New Plant Protection Product Risk Indicators for Switzerland

Agroscope has developed risk indicators for plant protection products. These indicators highlight risk trends over time for important environmental compartments. Based on sales volumes of active substances, they take account of specific risk reduction measures.

Plant-protection products (PPPs) are used in agriculture to protect crops and their products. They are also used in forestry and in the upkeep of public and private green spaces, as well as in the maintenance of railway and street infrastructure. Used over large areas, PPPs do not remain exclusively where they are applied, but may end up via various entry routes in other environmental compartments, where they can have undesirable effects on non-target organisms.

Parliamentary Initiative for PPP risk reduction

As part of Parliamentary Initiative 19.475, the Swiss Parliament has set the target of reducing the risk of using PPPs by 50% compared to the 2012–2015 reference period by the year 2027. In this way, the Parliament aims to better protect organisms in surface waters and semi-natural habitats as well as groundwater from PPPs. Agroscope was tasked with developing three risk indicators capable of illustrating the risk trends for these three environmental compartments.

PPP active substances differ in terms of toxicity and behaviour in the environment

Developing such risk indicators is highly complex, as the various PPP active substances differ in terms of toxicity and environmental behaviour. Since no area-wide data on PPP use are available, the quantities of all active substances sold as of 2012 serve as the calculation basis. The aim is to show the effects of the risk reduction measures decreed by the approval, the measures (regarding drift and runoff) envisaged for the future as part of the Proof of Ecological Performance (PEP), and measures such as the remediation of cleaning areas for the spraying equipment, as well as to present the extent of implementation of the different measures.

Calculating the risk indicators

To calculate the individual risk indicators, a treated area is determined for each active substance and multiplied by a risk score as well as by a factor for risk reduction. The active substance-specific sales volumes and the average approved application rates of the active substances per area serve as a basis for the treated area. The risk score is based on the substance properties that determine transport into the respective environmental compartment. It is calculated by means of a standardised application per active substance and environmental compartment. For the risk indicators ‘Surface Waters’ and ‘Semi-natural Habitats’, the toxicity for organisms in the corresponding environmental compartment is also taken into account. Risk reduction results from the various risk reduction measures and their implementation.