PFAS ‘forever chemical’
Persistent, accumulative, mobile and hazardous
Pfas facts
What is/are PFAS?
Per- and polyfluoroalkyl substances - PFAS - are a large group of man-made compounds.
PFAS consist of a fully (per) or partly (poly) fluorinated carbon chain connected to different functional groups. Based on the length of the fluorinated carbon chain, short and long chain PFASs can be distinguished. Long chains refer to:
PFAS consist of a fully (per) or partly (poly) fluorinated carbon chain connected to different functional groups. Based on the length of the fluorinated carbon chain, short and long chain PFASs can be distinguished. Long chains refer to:
- perfluorocarboxylic acids (PFCAs) with carbon chain lengths C8 and higher, including perfluorooctanoic acid (PFOA);
- perfluoroalkane sulfonic acids (PFSAs) with carbon chain lengths C6 and higher, including perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonate (PFOS); and
- precursors of these substances that may be produced or present in products.
PFASs, in particular PFSAs and PFCAs, such as PFOS and PFOA, and their precursors have attracted the most attention among PFASs as emerging contaminants (EC) of global concern, “a chemical or material that is characterized by a perceived or real threat to human health or the environment with no published health standard, or an evolving standard.” US EPA have identified on their National PFAS Datasets two lists containing greater than 12,000 PFAS substances-
- PFAS with explicit chemical structures, and;
- PFAS without explicit chemical structures.
What are precursors?
PFOS, PFOA, and PFHxS are usually primary indicators of the presence of a broad range of PFAS compounds including other short and long chain perfluoroalkyl alkyl acids (PFAAs) and precursors (formed by chemical or biological degradation). Precursors are compounds, both known and unknown, which have the potential to form perfluorinated PFCAs and PFSA at degradation. Common PFAS precursor compounds include fluorotelomer alcohols and fluorotelomer sulfonates (used for AFFF).
PFAA precursors refer to chemical structures that can transform and form PFAAs in the environment.
More PFAS compounds are moving and transforming in the environment from:
By solely focusing on targeted PFAS removal, without consideration of the total precursor pool, an unanticipated increase in concentrations of target PFAS may occur over time, resulting in potential future liability. Be sure to read the wack-a-mole comment at the end.
PFAA precursors refer to chemical structures that can transform and form PFAAs in the environment.
More PFAS compounds are moving and transforming in the environment from:
- transportation (via atmosphere, surface water, soil and groundwater),
- partitioning - (mobility- interacting with other environmental chemical processes via air and water where shorter chains are more water soluble and longer chains adsorb and partition to soil more,) and
- bio-transforming in the environment (changing chemical structure and toxicity). Larger chains can degrade to smaller, more persistent forms with comparable toxicities.
By solely focusing on targeted PFAS removal, without consideration of the total precursor pool, an unanticipated increase in concentrations of target PFAS may occur over time, resulting in potential future liability. Be sure to read the wack-a-mole comment at the end.
Where did PFAS come from?
Manufactured in the 1950s, PFASs were the main ingredients in non-stick and waterproofing treatments and coatings. The first firefighting foams with PFAS were created by 3M in the 1960s, and 3M was the sole supplier from the mid-1960s until 1973. The manufacture of PFAS increased in the late 1960s in the United States, especially for use in firefighting foams, and promoted by US Navy. Teflon seemed like a miracle compound for non-stick protective surfaces (frypans, lubricants, etc.). Now it appears that after decades of production and abrasion of treated surfaces the entire earth is polluted with micro-particulate Teflon – arguably the most pernicious form of plastic pollution. Nobody yet fully understands the consequences of pollution from such uses.
What is AFFF?
Aqueous Film Forming Foam (AFFF) also known as Aqueous firefighting foam is a fire suppressant used to extinguish flammable liquid fuel. AFFF Light Water was made by 3M company. AFFF is purchased as a concentrate, typically referred to as “3%” or “6%” depending on its mixture ratio with water.
