Are supermarkets monitoring and reducing pesticide residues in food?

Pesticides used in agriculture can appear as residues in our food. Fruit and vegetables tend to contain the most pesticide residues (both in terms of variety and amounts) but they can also be found in many other types of food including grains such as wheat and rice, meat, dairy, wine and honey.

The residues detected on a food item will depend on which pesticides have been used and how persistent they are or, put another way, how long they take to decompose. Many pesticide residues are contained within the entire piece of produce rather than just on the surface. As a result, peeling fruit and vegetables before eating is often not enough to prevent exposure to pesticides. In addition, residue safety levels are set for just one pesticide at a time but items on supermarket shelves can contain traces of as many as 17 different pesticides.

All UK supermarkets conduct their own residue testing programmes. Their tests are largely aimed at identifying produce containing residues above the standard set by government which is known as the ‘Maximum Residue Level’ (MRL). When an exceedance of an MRL is identified, a supermarket will often work with the farmer to reduce residues and ensure the problem doesn’t happen again. Sometimes supermarkets will identify a residue problem with a particular food item from a specific country – for example, grapes from South Africa – and put in place an action plan for tackling it.

Almost all supermarkets have an action plan in place if they identify a residue which exceeds the legal limit, but the level to which it needs to exceed will vary depending on the supermarket. For example, some supermarkets carry out stringent investigations as soon as a residue goes beyond 50 percent of the legal limit, while for others its 80 or 100 percent.

Currently, only two supermarkets (M&S and Co-op) publish the results of their residue testing programmes in sufficient detail to enable customers to find out what residues appear in which produce.  While this is progress since 2019 when not a single supermarket published this information, the other eight supermarkets (including Asda and Morrisons which do at least publish broad overviews of their results) should follow suit to enable their customers to make more informed shopping decisions. Given the huge uncertainty around how exposure to multiple pesticides through food residues impacts upon human health, we should be taking a precautionary approach and reduce pesticide use whenever possible. Residues continue to be highly unpopular with UK shoppers who tend not to want traces of chemicals in their food.

Ask your supermarket to take action on pesticides

Topics we reviewed

Are supermarkets doing enough to support suppliers to reduce their use of pesticides
Are supermarkets doing enough to reduce pesticide residues on food?
Are supermarkets doing enough to reduce hazardous pesticides in the supply chains?
Are supermarkets doing enough to engage customers on pesticide issues?
Are supermarkets doing enough to protect bees and pollinators from pesticides?
Are supermarkets doing enough to be transparent about the pesticides in their supply chains?
Why are supermarkets selling pesticides products?
Are supermarkets doing enough to increase the amount of organic produce on sale?