The spraying of liquids with an unmanned aircraft is subject to prior authorization by FOCA. The specific requirements for submitting an authorization request depend primarily on the type of substance being sprayed and the intended use-case.
General
During flight, objects or liquids may only be dropped or dispersed with authorization from FOCA (Art. 9 para. 1 of the DETEC Ordinance on Traffic Regulations for Aircraft (VRV-L; SR 748.121.11)). Depending on the nature of the liquid and its intended use, specific requirements apply.
Applications must be submitted at least 2 months before the intended operation.
To facilitate understanding and help applicants identify the correct procedure, FOCA provides a decision diagram below. Please also consult the links and documents available at the bottom of this page.
Spraying of plant protection products (PPPs) and fertilizers
The use of drones in the agricultural sector mainly involves the dispersion of plant protection products (PPPs) and fertilizers. The operational authorization request is generally based on the PDRA-S01.
Additional regional requirements
Since 15.04.2026, additional requirements apply to operations conducted in the cantons of Valais, Vaud and Geneva. Please refer to the dropdown menu “Additional requirements in the cantons of VS, VD and GE” below.
The drone model used must be homologated by AGROSCOPE.
Each drone’s spraying system (i.e., per serial number) must undergo technical testing by an inspection body approved by the Federal Office for Agriculture before being put into service and every three years thereafter.
The UAS operator must employ at least one person holding a permit for the use of plant protection products (OPer-A; RS 814.812.34). More information on the acceptable diplomas/permits can be found on the FOEN website (DE/FR/IT).
The operator must comply with specific operating conditions, regardless of the type of authorisation requested (maximum flight height and speed, weather conditions, minimum distances from people, etc.). These conditions are described in the FOCA-UAS-APP-AGRI form (see “Required documents” below).
Due to the high number of helicopters performing aerial spraying operations in the cantons of Valais, Vaud and Geneva, specific requirements have been introduced. These aim to ensure safe coexistence and effective coordination between airspace users.
For drone operators and remote pilots, this notably involves the use of an online mapping tool (SafetySpray) as well as radiotelephony. The document below provides detailed information on these requirements (coming soon in English). The interactive map allows users to visualise the concerned areas (in red) and determine whether an operation is subject to these requirements. FOCA’s UAS section is available to answer any questions on this topic.
As for any drone operation in the Specific category, an authorisation from FOCA is required. For aerial spraying operations involving plant protection products and fertilisers, the application is generally submitted on the basis of PDRA-S01 (see form below), whose conditions well apply to the types of operations and drones concerned. It is also possible to submit an application based on another PDRA or a SORA. In this case, it is recommended to contact FOCA in advance.
In addition, the following documents must be submitted, together with the required supporting documents (e.g. operations manual, copy of the authorisation for the use of plant protection products, etc.):
Spraying of chemical substances and/or preparations
Any person releasing a substance or preparation into the environment must ensure that human health is not endangered and that the environment is not adversely affected. This obligation also applies to spraying operations conducted by drones. Appropriate measures must be taken to prevent any exposure of people and the environment to chemical products within the spraying area.
Chemical substances and preparations must be declared, regardless of their quantity. In addition, new substances (i.e. those not fully registered in the EU under the REACH Regulation) must be subject to an additional notification before being placed on the market if their quantity exceeds one tonne per year (see this page of the Common notification authority for chemicals).
Applicants must first consult the information documents available below.
In addition, in accordance with the principle of self-control, applicants must consult the Common notification authority for chemicals of the FOEN - FOPH - SECO (link), as well as the Chemicals Product Register (RPC), in order to verify any prohibitions and restrictions applicable to the chemical products intended for spraying. An overview of the relevant requirements is available on the FOEN website.
As for any drone operation in the Specific category, an authorisation from FOCA is required. The application is generally submitted on the basis of PDRA-S01 (see form below), whose conditions well apply to the types of operations and drones concerned. It is also possible to submit an application based on another PDRA or a SORA. In this case, it is recommended to contact FOCA in advance.
The use of biocides with drones requires coordination between FOCA (for the aeronautical aspects) and other relevant offices (FOPH, FOAG, SECO and FOEN, for the biocides aspects).
Applicants must first consult the Biocidal products page of the Common notification authority for chemicals in order to familiarise themselves with the rules applicable to the biocidal products they intend to use. Biocidal products may be placed on the market, be used professionally and commercially only if they have been authorised, notified or recognised according to the Ordinance on Biocidal Products (OBP; SR 813.12).
As for any drone operation in the Specific category, an authorisation from FOCA is required. The application is generally submitted on the basis of PDRA-S01 (see form below), whose conditions well apply to the types of operations and drones concerned. It is also possible to submit an application based on another PDRA or a SORA. In this case, it is recommended to contact FOCA in advance.
From a substance regulation perspective, the spreading of organisms does not require any specific approval. However, from an aeronautical standpoint, the operation still requires authorization from FOCA.
As for any drone operation in the Specific category, an authorisation from FOCA is required. The application is generally submitted on the basis of PDRA-S01 (see form below), whose conditions well apply to the types of operations and drones concerned. It is also possible to submit an application based on another PDRA or a SORA. In this case, it is recommended to contact FOCA in advance.
In addition, a list of the organisms to be sprayed must be provided.
Spraying of water
Spraying pure water does not require authorisation from a substances perspective. However, an authorisation from FOCA is still required from an aviation perspective. Spraying operations, including water, are not permitted under standard scenarios (STS). Operators using C5/C6 drones are encouraged to apply under PDRA-S01 or PDRA-S02, the operational equivalents of STS-01 and STS-02, to simplify the process and reduce processing times.
Based on time spent, i.a.w. Art. 38, Para. 1, let. a of the Ordinance on the fees charged by the Federal Office of Civil Aviation (GebV-BAZL; SR 748.112.11).