Prior to 2002, many fluorosurfactants used in AFFF were PFOS-based, which resulted in AFFF that contained PFOS and precursors compounds that could form into PFOS, PFOA and other PFAS of concern. After 3M phased out manufacturing of PFOS-based products in 2000, the primary supply of AFFF, manufacturers replaced long-chain fluorosurfactants with short-chain fluorosurfactants. The PFAS in current fluorotelomer-based AFFF are shorter chain molecules and were suspected to be less toxic. Research is now proving they are just as bad:
PFAS behaviour where AFFF has been used:
Prior to 2002, many fluorosurfactants used in AFFF were PFOS-based, which resulted in AFFF that contained PFOS and precursors compounds that could form into PFOS, PFOA and other PFAS of concern. After 3M phased out manufacturing of PFOS-based products in 2000, the primary supply of AFFF, manufacturers replaced long-chain fluorosurfactants with short-chain fluorosurfactants. The PFAS in current fluorotelomer-based AFFF are shorter chain molecules and were suspected to be less toxic. Research is now proving they are just as bad:
- Environmentally stable and bio persistent anthropogenic compounds.
- 240 compounds belonging to 57 classes have been detected in AFFF.
- 24 have been branded toxic by EPA thus far.
- Toxicities of the rest are unknown due to limited studies.
PFAS behaviour where AFFF has been used:
- PFAS accumulates in the soil or soaks into concrete, pavements.
- Rainwater leaching carries highly soluble compounds through the soil to the groundwater table.
- Surface water run-off dissolves PFAS and carries it to surface water drains and creeks away from original pollution source.
What are PFAS used for?
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PFAS are used to make coatings and products that resist heat, oil, stains, grease, and water because PFAS have:
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They are used in a wide variety of products and processes, e.g., soil, water and oil repellent treatments for carpets and rugs; stain repellent treatments for textiles, leathers and fabrics; in waxes, polishes, paints, adhesives, non-stick cookware, paper and food packaging; pesticides, makeup, baby's products; and industrial uses such as in firefighting foams, aviation hydraulic fluid, metal plating, electronic circuit board manufacture, and oil and gas production (drilling fluids).
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How are we exposed to PFAS?
PFAS are now present virtually everywhere in the world because of the large amounts that have been manufactured and used by international consumers and industry. Exposure occurs when PFAS seeps into food, especially through contaminated water or soil. The chemicals may also build up in animals and plants that come in contact with PFAS. Over time, people may take in more PFAS than they excrete, a process that leads to bioaccumulation in bodies-
- soil and water that helps grow food (livestock, milk, eggs, grain, vegetables, fruit, honey, etc.).
- certain food packaging, (food wrappers, microwaveable popcorn bags, takeaway containers).
- certain foods, including fish, wild fowl and game, bottled water.
- some processing equipment.
- everyday products made to be non-stick, stain-repellent, or water-repellent, (carpet, leather, clothing, packaging material, non-stick cookware [PFOA free frypans is just that, not all PFAS free]).
- personal care products (shampoo, dental floss) and cosmetics (nail polish, eye makeup).
- workers might also breathe in these PFAS substances at places that make PFAS or use them to create other products or exposed via the skin, eg. firefighting foams, landfill waste.
- farmers working the land, driving on dirt roads.
- sources of PFAS to the environment include direct manufacturing discharge to air and water, degradation, and/or precursors released such as the contamination of soil and surface and groundwater.
- PFAS and precursors are also transported great distances in the environment via atmospheric and ocean currents, as evidenced by the detection of PFASs in the Arctic environment in both biota (e.g., polar bears, seals, etc.) and in soils and water.
- PFAS contaminated hotspots, production sites, fire training areas, airports and waste disposal facilities as well as sewage treatment plants can lead to contamination of the environment, which in turn leads to exposure of people living in these areas.
