Medicines and chemicals
Fish farms need a range of medicines and products containing chemicals, such as disinfectants and antifoulants to ensure the health and welfare of the fish they grow and to maintain and protect the farm infrastructure and equipment (e.g. pens and boats). The medicines and products used on fish farms are approved and regulated through chemicals legislation (e.g. Biocidal Products Regulations) or veterinary medicines regulations (VMR) by the Health and Safety Executive (HSE) and Veterinary Medicines Directorate (VMD) respectively.
SEPA regulates discharges from fish farms in order to protect the environment. In the case of some products, SEPA sets controls or limits on the quantities that are allowed to be used and discharged so that environmental standards are met and the environment is protected.
SEPA regulates discharges of medicines and chemicals from finfish aquaculture in two ways:
- substances or products that pose no or low environmental risk and which require no site-specific risk assessment may be added to the Permitted Substances List.
- substances or products that do not meet the no or low environmental risk threshold will be added to the permit with conditions controlling use to ensure that environmental standards are met.
However if during the assessment a method of use or discharge of a substance or product in the latter category can be identified that meets the no or low environmental risk threshold, then that substance or product may be added to the permitted substances list for that use only.
Authorisation and regulation of discharge treatment solutions from wellboats passed from the Marine Directorate to SEPA in November 2020.
Veterinary medicines
A veterinary medicine or veterinary medicinal product (VMP) is defined as "any substance or combination of substances presented as having properties for treating or preventing disease in animals; or that may be used in, or administered to, animals with a view either to: restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action".
SEPA currently sets limits on the amount of certain sea lice medicines that can be used. These include in-feed treatments, where the medicine is incorporated into food pellets and bath treatments, where the medicine is mixed with the seawater in which the fish swim. Other medicines, for which SEPA does not currently set limits, include vaccines, anaesthetics and antibiotics.
It is an operator’s responsibility to identify the medicines that will be required and to ensure these medicines can legally be used in the UK. For medicines which do not meet the low or no environmental risk threshold it may be necessary for the operator to complete modelling to understand the potential dispersion of the medicine in the environment. It may also be a requirement that the operator undertakes monitoring to understand the baseline levels of medicines in the environment and the residual concentrations in the environment following the use of such medicine.
Further information and guidance
- Regulatory modelling process and reporting guidance
- Baseline survey and monitoring plan design
- Interim position statement for protecting the water environment in relation to emamectin benzoate in finfish farm regulation
- Temporary regulatory position statement - Substances permitted to be discharged from finfish farm facilities – Bronopol
- Temporary regulatory position statement - Substances permitted to be discharged from finfish farm facilities – Benzocaine
- Temporary regulatory position statement - Substances permitted to be discharged from finfish farm facilities – Tretrasodium EDTA
- Temporary regulatory position statement - Substances permitted to be discharged from finfish farm facilities – Deltamethrin
Permitted substances list
The permitted substances list (PSL) is produced by SEPA following a screening environmental risk assessment. A request for a substance or product to be included in the PSL can be made to SEPA by an operator, supplier or manufacturer. Information on the product and its active ingredients must be supplied (e.g. UK approval, chemicals properties, aquatic toxicity, formulation) as well as information on how the product is intended to be used (purpose, where, how, estimated volume/quantity) to allow an assessment to be completed. SEPA will undertake a review of the permitted substances list annually to ensure that the list is current.
In some circumstances a substance or product, which would normally require a permitted limit, may be included in the PSL provided that the proposed method of use or discharge meets the no or low environmental threshold. If these criteria are met then the product or substance may be added to the PSL for that use only.
Emamectin benzoate position
The statement below sets out the regulatory position on the environmental standard that we will apply in determining applications for new and increased discharges of emamectin benzoate into the marine environment.
The new environmental standard for emamectin benzoate was recommended by the UK Technical Advisory Group (UKTAG) following a review of the latest scientific evidence on the toxicity of the medicine to aquatic life. Following a public consultation in 2023, in June 2024, the Scottish Government published its analysis of responses and confirmed that it will direct SEPA to implement licences to discharge the medicine.
Supporting Information
The following reference documents provide information on aspects of medicine usage.
- Guidance note on the licensing of discharges of Panacur (fenbendazole) at marine cage fish farms
- Guidance note on the licensing of discharges of AMX (deltamethrin) at marine cage fish farms
- Supplement 1 - Guidance on dealing with technical variations to add AMX (deltamethrin) to licences for marine cage fish farms
- Cage Fish Farms: Sea Lice Treatment Chemicals Risk Assessment of Azamethiphos