Delousing Agents

The Fish Site
by The Fish Site
10 February 2010, at 12:00am

NORWAY - In the interest of maintaining food safety, the content of pharmaceuticals present in farmed fish is monitored. These pharmaceuticals include several delousing agents, such as the two substances diflubenzuron and teflubenzuron.

Monitoring data for delousing agents in farmed fish has never revealed residue levels above the internationally established maximum limits. Accordingly, they have not been affecting seafood safety.

Since 2002, fillet samples from 6200 farmed fish have been analysed at the National Institute of Nutrition and Seafood Research, (NIFES) for their content of eight different delousing agents. For the two compounds diflubenzuron and teflubenzuron, which have recently received some attention in Norway, samples of 645 fish have been analysed.

  • No delousing agent approved for use in fish farming, has been detected above the internationally set maximum residue limits (MRL) in fish for human consumption.
  • Diflubenzuron and teflubenzuron, have never been detected in fish filets. The method used for analyzing these substances are sensitive and enable the detection of diflubenzuron and teflubenzuron at a level of one per cent of the MRL.
  • No residues of illegal delousing agents have been detected.

Surveillance of delousing agents in fish is part of the annual monitoring programme on undesirable substances in farmed fish, which is initiated by an EU directive on surveillance of foods of animal origin. The number of analyses per year is determined by the production volume and most of the samples are therefore of Atlantic salmon. In 2008, approximately 9000 samples were analyzed. The Norwegian Food Safety Authority is responsible for implementing the directive in Norway and NIFES performs the chemical analyses and risk assessment.