Per- and polyfluoroalkyl substances
Although per- and polyfluoroalkyl substances have only been manufactured and in use since the 1940s, they are now to be found everywhere – even in remote, unsettled regions. Due to concerns about their effects on humans and the environment, five European countries now want to ban them. What is it that makes them so dangerous?
Table of contents
- What are per- and polyfluoroalkyl substances?
- Quality Analysis analyses your industrial or environmental sample
- The characteristics of per- and polyfluoroalkyl substances
- Why are PFAS so problematic?
- How to verify the presence of per- and polyfluoroalkyl substances
- For what purpose are PFASs used and which products can contain PFASs?
- Identification and avoidance of PFASs in products
- Summary: per- and polyfluoroalkyl substances
What are per- and polyfluoroalkyl substances?
The term per- and polyfluoroalkyl substances (PFASs) covers a large group of organic compounds. These substances are characterised by varying length carbon chains in which hydrogen atoms have been replaced entirely (perfluorinated) or partially (polyfluorinated) by fluorine atoms. This modification gives the molecules high chemical stability and persistence, because carbon-fluorine bonds have low reactivity.
Quality Analysis analyses your
industrial or environmental sample
Quality Analysis, as an independent and accredited test laboratory, can assist you during the verification of the presence or absence of per- and polyfluoroalkyl substances in your samples and during the manufacture of certified, PFAS-free components. Our expertise in the measurement of the total concentration of organic fluorine compounds by means of the determination of sum parameters such as TF, TOF, AOF and EOF permits a comprehensive evaluation of PFAS levels.
- Analysis of the total fluorine content TF and the sum parameters TOF, AOF and EOF to determine the overall levels of PFAS in your sample
- Combustion ion chromatography (CIC) for precision and the highest accuracy
- Our efficient processes guarantee quick and reliable fluorine analysis
- Suitable for many sectors: from the management of the environment and water resources, through the paper and packaging industry, the textile industry, to the cosmetics industry and medical sector
The characteristics of per- and polyfluoroalkyl substances
In addition to their stability and persistence, per- and polyfluoroalkyl substances are characterised by their unique ability to withstand exposure to thermal and chemical effects. At the molecular level, the electronegativity of fluorine also provides a powerful force that attracts the fluorine to the carbon atom. In this way, the bond energy is increased and the molecules are particularly resilient to decay. This molecular strength means that PFASs are not only difficult to break down, they also have little tendency to react with other substances. Although this situation makes them valuable for many industrial processes, it also contributes to their environmental persistence.
A physical characteristic of PFASs is their ability to act on surfaces and form a protective barrier there. This property is due to the balance between the hydrophobic (water-repellent) and oleophobic (oil and grease-repellent) parts of the molecule. These special characteristics permit the varied use of PFASs, e.g. as dirt, grease and water-repellent coatings, as an additive to fire extinguishing media, as part of cooking utensils, in cosmetics, etc.
Why are PFAS so problematic?
Despite these useful characteristics, research is increasingly aimed at understanding the long-term effects of PFASs on the environment and human health. The search for safe, sustainable PFAS alternatives is taking on a central role here to reduce dependency and minimise the release and accumulation of harmful substances in the environment.
PFAS: persistence and toxicity
The wide-ranging applications and chemical stability of PFASs pose significant risks for the environment and health. Their persistence causes them to accumulate in the environment and means they can reach remote regions by means of waterways and atmospheric transport. PFASs accumulate in the food chain in ecosystems and, finally, also reach humans where they are associated with a series of health problems. Their toxicity and the difficulty of removing them from the environment once released represent important challenges.
The health risk of PFAS
In particular perfluorinated sulphonic acids and perfluorinated carboxylic acids have led to concerns and stricter regulations due to their potential health risks and their persistence in the environment. Studies have shown that long-term exposure to certain PFASs is associated with an increased risk of various illnesses, including cancer, liver diseases, thyroid disorders and immunological effects. PFASs can also impair the development of fetuses and small children.