- biosolids from wastewater treatment plants where PFAS is not being removed from the treatment process before recycled and marketed as a beneficial use to irrigate farmland with wastewater and fertilising farmland with PFAS contaminated biosolids.
- breast milk, milk formula, babies via placental transfer.
What is a PFAS dose?
Why are parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt) important measures?
This is how very small traces of chemicals or contaminants in water can be measured when concentrations of small amounts make a big difference. Some PFAS are highly toxic at very low concentrations.
Australia's drinking water guidance values are 70ppt for PFOS and 560ppt for PFOA which is high in comparison to international countries. Australia uses measurement related to nanogram (ppt) or microgram (ppb) per kg of body weight per day. These measurements refer to exposure standards and guidelines created to 'protect' the public from harmful substances that can cause serious health effects. Exposure standards and guidelines are created from risk assessments that include dose-response, exposure, and hazard identification assessments. For consistency when referencing international guidelines ppt are used. PFAS totals are the sum of, which for Australia is just 3 PFAS compounds. Given the many thousands of PFAS that are transforming in our environment and still have poor knowledge about, it is not just about one tiny dose. It is about ongoing exposures and dose concentrations of the different compounds that is the problem
- 'the dose makes the poison'.
This is how very small traces of chemicals or contaminants in water can be measured when concentrations of small amounts make a big difference. Some PFAS are highly toxic at very low concentrations.
Australia's drinking water guidance values are 70ppt for PFOS and 560ppt for PFOA which is high in comparison to international countries. Australia uses measurement related to nanogram (ppt) or microgram (ppb) per kg of body weight per day. These measurements refer to exposure standards and guidelines created to 'protect' the public from harmful substances that can cause serious health effects. Exposure standards and guidelines are created from risk assessments that include dose-response, exposure, and hazard identification assessments. For consistency when referencing international guidelines ppt are used. PFAS totals are the sum of, which for Australia is just 3 PFAS compounds. Given the many thousands of PFAS that are transforming in our environment and still have poor knowledge about, it is not just about one tiny dose. It is about ongoing exposures and dose concentrations of the different compounds that is the problem
- 'the dose makes the poison'.
What is a PFAS half-life?
A half-life is the time it takes for the body to excrete half of the chemical from the body or decompose in the environment. In the environment the half-life of two commonly used PFASs – PFOS and PFOA – is 41 and 90 years respectively. In humans PFOS and PFOA are slowly eliminated from the human body as evidenced by the half-life of 3.3-27 years for PFOS and 2.1-10.1 years for PFOA - Toxicological Profile for Perfluoroalkyls
Example - if you have 10 nanograms of PFAS in your body right now. Even with no additional exposure, five years from now you would still have 5 nanograms. Five years later, you would have 2.5 and then five years after that, you’d have one 1.25 nanograms. It would be about 25 years before all the PFAS leaves your body.
Key determinants to shorter half-life was younger age, higher kidney function and good gut health.
Some excretion occurs through cord blood in pregnant women, and through lactation and menstrual blood loss.
Example - if you have 10 nanograms of PFAS in your body right now. Even with no additional exposure, five years from now you would still have 5 nanograms. Five years later, you would have 2.5 and then five years after that, you’d have one 1.25 nanograms. It would be about 25 years before all the PFAS leaves your body.
Key determinants to shorter half-life was younger age, higher kidney function and good gut health.
Some excretion occurs through cord blood in pregnant women, and through lactation and menstrual blood loss.
- Now consider multiple dosing exposures daily from multiple pathways over longer timeframes. PFAS just keeps increasing in the body, not decreasing - that's bioaccumulation.
What is causation vs association?
Australia started the whole 'nothing to see here' in 2015 using lack of studies to validate Federal Government’s minimiser effect – ‘there is no consistent evidence that PFAS impacts human health’. Australia has still not moved away from this view regardless of new and updated information.
This approach of causation vs association is proving to be more of a get-out clause for government and industry contaminators to avoid effective and responsible decision-making and compensation.
