​​​​​​​Key message

This core indicator evaluates the status of the marine environment based on concentrations of perfluorooctane sulphonate (PFOS) in Baltic Sea fish. Good status is achieved when the concentrations of PFOS are below the threshold value. The current evaluation considers the assessment period 2011-2015.

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Key message figure 1: Status assessment results based on evaluation of the indicator 'perfluorooctane sulphonate (PFOS)'. The assessment is carried out using scale 4 HELCOM assessment ​​units (defined in the HELCOM Monitoring and Assessment Strategy Annex 4) based on data from stations where 3 or more years of data are available. Click to enlarge.


Good status is achieved for all evaluated areas using all available data up until 2015 to evaluate the assessment period 2011-2015. At present, data are only available from Denmark and Sweden, and there are areas where data are absent, therefore, extended monitoring is required to enable status evaluation throughout the Baltic Sea. Additional data exist from Finland, however with less than 3 years from each station which is required to be included in the aggregated assessment (Key message figure 1.). The ambition is to develop a method to include this type of data with lower uncertainty due to only a few years of monitoring in the coming update of the indicator. Poland experienced data reporting issues which are to be fixed when the report is updated in June 2018.

Time series of PFOS levels in biota show increasing concentrations since the 1970s and 1980s in Baltic Proper and Bothnian Sea. However, in the most recent ten-year period downward trends of PFOS concentrations are observed in the Baltic Sea.

Confidence of the indicator evaluation results is considered to be high for those areas for which data are available.

The indicator is applicable in the waters of all the countries bordering the Baltic Sea.​

Relevance of the core indicator

PFOS is a persistent, bioaccumulative and toxic compound with possible effects on the immune, reproductive and developmental systems as well as lipid metabolism in organisms. It is considered a global environmental contaminant. PFOS has been produced since the 1950s, and has been used for production of fluoropolymers and used commercially to provide grease, oil and water resistance to materials such as textiles, carpets, paper and coatings in general. PFOS has also been used widely in firefighting foams.

The presence of PFOS in biological samples provides information on the contaminant load of the Baltic Sea and reflects the bioavailable part of the contaminant. (Top) predators and humans are exposed to the contaminant through consumption of the species assessed in this indicator. 

Policy relevance of the core indicator

 ​BSAP segment and objectivesMSFD descriptors and criteria

Primary link

Hazardous substances

  • Concentrations of hazardous substances close to natural levels

D8 Concentrations of contaminants

D8C1 Within coastal and territorial andbeyond territorial waters, the concentration of contaminants do not exceed the threshold values

Secondary link

Hazardous substances

  • Fish safe to eat

D9 Contaminants in fish and seafood

D9C1 The level  of contaminants in edible tissues (muscle, liver, roe, flesh or other soft parts, as appropriate) of seafood (including fish, crustaceans, molluscs, echinoderms, seaweed and other marine plants) caught or harvested in the wild (excluding fin fish from mariculture) does not exceed the threshold values

Other relevant legislation: The Water Framework Directive and EC regulation No 850/2004 (and its following amendments) and the Stockholm Convention on Persistent Organic Pollutants. ​ ​

Cite this indicator

HELCOM (2017) Perfluorooctane sulphonate (PFOS). HELCOM Core Indicator Report. Online. [Date Viewed], [Web link]. 

ISSN 2343-2543

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