FFKM, or perfluoroelastomers, are a group of elastomers that are used across a wide range of industries.
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PFAS regulation is currently one of the most widely discussed topics in the polymer and elastomer industry. Though PFAS chemicals are used across a wide variety of critical applications, including electronics and semiconductors, automotive, aerospace, medical devices and chemical manufacturing and processing, their use is under increasing scrutiny. The European Chemicals Agency (ECHA) is currently evaluating a proposal to heavily restrict over 10,000 per- and polyfluoroalkyl substances (PFAS) due to their persistence and risk to the environment and human health.
Understanding the difference between fluoropolymers, polymerisation aids and residual substances is essential when selecting materials for demanding industries such as hydrogen systems, chemical processing, aerospace and semiconductor manufacturing.
This article explains the fundamentals of PFAS in polymers, the role of fluoropolymers in sealing technology, how evolving REACH regulation may affect the supply chain, and what you need to know about their upcoming regulation when choosing the most appropriate elastomer materials for your custom rubber seals.
PFAS stands for per- and polyfluoroalkyl substances, a large family of fluorinated chemicals that includes thousands of individual compounds. These substances are widely used in industrial materials because fluorine-carbon bonds provide exceptional properties such as:
However, PFAS is a broad category that includes two very different types of materials, which is where much of the confusion arises. This includes low molecular weight PFAS and polymeric PFAS.
These are smaller molecules typically used as polymerisation aids, surfactants, and processing additives. Examples of low molecular weight PFAS include PFOA, PFOS, PFHxS, and C9-C14 PFCAs. Because of their small molecular size, these compounds can be more environmentally mobile.
Polymeric PFAS are large molecular weight polymers used as engineering materials. Examples of polymeric PFAS include PTFE, FKM, FFKM, and TFM. These materials consist of long polymer chains and behave very differently from small-molecule PFAS.
During polymer manufacture, small molecule substances used in polymerisation are typically removed during processing and purification stages before the polymer reaches downstream manufacturers. These molecules are targeted for capture and disposal rather than being emitted. For example, manufacturers such as Chemours have reduced their FOC process emissions to air and water by 76% since 2018.
Understanding where PFAS chemicals appear in the supply chain helps explain the difference between polymer materials and polymerisation aids.
It’s important to note that most regulatory discussions focus on polymerisation aids used during production, rather than the finished polymer materials themselves.
Fluoropolymers are polymers that contain carbon-fluorine bonds in their molecular structure. These bonds provide unique performance characteristics that make them essential for demanding industrial environments. They have many key properties, which include:
In sealing technology, fluoropolymers commonly used are fluoroelastomers (FKM) and perfluoroelastomers (FFKM). These materials are used in applications where conventional elastomers would fail, including:
As fluoropolymers fall under the PFAS definition, their role in industrial supply chains is being closely evaluated within the current regulatory discussions.
One of the most common questions from engineers is whether fluoropolymers contain residual PFAS substances such as PFOA.
To investigate this, TRP Polymer Solutions conducted third-party PFAS extraction testing on several of its fluoroelastomer materials. Testing was performed using EN ISO 23702-1:2023 with THF extraction, targeting a wide range of low Mw PFAS compounds, including:
Our results were as follows:
| Material | Measurement | Result |
| TRPlast® 260B | Not detected | Pass |
| TRPlast® 300B | Not detected | Pass |
| TRPlast® LT45 | Not detected | Pass |
| TRPlast® LT45G | Not detected | Pass |
| TRPlast® 330B | Not detected | Pass |
Across all tested materials, no low Mw PFAS compounds were detected above the laboratory reporting limits, demonstrating the effectiveness of TRP’s manufacturing and formulation processes.
| Chemical group | Reporting limit |
| PFOS and related substances | 1000 ppb (sum) |
| PFOS and its salts | 25 ppb (sum) |
| PFOA and its salts | 25 ppb (sum) |
| PFOA-related substances | 1000 ppb (sum) |
| PFHxS and its salts | 25 ppb (sum) |
| PFHxS-related substances | 1000 ppb (sum) |
| C9–C14 PFCAs and their salts | 25 ppb (sum) |
| C9–C14 PFCAs related substances | 260 ppb (sum) |
| PFHxA and its salts | 25 ppb |
| PFHxA-related substances | 1000 ppb (sum) |
These results confirm that the tested TRP rubber materials contain no detectable residual PFAS substances above laboratory reporting limits. Therefore, when you purchase a TRPlast® O-ring, it does not contain the low Mw PFAS substances noted above. Please see our whitepaper on residual PFOA and PFAS testing of FFKM sealing materials for more information.
