MRLs and import tolerances

A maximum residue level (MRL) is the maximum concentration of a pesticide residue in or on food or feed that is legally tolerated when a plant protection product (PPP) is applied correctly (following good agricultural practice).

GB MRLs apply to produce both treated in Great Britain (England, Scotland and Wales) and imported into Great Britain. There are different rules for MRLs in Northern Ireland.

An import tolerance is a specific MRL set on imported food or feed to meet the needs of international trade.

More about GB MRLs

There is separate guidance about:

GB MRL register

MRLs are regulated in GB under Regulation (EC) No 396/2005.

MRLs apply to most food commodities, except fish and produce grown exclusively for animal feed.

MRLs are not set specifically for processed commodities, instead the MRLs for the raw agricultural commodities apply, considering changes in the residue levels caused by processing. Part 1 of the register lists these commodities.

Parts 2 and 3 of the register list the GB MRLs currently in force.

Part 4 of the register lists active substances exempt from MRLs. Active substances may have been included in Part 4 of the register based on a specific risk assessment. Therefore, their inclusion does not necessarily mean a residues and dietary exposure assessment is not required. Applications for new authorisations may need to include additional information. This ensures the conditions for MRL exemption are still applicable and that there are no concerns for consumers and/or MRLs.

Part 5 of the register lists active substances for which all MRLs are set at the appropriate limit of quantification. For example, this may be following a non-approval decision for an active substance.

Part 6 of the register has not yet been established. It will cover specific concentration or dilution factors for certain processed and/or composite products.

Part 7 of the register lists active substances that can temporarily exceed the MRLs when used as a fumigant in transit.

For active substances with no MRLs set, a default MRL of 0.01 mg/kg applies.

Setting MRLs

MRLs are set at the lowest level consistent with when the plant protection product is applied correctly (following good agricultural practice). MRLs are established using the OECD MRL calculator.

In a limited number of cases temporary MRLs may be set based on monitoring data. For example, this may be to cover environmental contamination or cross contamination. The use of the OECD calculator may not be appropriate in such cases to establish the MRL.

Consumer safety

Risk assessments support MRLs which protect all consumers. This includes vulnerable groups such as babies and children. HSE evaluates data on residues in treated commodities and the toxicology of the pesticide. Find out more about the residues data requirements and how consumer risk assessments are conducted.

MRLs are set below the levels which would pose consumer safety concerns.

Who has to comply with MRLs

Businesses must comply with MRLs in force if involved in the following activities associated with food or feed:

This includes importing food into Great Britain.

MRL monitoring and enforcement

Compliance with MRLs is monitored through a programme of official testing for residues in food and drink.

The PRiF (Expert Committee on Pesticide Residues in Food) oversees the monitoring programme. A risk-based approach is applied to the targeting of monitoring activity (focusing on foodstuffs most likely to contain residues or of specific interest).

HSE may take enforcement action if any evidence suggests pesticides are not being applied correctly (following good agricultural practice), or if serious breaches of MRLs occur.

UK Internal Market Act

The approach to monitoring and enforcement will also be subject to the provisions in the UK Internal Market Act on mutual recognition, as mutual recognition applies to MRLs. The Act is on

Food businesses

If your business trades in food produce you should be aware that GB MRLs and EU MRLs (which apply in Northern Ireland) may start to diverge over time. You should consider the implications in your target market.

Updated 2021-08-06