Research and analysis

Quarter 3 2023 report on the pesticide residues monitoring programme: issues arising in this report, follow-up from previous reports and plans for the quarter 4 report

Updated 25 September 2024

Issues arising in this report

Chlorate

We have been testing a limited number of foods for chlorate since 2016. The pesticide sodium chlorate is a residual broad action weed killer that is not authorised for use in the EU or UK. However, we are confident that the residues we are detecting come from use of chlorine-based disinfectants used to maintain microbiological safety (control microorganisms that cause food poisoning). Because these residues are unavoidable, and important for the maintaining of microbiological control vital for food safety, we are not treating these results as breaches of the maximum residue level (MRL). We are not advising that food companies change their existing practices as a result of our findings, but they should be aware about the ongoing discussion in this area.

We are only part of the work going on across government and beyond to consider what to do about chlorate residues in food and water.

How chlorate MRLs take account of use of biocides

The footnote included in the chlorate MRLs takes into account chlorate residues incurred during the processing of food (from treated water or processing aids, such as biocides). The footnote exceptionally specifies that for considering compliance with chlorate MRLs, simple types of processing, such as packing, washing, chopping and freezing can be taken into account. Chlorate in irrigation water is taken into account in the MRLs as set and no further adjustment can be considered.

The responsibility for providing evidence showing that residues from processing can be taken into account, lies with the food business operator, and so we will be interested to see such evidence where appropriate. HSE will decide whether the footnote can be applied and if so this will be reflected in our reports.

Read more information on the Chilled Food Association’s website, produced by the Food and Biocides Industry Group.

Infant food

Infant food MRLs are set under separate legislation managed by UK health departments. The footnote that applies to other foods cannot be used for infant foods, although residues occur for the same reasons. UK health departments are working with HSE and the Food Standards Agency (FSA) to resolve this.

Sanitisers

The presence of low-level residues of chlorate in food results from measures taken by the food and water industries to protect food safety by reducing microbiological contamination of food and drink (including drinking water, which is a significant source of chlorate in food). Chlorate itself is not used as a disinfectant, but chlorine-based sanitisers contain small amounts of chlorate. The Food Standards Agency has worked with industry who promote best practice and guidance for use of sanitisers.

Drinking water

In national legislation throughout the UK it is already a requirement to keep disinfection by-products as low as possible. This is usually achieved through management of disinfectant dosing and storage.

Microbiological safety of food

The HSE is working with the Advisory Committee on the Microbiological Safety of Food to understand how changes to pesticide MRLs affect biocide use, microbiological food safety, and any change to the overall risk to consumers taking into account both chemical and microbiological safety.

Dietary intakes

Since 2018 the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) has been considering chlorate as part of its on-going work looking at the chemicals in the diet of infants and young children (up to 5 years). The European Food Safety Authority’s 2015 opinion on chlorate^{[footnote 1]} establishes appropriate health-based guidance values for chlorate exposure to protect against acute and chronic risks to health.

Fosetyl-Al (sum)

The full residue definition is ‘fosetyl-Al (sum of fosetyl, phosphonic acid and their salts, expressed as fosetyl)’. Throughout this report that definition is reflected as fosetyl (sum) All the residues reported as fosetyl (sum) in this report were detected as phosphonic acid.

Fosetyl-Al breaks down to phosphonic acid, but phosphoric acid can also be a residue left by use of pesticides containing disodium phosphonate or potassium phosphonates. Additionally, products sold as fertilizers also can contain or break down to phosphonic acid. And finally, phosphonic acid also occurs naturally in the environment. The presence of phosphonic acid does not necessarily mean that a pesticide was used. Those producing food need to be aware that the use of products that contain phosphonic acid or break down to phosphonic acid may lead to produce which breaches the MRL.

DDT

The use of DDT is banned of heavily restricted in many countries. It is not allowed for use on food crops anymore, but it is still used in some countries outside the EU as a public health insecticide. Residues of DDT take a long time to break down in the environment and can accumulate in fatty tissue which is a major reason that it has been banned in the EU and many other countries.

Due to the bans and restrictions on use the levels in food have decreased substantially since the 1960s and 1970s. Even so, because it takes a long time to break down we do expect, and do see, occasional DDT residues in our monitoring results. Overall, the incidence and the size of residues have fallen steadily over time, which is what we would expect. In recent years none of our findings were unusual, unexpected or of concern. We can tell from the chemical form that we detect whether the residues we have found are from historic use (which is what we usually find). Historic use is indicated by the detection of DDE which is a break down product of DDT. We explain this every time we publish DDT results to try to make it as clear as we can that the results show food producers are not using DDT today. However, there are occasional media stories about DDT and various links and associations, which do not make this distinction.

The residues we find nowadays are at levels that would not be expected to have any effect on health, either in the short term or in the long term, when checked against today’s understanding of the effect of DDT on health. As a committee, we take care to ensure we look thoroughly at this, and the Food Standards Agency is also actively involved in our considerations.

Processing factors

As the surveillance programme monitors residues in all types of food, from raw commodities (for example, potatoes) to processed (for example, wine), dried (for example, dried fruit) and composite foods (for example, fruit bread), consumer risk assessments are specifically tailored to address processed and mixed food products. MRLs are generally set for raw commodities, although when MRLs are established the assessment of dietary intakes takes into account the potential for residues to remain in processed foods produced from the raw agricultural commodities. MRLs have been set for processed infant foods, and in future may be extended to other processed food products.

MRLs apply to all traded foods, including foods used as ingredients. The law specifies the level to apply to foods as they are traded. For almost all foods that means their raw, unprocessed form. But MRLs also apply to prepared and processed foods in which case the effect of processing needs to be taken into account.