The problem with PFAS, in part, is that there are thousands of chemical structures. If you prove one is bad, we have all these other ones.
The following 2022 US research explains the problem with inaction. Leveraging Systematic Reviews to Explore Disease Burden and Costs of Per- and Polyfluoroalkyl Substance Exposures in the United States
This approach of causation vs association is proving to be more of a get-out clause for government and industry contaminators to avoid effective and responsible decision-making and compensation.
The problem with PFAS, in part, is that there are thousands of chemical structures. If you prove one is bad, we have all these other ones.
The following 2022 US research explains the problem with inaction. Leveraging Systematic Reviews to Explore Disease Burden and Costs of Per- and Polyfluoroalkyl Substance Exposures in the United States
'Given that policy makers raise the high cost of remediation and of substituting PFAS with safer alternatives in consumer products as barriers to confronting adverse health outcomes associated with PFAS exposure, it is important to document the costs of inaction even in the presence of uncertainty...
'We identified PFAS-attributable disease costs in the US of $5.52 billion across five primary disease endpoints shown to be associated with PFAS exposure in meta-analyses. This estimate represented the lower bound, with sensitivity analyses revealing as much as $62.6 billion in overall costs'.
'While further work is needed to assess probability of causation and establish with greater certainty effects of the broader category of PFAS, the results confirm further that public health and policy interventions are still necessary to reduce exposure to PFOA and PFOS and their endocrine-disrupting effects.'
'This study demonstrates the large potential economic implications of regulatory inaction.'
'We identified PFAS-attributable disease costs in the US of $5.52 billion across five primary disease endpoints shown to be associated with PFAS exposure in meta-analyses. This estimate represented the lower bound, with sensitivity analyses revealing as much as $62.6 billion in overall costs'.
'While further work is needed to assess probability of causation and establish with greater certainty effects of the broader category of PFAS, the results confirm further that public health and policy interventions are still necessary to reduce exposure to PFOA and PFOS and their endocrine-disrupting effects.'
'This study demonstrates the large potential economic implications of regulatory inaction.'
What does the science say now - are PFAS harmful?
PFAS are a concern to the environment and human health due to their persistent, bioaccumulation, toxicity (PBT), mutagenic and carcinogenic properties, and their adverse reproductive effects (mutagenic carcinogenic reproduction). Because PFAS half-lives are very long, they accumulate in your body. Typically, when a chemical is harmful it’s because your body thinks it’s something else and it triggers some kind of response. Some PFAS can also cross the blood-brain barrier, and it is proven that some PFAS cross the placental barrier.
Emerging evidence for toxic effects includes:
Emerging evidence for toxic effects includes:
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Human health concerns:
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Known environmental concerns:
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Australia deliberately misrepresenting studies for too long
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In 2016, the U.S. Department of Health and Human Services National Toxicology Program released a immunotoxicity & associated exposure study on PFOS and PFOA (147 pages 7.8MB) concluding that:
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However, the following snip comes from an Australian government Health Effects and Exposure Pathways factsheet that was downloaded in 2019 and still there in 2022. They are referencing the same study yet clearly and deliberately the goal was to mislead and deny the public valuable information to become informed of impacts from PFAS exposures. That factsheet has since been removed in Oct 2022 but can be found on the following archived site.
https://web.archive.org/web/20220308054707/https://www1.health.gov.au/internet/main/publishing.nsf/Content/44CB8059934695D6CA25802800245F06/$File/health-effects-exposure-factsheet.pdf 
See site webpage Research for updated 2023 immunology studies.
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Are the new US PFAS Health Advisory levels measurable?
New health information has become available since 2016, and in June 2022, EPA replaced the 2016 advisories with interim updated lifetime health advisories for PFOA and PFOS based on human epidemiology studies in populations exposed to these chemicals.
