Application safety of plant protection products

BfR tests and assesses whether the health of all persons who come into contact with the product during its application can be ensured when the product is used correctly and in line with its intended purpose. This is a requirement for the authorisation of plant protection products.

The following groups of people are taken into consideration:

• Users who may be exposed to plant protection products or their components through the skin or through inhalation during the application process, as well as workers who carry out follow-up work on the treated area.
• People who live or work in the vicinity of the treated areas (residents) or people who happen to be in the area during application (bystanders, e.g. people walking by), who can be exposed to plant protection products or their components through the skin, through inhalation or, in the case of small children, through the mouth.

Exposure assessment for users, workers, residents and bystanders

In the course of the evaluation of application safety, BfR determines the maximum expected intake for each of these potential routes of exposure before a plant protection product is authorised. For this evaluation, the proposed conditions of use serve as a basis.

Separate exposure assessments are carried out for the aforementioned groups of people.

BfR determines the exposure of users (generally farmers, but can also include horticultural workers or amateur users in home and allotment gardens) using model calculations. These models are based on measurement values for each type of application. Kinetic considerations (for instance, how much of an active substance can be absorbed through the skin) are also included in the exposure assessment, as are potential protective measures which may reduce exposure (e.g. protective gloves).

Exposure during follow-up work is calculated not only for farmers, but also for horticultural workers, workers in processing plants or for non-professional applications in home and allotment gardens.

When evaluating residents and bystanders, BfR not only accounts for adults, but also for small children, as they often put their fingers in their mouths or swallow certain items (e.g. sand, parts of plants).

Further useful information and resources on the assessment can be found under "Exposure assessment".

Models as a basis for exposure assessment

For the exposure assessment, BfR initially uses models with very conservative assumptions.

The guidelines for calculating the exposure of users, workers, bystanders and residents are harmonized in the EU and have been published by the European Food Safety Authority (EFSA).

If the determined exposure levels do not exceed the relevant limit values, further considerations are not necessary. If they do, exposure is assessed in a more realistic and precise way using specific parameters. If required, the exposure assessment can be refined using data collected under specific application conditions.

Assessment of risk to users, workers, residents and bystanders due to plant protection products

Based on the exposure assessments described above and the toxicological evaluation of the plant protection product, BfR assesses whether plant protection products, when used correctly, pose a health risk to users, workers, residents or bystanders.

To this end, exposure is compared with the harmful ("toxic") effects of the product or the active substances and other ingredients it contains. The limit values derived from a variety of toxicological studies serve as a measure of harmfulness. An unacceptable risk can only be ruled out if exposure is lower than the relevant toxicological limit value. If necessary, risk mitigation measures can be specified. Such measures may involve the wearing of protective glasses, protective gloves or a protective suit when handling the product. The use of warning signs or minimum waiting times before re-entering treated areas may also be required and set as a condition. If a potential risk of uninvolved persons during application of plant protection products cannot be excluded based on these assessments, the use of special, drift-reducing devices, for example, may be required.

Only when a corresponding risk can be ruled out - if necessary under certain conditions - will BfR consent to the authorisation of a plant protection product.

Result of the risk assessment

The risk is considered acceptable, even for repeated instances of exposure, if the maximum expected exposure falls below the acceptable operator exposure level (AOEL).

As a result of the risk assessment, BfR recommends if necessary:

• Assigning standardised hazard statements, precautionary statements and signal words (i.e. the classification and labelling of the plant protection product)
• Introducing usage restrictions, personal protective measures or further conditions for the safe handling of the plant protection product.

Additional information regarding the principles of risk assessment and the derivation of toxicological limit values such as the AOEL can be found here.

References

The literature cited above can be found in:

• EFSA, Guidance on the assessment of exposure of operators, workers, residents and bystanders in risk assessment for plant protection products, EFSA Journal 2014;12(10):3874
  http://www.efsa.europa.eu/de/efsajournal/pub/3874

An exposure calculation spreadsheet is also available on this page.