General recommendations on disinfection

Article 4.3.1.

Disinfection is employed as a common disease management tool in aquaculture. Disinfection procedures should be part of a disinfection programme designed for a specific purpose. Disinfection may be used in biosecurity programmes to eradicate or exclude specific diseases from aquaculture establishments, as well as a routine sanitary measure to reduce disease incidence within aquaculture establishments.

Disinfection of installations and equipment and transport units should be carried out using procedures that prevent the contamination of other water and other aquatic animal populations with infectious material. There is a great variety of products and procedures for washing and disinfecting installations or equipment used in aquaculture establishments or for treating effluents, and wastes from quarantine and processing plants. The decision on which product to use should take into account their microbiocidal efficacy, their safety for aquatic animals and the environment.

Article 4.3.2.

The manufacturer’s instructions for effective use of a disinfectant under aquaculture conditions should be followed. disinfectants to be used in aquaculture should be evaluated/tested against relevant aquatic pathogens under relevant conditions. Approved procedures for the use of disinfectants in aquaculture should be established.

The efficacy of disinfection is affected by various factors, including temperature, pH, and the presence of organic matter. At high temperatures, the disinfecting action is faster as long as the decomposition of the disinfectant does not occur. At low temperatures, the biocidal efficacy of most disinfectants decreases. Many disinfectants have an optimum pH range/level, and product choice should depend on the pH of the diluent (water). For example, quaternary ammonia is more efficient at alkaline pH while iodine and iodophores are more efficient at neutral or acid pH. The presence of organic material and greasy substances may significantly reduce the efficacy of a disinfectant. Therefore, surfaces should be cleaned thoroughly before applying disinfectants.

The use of disinfectants may require measures to protect personnel, aquatic animals and the environment. The manufacturer’s instructions for safe use and disposal should be followed.

Article 4.3.3.

Specific disinfection procedures are provided in Chapter 1.1.3. of the Aquatic Manual.