In nearly all cases the MRL is set for the food in its raw, unprocessed form (the form of each food to which MRLs apply is listed in Annex I of Regulation 396/2005). These MRLs can be applied to processed foods using appropriate processing factors. Processing factors take account of the effect of processing on the food as traded. Different forms of processing may remove, concentrate, or dilute residues, and the effect may vary depending on the food and the pesticide concerned. Multiplying the processing factor by the original MRL gives a calculated MRL that can indicate the food was made with an ingredient or ingredients which had residues over the original MRL.

Calculating the MRLs for processed goods is dependent on the information available. HSE will contact the supplier if residues exceed the calculated MRL to give them an opportunity to provide relevant information to support the calculation.

Processing factors for bread were taken from a published compilation of factors.

HSE use the general principle that if no specific processing factor is available, a default factor of 1 may be applied. Further information can be found at:

• the European database of processing factors for pesticide residues in food Version 2
• the Official Journal of the European Union - the commission implementing EU regulation 2018/555

Processing factors and MRLs used for bread

Food type	Pesticide	Processing factor	MRL for unprocessed grain (mg/kg)	Bread MRL (mg/kg)
Bread (speciality bread: bagels)	cypermethrin (sum)	0.48	2	0.96
Bread (speciality bread: croissants)	cypermethrin (sum)	0.48	2	0.96
Bread (speciality bread: waffles)	cypermethrin (sum)	0.48	2	0.96
Bread (ordinary bread: other)	glyphosate	0.12	10	1.2
Bread (ordinary bread: white)	glyphosate	0.12	10	1.2
Bread (ordinary bread: wholemeal)	glyphosate	0.12	10	1.2
Bread (ordinary bread: bagels)	glyphosate	0.12	10	1.2
Bread (speciality bread: croissants)	glyphosate	0.12	10	1.2
Bread (speciality bread: muffins)	glyphosate	0.12	10	1.2
Bread (ordinary bread: other)	chlormequat	0.71	7	4.97
Bread (ordinary bread: white)	chlormequat	0.71	7	4.97
Bread (ordinary bread: wholemeal)	chlormequat	0.71	7	4.97
Bread (ordinary bread: bagels)	chlormequat	0.71	7	4.97
Bread (speciality bread: brioche)	chlormequat	0.71	7	4.97
Bread (speciality bread: croissants)	chlormequat	0.71	7	4.97
Bread (speciality bread: crumpets)	chlormequat	0.71	7	4.97
Bread (speciality bread: muffins)	chlormequat	0.71	7	4.97
Bread (speciality bread: pancakes)	chlormequat	0.71	7	4.97
Bread (speciality bread: pikelets)	chlormequat	0.71	7	4.97
Bread (speciality bread: scones)	chlormequat	0.71	7	4.97
Bread (speciality bread: waffles)	chlormequat	0.71	7	4.97

An asterisk (*) shows the limit of determination (LOD) MRL

Follow-up from previous reports  

Quarter 4 2021 - mushrooms (NI) deltamethrin 

Sample: 0667/2021 

Following consideration by DAERA no further contributing information could be found. HSE had concluded that this finding was not a safety concern. Therefore the case has been closed.

Quarter 4 2022 - Apples (NI) pirimicarb 

Sample: 5212/2022 

The sample was grown in Northern Ireland. The Department of Agriculture, Environment and Rural Affairs (DAERA) of the Northern Ireland Government had insufficient information to identify the precise grower responsible in order to take direct action.

However they noted that use of pirimicarb on Bramley Apples is also identified in the 2022 Pesticide Usage Survey for Northern Ireland Top Fruit which reports an estimated area of 65 hectares of Bramley apples treated with a total of 9 kg of pirimicarb. Prior to 2022, that last recorded use was in the 2016 Pesticide Usage Survey for Northern Ireland Top Fruit when there was an authorised use of a PPP called Aphox (MAPP 10515) which included aphid control on apples.

DAERA have therefore advised their Agri-food Inspectors and their Agricultural Advisors at the College of Agriculture, Food and Rural Enterprise (CAFRE) of the issue. They have also informed the relevant Ulster Farmers Union (UFU) Policy Advisor to seek their support in providing re-education of the use of pirimicarb with the relevant grower groups and committees.

In our quarter 4 report

Samples collected in Great Britain

In quarter 4 of 2023 we will look at results from samples collected in Great Britain for:

• beans (dried)
• beans with pods
• bread (morning bakery)
• bread (ordinary)
• carrot
• cauliflower
• crisps (potato based)
• fish (oily)
• grapes
• kiwi fruit
• lemons
• liver
• milk
• onions
• orange juice
• oranges
• pears
• peas without pods
• pineapples
• potatoes
• poultry meat
• rice
• rye flour
• snacks (speciality)
• soft citrus

Samples collected in Northern Ireland – provisional

In quarter 4 of 2023 we will look at results from samples collected in Northern Ireland for:

• beans (dried)
• beans with pods
• bread (morning bakery)
• bread (ordinary)
• brussel sprouts
• carrot
• cauliflower
• fish (oily)
• grapes
• infant formula
• kiwi fruit
• lemons
• liver (bovine)
• milk
• onions
• oranges
• pears
• peas with edible beanspods
• pineapples
• potatoes
• poultry meat
• rice
• rye flour
• soft citrus
• spring onions

This document is part 4 of 4 of the Quarter 3 2023 report.

Previous: Quarter 3 2023 report on the pesticide residues monitoring programme: findings by food in Northern Ireland and risk assessments.

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1. EFSA Journal 2015;13(6):4135 [103 pp.] ↩