Maximum concentration levels for foreign substances in plant protection products
Summary
Within the framework of the authorisation procedure, all substances that are added to the plant protection product must be indicated by name: active substances together with impurities, co-formulants, safeners and synergists. The intentional addition of a foreign substance to a plant protection product is not allowed. Plant protection products containing foreign substances in concentrations above 0.1 % cannot be marketed.
Introduction
Plant protection products are checked by different authorities with regard to their composition. For this reason, as part of a plant protection product market inspection, the authorities of the Federal Länder take regular samples from the market, during the import control and also during their application, for example when damage had occurred. These samples are examined in the laboratory for formulation chemistry at the Federal Office of Consumer Protection and Food Safety (BVL). The aim is to control the marketability of the plant protection products, strengtheners and adjuvants concerned. Where it emerges that the products cannot be marketed, the Federal Länder have the power to impose sanctions against the distributor. In this case, the BVL can establish consequences for the authorisation of plant protection products, the approval of products intended for parallel trade or for the listing of plant strengtheners and adjuvants.
But also commercial laboratories and authorisation holders' laboratories examine the composition of plant protection products and compile expert opinions on marketability.
Particularly active substances and co-formulants which were evaluated in the authorisation procedure and defined with the authorisation certificate are examined in these checks. Impurities specified in the EU-evaluation program for active substances also belong to the possible scope of examination. Sometimes substances are detected which do not belong to the active substances stated by the applicants, like co-formulants or impurities, the so called foreign substances. These foreign substances have not been evaluated and are not covered by authorisation or listing. Moreover, technical progress has made it possible to analytically detect very low doses of substances in a wide variety of matrices. Therefore, it is important to define the concentration of foreign substances allowed in plant protection products.
The intentional addition of a foreign substance to a plant protection product is not allowed. However, if a foreign substance constitutes a contamination, the present legal framework contains no explicit rules as to the admissible concentration. The BVL assumes that the maximum level for foreign substances has to be set at 0.1 % (in relation to the product). This value is justified on the grounds that it is also used by the legislator as a basis in numerous other contexts (see statements relating to the legal requirements). In march 2019, this value was incorporated in the EU reference document „Reference document illustrating best practices on analytical strategies and interpretation of results for the formulation analysis of plant protection products obtained during official market control“ as the concentration limit. These limits were established in the EU-Commission working group „Working Group on Plant Protection Product Formulation Analysis “.
When it is unclear, whether the detected foreign substance is attributable to the active substance or the product or whether it has been added intentionally, the BVL will then assume that the product is contaminated. This is why the BVL considers plant protection products containing foreign substances in concentrations above 0.1 % as non-marketable.
When assessing analytical results, the uncertainty of measurements due to analysis must be taken into account. The BVL generally takes a tolerance range of 15 % into account for homogeneous formulations and 25 % for heterogeneous formulations with respect to impurities and foreign substances, according to the requirements from the EU reference document. It is assigned to the measured values and will be taken into account when interpreting the measuring results.
Legal stipulations
Evaluation of the Active Substance
According to Part A, Section 1.10. of the annex of Regulation (EU) No 283/2013, all components exceeding 0.1 % must be stated in the EU-evaluation of active substances. Substances which are more toxic or ecotoxic than the active substance are considered relevant impurities. Such substances must be declared even if they are below 0.1 %. When active substances are approved, relevant impurities are defined for some active substances and maximum limits are set for these. The maximum limits of active substances are published in the Regulation (EU) No 540/2011 and can be found in the EU Pesticides Database of the European Commission.
They apply to the technical active substance. They must also be observed for plant protection products in relation to active substance content.
Authorisation procedure
When applying for the authorisation of a plant protection product, components (active substances, safeners, synergists and co-formulants) that have been intentionally added must be declared, regardless of the amount. This derives from part A, section 1.4.1. of the annex of Regulation (EU) No 284/2013.
Co-formulants are characterised by a trade name and often consist of several components. These must be declared if they are present in a co-formulant with more than 0.1 %. Moreover, components under 0.1 % must also be declared if
- the components are very toxic, ecotoxic or phytotoxic (e.g. sulfonylurea),
- it is possible for maximum residue levels to be exceeded,
- the content of the actual active substance in the formulation is low and therefore a significant increase in efficacy can also be expected for contents < 0.1 %. For example, active substance contents of < 0.1 % are not unusual in plant protection products for amateur gardening.
Other legal stipulations
The order on the use of plant protection products (Plant Protection Use Ordinance-PflSchAnwV) contains prohibitions and restrictions for plant protection products containing certain substances. According to Article 6, negligible impurities due to technical reasons and manufacturing remain unconsidered as long as the protection of human health or preventing danger in particular for human and animal health and for the natural balance is not impaired. This regulation could possibly be interpreted to mean that evidence must first be provided of a risk to human and animal health and for the natural balance before the contamination of a plant protection product containing foreign substances can be rejected. However, taking into account the aims of the Plant Protection Use Ordinance (prohibition/restriction of particularly critical active substances), Article 6 is to be interpreted restrictively. A content above 0.1 % cannot be seen as negligible.
The Regulation (EC) No 396/2005 and the order on maximum residue levels establish the maximum permitted levels for plant protection active substances in food of animal origin or plant origin. These stipulations also apply to foreign substances. If they are present in a plant protection product, it must be ensured that maximum limits are not exceeded in food of animal origin or plant origin.
Furthermore, the Hazardous Substances Ordinance contains numerous manufacturing and use bans for substances and mixtures. These stipulations also apply to plant protection products. Maximum limits are stated for some substances, which are below 0.1 % in many cases.
The legal requirements with regard to plant protection products suggest that the maximum limit of 0.1 % is technically acceptable as a permissible foreign substance level.