52 are based on the following assumption.

A person consuming a diet containing 10% of food contaminated at the maximum level will, over 1 year, receive a dose of ionising radiation of 1 millisievert (mSv). 1 mSv corresponds to the acceptable annual dose limit for a human being; the potential dose of 1 mSv from the diet will be in addition to any other ionising radiation, natural or otherwise, received by that person.

Notes on the units used to describe radioactivity

The limits are set in Bq/kg (becquerel per kilogram). A becquerel is an amount of radiation emitted equal to the number of disintegrations per second the radionuclide undergoes.

Roughly speaking, the more becquerels, the more the harmful radiation, but this may be misleading, because there are different types of radiation (alpha, beta, gamma and neutron radiation), each with its own adverse health effect. In addition, the health effect depends on parameters such as the food, its consumption and the age of the consumer.

1 millisievert (1 mSv) corresponds to the acceptable annual dose limit for a human being. The sievert is a derived unit that describes a dose of radiation in terms of the biological effect that it has on the human body. The definition of the sievert depends on the relationship between the radiation and the effect on the human body, and is determined by the International Commission on Radiological Protection.