More materials were tested, so please contact us if you require further information on this aspect.
The European Chemicals Agency (ECHA) is currently evaluating a proposal to restrict PFAS under the REACH regulatory framework. This proposal has generated significant discussion across industries that rely on high-performance fluoropolymers.
Updated discussions in 2025 introduced additional application-specific derogations, covering sectors such as:
These exemptions recognise the critical role that fluoropolymers have in modern industrial systems and the lack of viable alternatives for many applications. Industry groups have also proposed exemptions for fluoropolymers themselves, given their large molecular size and low environmental mobility relative to smaller PFAS compounds.
As the regulatory landscape evolves, many manufacturers are exploring ways to reduce or eliminate fluorinated surfactants used during polymer production.
TRP Polymer Solutions formulates many of its elastomer materials in-house, allowing us close control over raw materials and processing methods. Where practical, fluorosurfactants are removed from the manufacturing process and are not intentionally added to elastomer compounds.
We have also developed fluorosurfactant-free FFKM materials, including the NFS75B compound. The compression set performance can be seen below:
These materials aim to preserve the performance expected from TRPlast® perfluoroelastomers while reducing the presence of small-chain fluorinated surfactants during manufacture.
Development work in this area continues, and TRP is actively working with customers to evaluate these materials in demanding sealing applications.
For engineers working in highly regulated industries, PFAS legislation adds another factor to consider when selecting materials. Key common questions are:
TRP FFKM materials do not contain PFAS surfactants. Some FKM formulations may vary depending on material type. TRP are currently updating the material datasheets to provide information on whether a material is manufactured with or without fluorosurfactants.
In the entire TRPlast® range, testing shows no detectable PFOA or related low Mw PFAS substances.
For FFKMs; alternative materials such as NFS75B are available where fluorosurfactant-free production is required. Some FFKMs are also already using fluorosurfactant-free technology, and we are updating our datasheets to clarify this. But technically, all TRPlast® articles are fluorosurfactant-free.
For FKMs; most grades are manufactured without fluorosurfactants. However, some grades are currently being reformulated to remove fluorosurfactants from the manufacturing process. We are creating new datasheets to clarify this.
Current materials remain available while TRP continues to monitor regulatory developments.
PFAS regulation will continue to evolve as regulators balance environmental protection with the need for high-performance materials in critical technologies. For demanding sealing applications, fluoropolymers remain essential materials as a result of their unique chemical resistance and durability.
By combining in-house formulation expertise, independent testing and ongoing development of fluorosurfactant-free compounds, TRP Polymer Solutions is helping customers prepare for future regulatory changes while maintaining the performance required for critical sealing systems.
At TRP Polymer Solutions, we are committed to providing custom rubber moulding solutions that meet the needs of both today and tomorrow. We pride ourselves on our ability to quickly adapt to regulatory changes, meaning that you can rely on our sealing solutions to not only offer dependability and resilience, but also full compliance with REACH.
If you’d like to find out more about our services and our fluorosurfactant-free custom rubber seals, custom rubber gaskets, and rubber diaphragms, contact us today, and we can discuss your most suitable choices in further depth.
20 May 2026 • 
8 min read
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FFKM, or perfluoroelastomers, are a group of elastomers that are used across a wide range of industries.
May 20, 2026 • 7 min read
FFKM, or perfluoroelastomers, are a group of elastomers that are used across a wide range of industries.
May 20, 2026 • 7 min read
Read our FFKM brochure in further detail to understand how TRP delivers outstanding sealing solutions for the most severe of chemical and high-temperature applications.
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