Crop protection products are applied to plants to protect them from competing weeds and harmful fungi and insects.
Residues are traces of crop protection products, that can occur in and on food, after products have been applied.
Before a pesticide can be approved for use in agriculture, its residues are measured in all types of food that you can buy in a grocery store:
- In raw food
- In foods grown in fields where pesticides have been used previously
- In foods that have been processed in any way (cooked, peeled, etc.)
- In products from animals that have eaten treated crops
Types of food
Residues are also measured in rotational crops. These are crops that have been planted in a field where a pesticide has previously been applied.
Farmers often rotate crops to preserve the quality of their soil. This means that they plant different types of crops in the same field across seasons.
Rotational crops are also called non-perennial crops, meaning that they do not grow for more than one season.
Despite not having been treated themselves, rotational crops are analyzed for their residue levels that they may have absorbed from the soil from past pesticide use.
Find substance-related study information for rotational crops in the summary documents for residue studies on our website.
Animals may be fed with crops that have been treated with a pesticide. We look for all the residues that could be in products that come from animals, like milk, meat, and eggs.
Scientists, therefore, conduct studies where animals eat feed made from treated crops. They then analyze the residue levels in their milk or meat, for example.
Find substance-related study information for animal products in the summary documents for residue studies on our website.
Many foods are not only eaten raw, but also in a processed form – such as fruit or vegetable juices, or ketchup containing tomatoes, beer made from barley, and oil made from soybeans, for example.
To assess what happens to residues in these processed foods, scientists process raw ingredients like tomatoes using typical industrial or household practices, for example frying, boiling, baking, fermenting, or pressing. The final products are then analyzed for their residue.
Find substance-related study information for processed foods in the summary documents for residue studies on our website.
These are crops that have directly been treated with a pesticide. Residues from that treatment are measured.
The test happens as follows: The products are applied to each relevant crop in line with Good Agricultural Practice (find the definition below), and this is repeated in 8 to 24 individual trials. Samples of appropriate food and feed products are taken at various intervals and are analyzed for residue levels. Afterward, the data are evaluated to better understand the residue.
Good Agricultural Practice, or GAP, is a term used to define the conditions under which a plant protection product is used. Key factors considered include the disease or pests affected by the product, the maximum allowed number of applications and their timing, the maximum product application rates per treatment, the amount of water to be used with the product, the PHI (pre-harvest interval, or time between final application and harvest), and protective measures to be taken while using the product (e.g. clothing to be worn).
When a product is registered, all the GAP information is included on the product label. Farmers using the product must comply with the instructions on the label.
But how do you know which residues to look for?
There are several ways to investigate residues in plants – for example, through metabolism studies. In these studies, biological systems (such as plants, animals, and soil) are exposed to a crop protection product. Scientists then examine the metabolites – these are any potential breakdown products that occur during metabolism. With this information, scientists can identify residues that need to be monitored.
For more information on residues testing, please click here. Substance-related study information for primary crops can be found in the summary documents for residue studies on our website.
Ready for a surprise?
Often, we don’t pay particular attention to everyday situations, even though we should give them some thought.
|Rhubard leaves are inedible as they contain toxic anthraqionones|
|Coffee contains carcinogenic substances. 100 cups could kill an adult.|
|Raw cashew nuts contain urushiol, which is a toxin. They must be cooked before eating.|
|57g of salt can kill a child.|
How safe is my food?
Your food is safe.
Crop protection products are subject to regulations, and are strictly monitored at regular intervals by government authorities.
In fact, safety standards and requirements have never been as high as they are today.
The Life Cycle of a Pesticide
Before a pesticide is submitted to an authority to be registered, it undergoes up to 10 years of testing and safety evaluation by Bayer. Once we are satisfied that it is a safe and effective product, we submit all our data to the authorities and they spend up to 2 years reviewing and making their own safety assessment before granting registration. After a product is registered, authorities continue to monitor the use of the product to ensure its safety. In many countries, authorities do a complete re-review of the product data every 10-15 years to be confident of the product’s safety, often asking for updated data. Finally, Bayer interacts with farmers and other users to ensure the product is being used safely.
Before registration, Bayer evaluates the number and type of product tests and makes risk assessments based on proposed Maximum Residue Levels (MRLs). Here, we use analytical methods for monitoring (“enforcement”).
Registration authorities evaluate all processes happening before registration. Then, if a product is deemed acceptable – and ONLY then – they publish the official MRL and use instructions like labels.
After registration, authorities monitor the residues and control the amount of crop protection used by farmers.
Farmer & Suppliers
Farmers and suppliers use crop protection products according to labels and always do bookkeeping for safety reasons.
How many – let`s say – apples would an average adult have to eat in one day to have a notable effect from typical crop protection products on his health?
Can you imagine eating 850 apples in one day? Although this is a typical example, the numbers shown are not always this high. But large safety factors are always included in dietary risk assessment to ensure that the crop protection residues that may be found in food will not pose a risk to the consumer.
So, what about food safety?
Farmers have to comply with Good Agricultural Practice (GAP), following a basic principle of using crop protection: As little as possible and only when necessary. Also, the potential residues on a harvested crop are regulated by a maximum residue level (MRL).
This makes your food safe.
NOAEL (No Observable Adverse Effect Level)
The highest does where no recognizable harmful effects are observed.
MRL (Maximum Residue Levels)
The potential residues on a harvested crop are regulated by a maximum level.
Do I have to do something?
When it comes to residues in food, there is nothing you need to do, because it is the job of professionals to keep your next meal safe.
But there are some things that are always good to consider while handling raw food to follow general food hygiene and nutrition rules.
||Wash everything and always under running water. This allows the reduction of surface impurities, such as dirt, bacteria, or surface residues.|
||Dry produce with a clean cloth towel or paper towel where possible.|
||Scrub firm fruits and vegetables, like melons and root vegetables.|
||Eat a variety of fruits and vegetables.|
- About science and producing food: Farm meets Table (Bayer)
- How we know which residues to look for (Bayer)
- Video: Is our Food safe? (English, German, French, Spanish)
- Pesticide use and food safety (European Crop Protection Association)
- Pesticide residues - What are Maximum Residue Levels (MRLs), and is my food safe? (European Crop Protection Association)
- Consumer Safety (Crop Life International)
Examples of Governmental Food Safety Monitoring Programs
- Animated video about residues in food (Crop Protection Association – UK)
- Germany (BVL) monitoring program
- USA (EPA) monitoring program
- United Kingdom (PRiF) monitoring program