Unit Toxicology of Active Substances and their Metabolite

The primary responsibility of the unit is the toxicological assessment of active substances used in plant protection products or biocides. The degradation products (metabolites) and impurities in the active substances are also considered.

Toxicological assessments are completed as a statutory task according to the laws on pesticides and chemicals within the context of the regulatory approval, licensing and assessment procedures for pesticides. This is carried out in line with the EU Regulations on plant protection products and biocidal products, as well as within the scope of stipulation and monitoring of maximum residue concentrations.

The active substances in pesticides and their metabolites must be regularly assessed with regard to the following main aspects:

• Toxicokinetics/metabolism;
• Acute toxicity, skin and eye irritation, sensitisation;
• Repeated dose toxicity;
• Chronic toxicity/carcinogenicity;
• Genotoxicity;
• Reproduction and development toxicity;
• Neurotoxicity, immunotoxicity and endocrine disrupting properties;
• Observations in human beings.

As a result of the assessment, health-based reference values are derived for the active substances, i.e. maximum intake levels which, if complied with, are not expected to have an adverse effect on the health of exposed persons:

• ADI (Acceptable Daily Intake): limit value for the long-term exposure of the consumer through food
• ARfD (Acute Reference Dose): limit value for the acute exposure of the consumer through food
• (A)AOEL ((Acute)Acceptable Operator Exposure Level) or AEL (Acceptable Exposure Level): limit values for the exposure of the user and uninvolved third parties

Furthermore, the classification and labelling of the active substance is proposed on the basis of its toxicological properties.

Metabolites of these active substances are assessed in terms of their toxicological relevance in the soil, in the groundwater and in residues of foods of animal and plant origin. If necessary, reference values such as ADI and ARfD are also derived for these degradation products to be able to assess any risks from ingestion with food.

Other key tasks of the unit are to provide scientific advice on questions related to the toxicological assessment and participation in the drafting and further development of testing methods, testing and assessment strategies, and technical guidance documents of the EU or the OECD, in which the procedures for regulatory risk assessment are regulated.

Furthermore, the unit also conducts research and development to support regulatory procedures, particularly in the areas of “combination effects” and “in silico”, i.e. computer-assisted methods, such as (Q)SAR. One of the unit’s additional tasks, which is also reflected in its research activities, is the assessment of the toxicological effects of pesticides and biocides on our pets and livestock.