Purity of fish feed is important: concentrations of dioxins and PCBs are below limit values


<p>Feed for farmed fish consists mainly of products of marine origin. Fish feed may contain hazardous substances which may end up to farmed fish. The Finnish Food safety Authority Evira and the National Institute for Health and Welfare (THL) studied the occurrence of persistent organic pollutants in fish feed and its raw materials. Fish has many beneficial properties from a human health perspective. However, organic hazardous substances in fish feed may accumulate into fish. Fish meal and fish oil may constitute 50–70% of all material in fish feed. Fish meal is a powder-like substance made of fish and fish trimmings with a dry matter content of over 90 %.</p>

Evira and THL studied the occurrence of dioxins (PCDD/F), polychlorinated bifenyls (PCB), polybrominated diphenyl ethers (PBDE), perfluorinated alkyl compounds (PFAS) and organotin compounds (OT compounds) in fish feed and its raw materials fish oil and fish meal. Concentrations of dioxins and PCBs in all the samples were below the limit values of the EU.

Concentrations of PBDEs and PFASs in this study were similar or lower than those measured in fish and fish feed elsewhere in the world. Concentrations of organotin compounds in fish feed and its raw materials were relatively low as compared to concentrations in fish elsewhere in the world. There was significant variation in concentrations of the studied compounds even within each product category (fish oil, fish meal, fish feed). There are no limit values for concentration of other studied compounds in feed than for dioxins and PCBs.

Dioxins have never been commercially manufactured but they are formed for instance in incineration processes. PCBs have been used in lubricants and in the electronics industry. PBDEs are used as fire retardants in plastics, interior textiles and in the electronics industry. PFASs are used in extinguishing foams and as water-repellent agents in textiles. Organotin compounds have been used as fungicides and in antifouling paints for vessels. Today PCBs are globally banned and the use of other above mentioned chemicals have been globally restricted.

This study is a follow-up to Evira’s previous projects on contaminants in the Baltic fish ( EU-fish-projects 2002–2011). The description is in English.

The article:
K. Suominen, A. Hallikainen, P. Ruokojärvi, R. Airaksinen, J. Koponen, R. Rannikko, H. Kiviranta: Occurrence of PCDD/F, PCB, PBDE, PFAS, and Organotin Compounds in Fish Meal, Fish Oil and Fish Feed. Chemosphere 85 (2011) 300–306.

Further information:
Kimmo Suominen, Researcher, Risk Assessment Research Unit
tel. +358 40 827 9715, kimmo.suominen at-merkki.gif : 1Kb evira.fi

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