Produits Phytopharmaceutiques

Assessment of active substances used in the composition of plant protection products

Procedures and agencies involved

Plant protection products are preparations consisting of one or more active substances, which are responsible for the properties of the plant protection product, and of substances called co-formulants, which give the product a form suitable for its application. The assessment of active substances is regulated and carried out otn the European level. Find out how substances are approved and who is involved in this process.

Assessing the active substances in plant protection products before they can be placed on the market is coordinated at the European level by the European Food Safety Authority (EFSA), which relies on research conducted by experts belonging to the various Member States.

This assessment serves to characterise the intrinsic properties of each substance and to identify possible hazards to humans and to the environment.

It is also used to define the toxicity reference values required for risk assessment: 

  • acceptable daily intake (ADI);
  • acute reference dose (ARfD) for consumers;
  • acceptable operator exposure level (AOEL) for the person applying the product and other workers.

Finally, it enables an assessment of the risks for humans and for the environment related to using the active substance, for one or more representative uses. 

Defining maximum residue limits in food is also assessed at the European level and is coordinated by EFSA.

The Procedure

When a manufacturer wishes to get a new substance approved under Regulation (EC) 1107/2009, it compiles the application and sends it to the Member State of their choice. This State examines the application and becomes the rapporteur for that dossier. It then sends its assessment report to EFSA.

EFSA then sends this report to the other Member States, collects their comments, and organises debates between the experts of these States. This process then enables EFSA to publish an informed opinion, which is transmitted to the European Commission.

For France, ANSES fulfils this role of evaluator or re-reader through its Regulated Products Assessment Department.

The final report is discussed at the EU level by the Standing Committee on the Food Chain and Animal Health (Plant Protection Products section) of the European Commission (DG SANCO). This committee includes representatives of the competent authorities of the Member States, who rule on the approval of active substances according to European regulations on the basis of EFSA’s findings.

Only approved substances can be used in plant protection formulations.


Evaluating an active substance involves characterising the hazards related to its intrinsic properties and  conducting a risk assessment, taking into account the intended uses. It involves:

  • determining physical and chemical properties (flammability, explosiveness, solubility in water and in solvents, vapour pressure, etc.) and assessing the validity of analytical methods for the active substance and its residues (in formulated products, in plants, foodstuffs of animal origin, water, air, or soil);
  • evaluating toxicity to humans: metabolism and kinetics, acute toxicity, local tolerance including allergic risk, sub-acute and chronic toxicity in several species of mammals, toxicity vis-à-vis reproductive functions (teratogenicity and multi-generational studies), mutagenic and carcinogenic potential for several species;
  • proposing toxicity reference values ​​needed for assessing the risk to humans: acceptable daily intake (ADI), the acute reference dose (ARfD) for consumers, and acceptable operator exposure dose (AOEL) for the person applying the product, workers and bystanders;
  • assessing residues in plants, in processed products and in foodstuffs of animal origin. This part of the dossier assesses qualitative data (metabolism in plants and animals, hydrolysis studies) which are used to define the acceptable levels of residue(s) in foodstuffs of plant or animal origin. This section also includes quantitative studies that provide an estimate of the expected residue levels in plant, animal or processed products when the substance is used in accordance with best agricultural practices. These studies thus help to define the maximum residue limits (MRLs) for each type of foodstuff;
  • assessing risk for humans resulting from representative uses. This assessment compares expected exposures, which have been estimated from models, with the chosen toxicity reference values. For the consumer, this assessment takes into account the expected residue levels and the daily consumption of the food by different populations. It thus compares this exposure to the ADI and the ARfD to assess, respectively, the long-term and acute risk. Similarly, the risk to the person applying the product, the worker who deals with the treated crop, passers-by, and local residents are also assessed by comparing the expected exposures to the AOEL;
  • evaluating the fate of the substance and its behaviour in the environment (the study of how it degrades in water, air, soil, in light and in darkness); the possibility of migration of either the substance or its metabolites into surface or groundwater and air; finally, evaluating its persistence in the environment by means of laboratory analyses and field studies. This evaluation then allows us to estimate the level of contamination of various environments (soil, water, air) by the active substance and its metabolites;
  • assessing toxicity to flora and fauna, including toxicity to birds, aquatic organisms (fish, crustaceans, algae, benthic organisms, higher plants), terrestrial mammals, terrestrial arthropods, insects, especially bees, earthworms and other soil macro-organisms, soil bacteria and terrestrial plants;
  • assessing risks to the Environment, which enables an assessment of the risks to non-target organisms associated with representative uses of the active substance. This assessment is based on the contamination of different environments and the toxicity of the active substance and its metabolites.

This evaluation also includes classification proposals for human health, the environment and the physico-chemical properties relating to the hazards of the active substance. This classification will determine the labelling of products containing this substance.

The review of the classification of substances is coordinated by ECHA (European Chemicals Agency) under the framework of Regulation (EC) 1272/2008.

Products containing active substances are assessed on the national level prior to marketing. ANSES issues, withdraws and amends authorisations based on the findings of risk assessments.