Per- and poly-fluoroalkyl substances

Per- and poly-fluoroalkyl substances, or “PFAS”, are a class of manufactured chemicals, used since the 1950s, to make products that resist heat, stains, grease and water. Products that may contain or release PFAS include furniture and carpets treated for stain resistance, foams used for firefighting, fast food or packaged food containers, make up and personal care products and cleaning products. 

The PFASs of most concern are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Perfluorohexane sulfonate (PFHxS) is another chemical of the PFAS group and is present in some fire-fighting foams and used as a raw material or precursor to produce other PFAS based products.

Many countries have phased out, or are in the process of phasing out the use of PFOS and PFOA due to concerns about their persistence, bioaccumulation and toxicity. Because of their widespread use, people in Australia commonly have some PFOS, PFHxS and PFOA in their body.

In Australia and internationally, where the use of PFASs has become restricted, a general trend towards lower PFAS levels in a person's body has been observed.

The Australian Government has been working since 2002 to reduce the importation of some PFASs and has recently committed to a number of health initiatives (external site) to assist communities affected by PFAS contamination.

The source of the guidance information on this site is the Environmental Health Standing Committee (enHealth) guidance statement (PDF 64kB) (external site).

Health impacts from exposure to PFOS and PFOA

There is currently no consistent evidence that exposure to PFOS and PFOA causes adverse human health effects.

Because these chemicals persist in humans and the environment, it is recommended that human exposure to these chemicals is minimised as a precaution. 

In chronic exposure studies on laboratory animals, research into PFOS and PFOA has shown adverse effects on the liver, gastrointestinal tract and thyroid hormones. However, the applicability of these studies to humans is not well established.

The existing limited studies on PFHxS suggest that this chemical can cause effects in laboratory test animals similar to the effects caused by PFOS. However, based on available studies, PFHxS appears to be less potent in animal studies than PFOS.

In humans, research has not conclusively demonstrated that PFASs are related to specific illnesses, even under conditions of occupational exposure. Recent studies have found possible associations to some health problems, although more research is required before definitive statements can be made on causality or risk.

Major human exposure pathways

Outside of the occupational setting, exposure to PFASs can occur from the air, indoor dust, food, water and various consumer products. For most people, food is expected to be the primary source of exposure to these chemicals. Human breast milk may contribute to exposure in infants since some PFASs have been detected in human breast milk.

Because the human body is slow to rid itself of PFOS, PFOA and PFHxS, continued exposure to these chemicals can result in accumulation in the body. Due to the potential for accumulation, and while uncertainty around their potential to cause human adverse health effects remains, it is prudent to reduce exposure to PFASs as far as is practicable. This means that action needs to be taken to address the exposure source or possible routes of exposure.

For some communities near facilities where PFOS, PFOA and PFHxS have been extensively used, higher levels may be found in the surrounding environment and exposure may occur through other means, including drinking water supplied from groundwater. Determination of exposure is best achieved through a full human health risk assessment that examines all routes of exposure. Information on PFAS investigations in Western Australia is available from the Department of Water and Environmental Regulation (external site).

Reference values for PFOS and PFOA

On 3 April 2017, the Australian Government Department of Health published final health based guidance values (external site) for use in site investigations across Australia for PFOS, PFOA and PFHxS.

Breast feeding
The significant health benefits of breast feeding are well established and far outweigh any potential health risks to an infant from any PFOS or PFOA transferred through breast milk.

The DOH does not recommend that mothers living in or around sites contaminated with PFOS or PFOA cease breast feeding.
Pregnancy
There is currently no consistent evidence that exposure to PFOS or PFOA causes adverse human health outcomes in pregnant women or their babies.

Nonetheless, the DOH recommends that pregnant women should be considered a potentially sensitive population when investigating PFOS and PFOA contaminated sites, with a view to minimising their exposure to PFOS and PFOA.
Blood tests

There is currently no accepted clinical treatment to reduce levels of PFASs in the human body.

Given the uncertainty that PFASs are directly linked to adverse health outcomes, blood tests cannot determine if the PFAS levels in a person’s blood will make them sick now or later in life.  Therefore, individual blood tests are not recommended to determine whether any medical condition is attributable to exposure to PFOS or PFOA and have no current value in informing clinical management, including diagnosis, treatment or prognosis in terms of increased risk of particular conditions over time.

In the absence of a blood test being definitive in informing individual risk and clinical management, exposure reduction is the key measure to reduce any possible risks posed by PFASs.

At a population level, blood tests can inform a community that they have been exposed to PFASs at a level above that of the general population. The monitoring of pooled community blood samples over time may help determine the success of exposure reduction measures.