Per- and polyfluoroalkyl substances, commonly known as PFAs, are a large family of synthetic chemicals prized for their unique properties, but also increasingly scrutinised for their environmental persistence. These compounds are widely used in industry and consumer products, and understanding their chemistry helps explain both their usefulness and the challenges they present.
What are PFAs?
PFAs are characterised by carbon-fluorine bonds, which are among the strongest in organic chemistry. This strong bond gives PFAs remarkable stability, resistance to heat, and the ability to repel water, oil, and grease.
The family includes thousands of individual substances, from well-known compounds such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) to less widely recognised variants. Their molecular structures typically feature fully or partially fluorinated carbon chains, which are key to their performance.
Properties that make PFAs unique
The chemical and physical characteristics of PFAs explain why they have been so widely adopted:
Hydrophobic and lipophobic: repels water, oils, and stains
Thermally stable: withstands high temperatures without breaking down
Chemically inert: resistant to acids, bases, and most solvents
Durable and persistent: can last for decades in environmental settings
These properties make PFAs highly effective in applications where durability, water- and oil-resistance, or chemical stability are required.
Industrial and consumer applications
PFAs have been used across a wide range of sectors:
Textiles and apparel: water- and stain-resistant coatings for performance fabrics and outdoor gear
Non-stick cookware: fluoropolymer coatings that prevent sticking and allow easy cleaning
Firefighting foams: aqueous film-forming foams (AFFFs) for industrial and aviation fire suppression
Electronics and industrial chemicals: lubricants, coatings, and surfactants that require chemical or thermal resistance
Their versatility has made PFAs a go-to solution in situations where other chemicals would degrade too quickly or fail to provide the same level of protection.
Environmental and health considerations
PFAs are often called “forever chemicals” because of their extreme resistance to natural breakdown. This persistence means they can accumulate in water, soil, and living organisms over time. For humans, exposure occurs mainly through contaminated drinking water, food, or household products containing PFAs.
Studies have linked certain PFAs to a range of health concerns. These include:
Hormonal disruption: PFAs can interfere with endocrine function, affecting thyroid hormone levels and other regulatory systems.
Liver and kidney effects: some PFAs have been associated with changes in liver enzymes and kidney function over prolonged exposure.
Immune system impacts: evidence suggests PFAs may reduce antibody response to vaccines and impair overall immune function.
Developmental effects: prenatal exposure has been linked to lower birth weights and potential delays in child development.
Cancer risk: certain long-chain PFAs, such as PFOA, have been classified as possibly carcinogenic based on epidemiological studies.
Because of these potential risks, regulators in Europe, North America, and Asia are actively monitoring PFAs in water supplies, food packaging, and consumer goods. Ongoing research continues to clarify which compounds pose the greatest risk and at what levels, informing safer manufacturing practices and exposure limits.
Regulatory trends
Globally, regulators are taking action to manage PFAs:
Europe: REACH regulations restrict certain PFAs, particularly those with known persistence and toxicity, while encouraging alternatives.
United States: The EPA has set health advisories for PFOA and PFOS in drinking water and is exploring limits for other PFAs.
Asia-Pacific: Countries including Japan, South Korea, and Australia have begun regulating or phasing out specific PFAs in consumer and industrial products.
These regulations reflect growing concern over environmental persistence and human health, prompting industries to seek safer alternatives where possible.
The future of PFAs
PFAs continue to be valuable for applications requiring chemical stability and water- or oil-repellent properties. However, increasing regulatory pressure and public scrutiny are accelerating the search for alternative chemistries that provide similar performance without the long-term environmental impact.
Like many chemicals used in industry, PFAs illustrate the balance between functionality and responsibility. Their unique chemistry has enabled countless products to perform better, but it also presents challenges that modern chemical science must address.