How to verify the presence of per- and polyfluoroalkyl substances
The analysis of per- and polyfluoroalkyl substances (PFASs) is a specialised field that requires the use of various methods. PFAS analytics is particularly important for meeting regulatory requirements and assessing the effectiveness of decontamination methods. For this purpose, both individual PFAS compounds and the overall PFAS level can be identified and quantified in samples. This differentiation between individual substance analytics and the analysis of sum parameters is crucial for a comprehensive understanding of PFAS contamination.
Individual substance analytics of PFAS compounds
Individual substance analytics aims to identify and quantify specific molecules of PFASs in samples. High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) is the method of choice here. This technique permits the highly precise identification of individual PFAS compounds based on their unique mass-to-charge relationships. In this manner, the substances listed in the table can be analysed individually.
The limits of individual substance analytics
While individual substance analytics can theoretically provide detailed information about specific PFASs in a sample, it also has significant disadvantages. The basic problem is that many of the thousands of compounds in the PFAS group have not yet been sufficiently characterised or limits specified. There is therefore no comprehensive framework for the evaluation of their risk potential. For this reason, individual substance analytics is often not able to identify the full scope of contamination. As such, environmental and health risks may be underestimated, because the analysis does not take into account unknown PFASs or PFASs not subjected to specific testing.
The analysis of PFASs by determining the sum parameter
In contrast, sum parameter analytics concentrate on the determination of the overall levels of organic fluorine compounds in a sample – with more than 10,000 individual compounds in the PFAS group, in most situations it is the better choice. One method for the analysis of the sum parameters AOF and EOF is combustion ion chromatography (CIC), which measures the total fluorine content (including non-PFAS) and therefore provides an indirect indication of the PFAS levels. The biggest advantage of this method is its efficiency, because it permits quick estimation of the overall levels of fluorine, even if the specific compounds are unknown. This thorough chemical analysis permits the effective measurement of numerous PFAS compounds and provides an essential basis for environmental protection measures and the evaluation of health risks. These characteristics make it ideal for screening purposes or for the ongoing evaluation of contamination.
For what purpose are PFASs used and which products can contain PFASs?
Per- and polyfluoroalkyl substances are used in many processes and products in various industries due to their particular characteristics. Their water, grease and dirt-repellent properties as well as their extraordinary chemical stability and durability make them a preferred constituent in many applications. They are used, for example, on textiles, leather and paper to make them heat, water and grease-repellent. As such, the use of PFASs for outdoor clothing, shoes, carpets and packaging materials is attractive. Furthermore, PFASs are used in chromium plating and the manufacture of semiconductors where their stable, repellent characteristics are indispensable. In paper production, in impregnating agents and preserving agents, as well as in the automotive and construction industry, they are used to make products more durable and to provide protection against dirt. PFASs are also often to be found in floor and vehicle care products, because they form a protective barrier against moisture and dirt. In paints and lacquers, PFASs improve the durability and ease of maintenance of surfaces. And PFASs are even used in cosmetic products such as mascara and creams, to name but a few of the applications of PFASs.
Identification and avoidance of PFASs in products
The identification of products without PFASs can be a challenge, because these chemicals are not always listed on product stickers. One way of ensuring that a product is free of PFASs is to check for specific labels. An example is the Oeko-Tex label for which strict environmental and health standards must be met.
Consumers can also contact the manufacturer directly to request information about the use of PFASs in their products. It is also helpful to find out about sector-specific standards and guidelines, because some sectors have already taken steps to reduce or eliminate the use of PFASs.
Summary: per- and polyfluoroalkyl substances
Per- and polyfluoroalkyl substances (PFAS) are a comprehensive group of synthetic chemicals used in numerous products due to their water, grease and dirt-repellent characteristics. As a consequence of their chemical stability and persistence, PFASs accumulate in the environment and are difficult to break down resulting in significant risks for human health and the environment.