Based on the new data and EPA's draft analyses, the levels at which negative health effects could occur are much lower than previously understood when EPA issued the 2016 health advisories for PFOA and PFOS.
The interim updated health advisory levels are:
For comparison, that would be the equivalent of 10 minutes out of the 4.5 billion years the earth has existed.
If PFOA and PFOS can be detected in drinking water, then those levels do pose a likely risk to human health.
There is a lot of conversation about what technology is needed to detect at the levels set but that is progressing.
Any PFAS detected in the water above the new health advisory level set indicates the contamination is too high so the detection becomes the default to give regulators a better gauge of PFAS pollution in drinking water.
The point is the previous levels were so limiting in scope significant levels of PFAS pollutants were being missed.
Based on the new data and EPA's draft analyses, the levels at which negative health effects could occur are much lower than previously understood when EPA issued the 2016 health advisories for PFOA and PFOS.
The interim updated health advisory levels are:
- 0.004 ppt (4 quadrillionths) of the total water for PFOA and
- 0.02 ppt for PFOS, compared to the previous level of 70 ppt for both chemicals.
For comparison, that would be the equivalent of 10 minutes out of the 4.5 billion years the earth has existed.
If PFOA and PFOS can be detected in drinking water, then those levels do pose a likely risk to human health.
There is a lot of conversation about what technology is needed to detect at the levels set but that is progressing.
Any PFAS detected in the water above the new health advisory level set indicates the contamination is too high so the detection becomes the default to give regulators a better gauge of PFAS pollution in drinking water.
The point is the previous levels were so limiting in scope significant levels of PFAS pollutants were being missed.
What do 'observers' say and should PFAS be banned?
'Observers' - scientists, advocates, parents, public officials and more.
'Observers' - scientists, advocates, parents, public officials and more.
“We’re playing whack-a-mole with the public and our children’s health.” "...if we took the tobacco industry’s word on cigarette safety, we would still be waiting.”
Ironically, the tobacco industry played a role in the initial push to inject furniture with flame retardants — a response to society’s growing focus on cigarettes as a cause of fire deaths.
PFAS, the chemicals, are now know colloquially as whack-a-mole where manufacturers develop replacement technologies including reformulating or substituting longer chain substances with nonfluorinated chemicals, alternate technologies, or shorter-chain perfluoroalkyl or polyfluorinated substances. The replacement PFAS may or may not be less hazardous than the long-chain predecessors. Basically, get rid of one of them and the industry markets another as a substitute. Exactly what is happening now - stopped using long chain [8] carbon bond to short chain [6] GenX chemicals. New research a decade on has found that these other short chain PFAS chemicals are just as bad so industry substitute yet another one. It is fair to say that non-conflicted scientists now say that evaluating PFAS one by one will not solve the problem of reducing people's exposure nor stop PFAS impacting the environment. They should be managed as a class of chemicals; government should act quickly and ban the non-essential uses and stop any new production.
Ironically, the tobacco industry played a role in the initial push to inject furniture with flame retardants — a response to society’s growing focus on cigarettes as a cause of fire deaths.
PFAS, the chemicals, are now know colloquially as whack-a-mole where manufacturers develop replacement technologies including reformulating or substituting longer chain substances with nonfluorinated chemicals, alternate technologies, or shorter-chain perfluoroalkyl or polyfluorinated substances. The replacement PFAS may or may not be less hazardous than the long-chain predecessors. Basically, get rid of one of them and the industry markets another as a substitute. Exactly what is happening now - stopped using long chain [8] carbon bond to short chain [6] GenX chemicals. New research a decade on has found that these other short chain PFAS chemicals are just as bad so industry substitute yet another one. It is fair to say that non-conflicted scientists now say that evaluating PFAS one by one will not solve the problem of reducing people's exposure nor stop PFAS impacting the environment. They should be managed as a class of chemicals; government should act quickly and ban the non-essential uses and stop any new production.
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Page last updated 6 January 2024
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