Decision tree for prioritising sites potentially contaminated with per- and poly-fluoroalkyl substances (PFAS)

The NSW Environment Protection Authority (EPA) is implementing a statewide strategy during 2016 and 2017 to identify facilities in NSW where the use of per- and poly-fluoroalkyl substances (PFAS) may have resulted in site contamination. This includes sites which may have been notified as potentially contaminated and where there may have been significant releases to the environment in the past, including at firefighting training sites, airports, and some industrial sites.

What are PFAS?

PFAS are a group of chemicals that include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).

Assessing the health effects

Recently, experts in the Australian Environmental Health Standing Committee (enHealth) considered relevant international scientific evidence and found that there is currently no consistent evidence that exposure to PFOS and PFOA causes adverse human health effects. However, based on the evidence from animal studies, potential adverse health effects cannot be excluded. enHealth has set interim tolerable daily intake values for areas of site contamination, and has also requested Food Standards Australia New Zealand (FSANZ) to undertake further assessment of the available toxicity data. Values published by FSANZ will immediately replace interim toxicity reference values recommended by enHealth. Further information is available from NSW Health.

Sample analysis using the decision tree

The EPA has collected screening samples of soils and waters for analysis. Screening sample analysis results for PFAS are assessed through the use of a decision tree. The decision tree for prioritising sites potentially contaminated with PFAS (PDF 465KB) was developed for the EPA by Environmental Risk Sciences Pty Ltd (EnRisks). This process will indicate the priority for further testing and investigation to evaluate the nature and extent of the contamination, and whether there are any likely exposure pathways.

Find out more about the EPA’s investigative process to assess the use of PFAS across NSW.


The EPA is working with the NSW Government and its interstate and international colleagues to ensure that appropriate screening criteria are being applied as knowledge about these chemicals develops.

Where the contamination is significant, the EPA will use appropriate regulatory tools to work with the occupiers and owners of these sites to ensure that further investigation and appropriate clean-up or management of the contamination takes place.

The decision tree is neither ‘made’ nor ’approved’ by the EPA under the Contaminated Land Management Act 1997, which means it holds no authority in law. The decision tree will be used to prioritise sites for further investigation and to rule out low-risk sites, and must be applied consistently with made and official guidelines.

More information

If you have any questions about the decision tree for prioritising sites potentially contaminated with perfluorinated compounds or the EPA’s PFAS investigation program, please call Environment Line on 131 555 or email

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