Fluoroelastomers – performance and responsibility

May 2022

Fluoroelastomers such as FKM and FFKM have been used for decades because of their high chemical and thermal resistance. These properties are significant advantages compared with polymers such as EPDM, NBR and HNBR – at least as long as the components made of these materials are in service.

However, at the end of service life, this high resistance can turn into a potential problem. If waste from the rubber component is not treated correctly, per- and polyfluoroalkyl substances (PFAS) can end in the environment. This group of organic chemicals is estimated to include more than 10,000 substances – and the influence of these chemicals is not all known. Due to the high chemical stability, such substances will accumulate and eventually cause health and environmental issues.

This is not new. Since 2009, certain groups of PFAS have been regulated globally under the Stockholm Convention, and later more groups have been added. In addition, ECHA – the European Chemicals Agency – has decided to regulate additional groups under the framework of REACH. A broad restriction proposal for all PFAS was published early 2023 by five European states and is also included in the European Commission’s Restriction Roadmap providing a priority list of chemicals suggested to be restricted.

At AVK GUMMI, we welcome these initiatives, but at the same time we make sure to monitor the development carefully in order to prepare for any changes that might influence our formulations.

Based on the restriction proposal, it seems that PFAS will be banned from 2027 for most applications, while food applications can continue until 2032 if fluorosurfactants are not used in the production of polymer. For AVK GUMMI, however, it is important to stay at the forefront of new legislation and thereby enable you to continue to provide the best solution to the market.

A few examples:

Improved chemical resistance of FKM for food contact

Going from Bisphenol AF cured to peroxide cured FKM and at the same time offering better chemical resistance allows for longer service life, hence less waste.

Extensive development, test and documentation, both in terms of performance and compliance, has led to a new range of high performance FKM for food and healthcare.

Although Bisphenol AF has been permitted for use – also in food contact materials – and for now will continue to be accepted in the EU in limited amounts, we have decided to phase out this substance for the benefit of consumer safety and the environment.

Tailormade FFKM

FFKM is renowned for its extreme chemical resistance. This is achieved by a very high degree of fluorination. Inherently, lack of degradation is even bigger.

When FFKM is requested, it is normally because very aggressive chemicals have to be handled. We have designed a concept by which different chemicals can be handled by different FFKM, FEPM and FKM grades, allowing for a tailormade solution. Not only will this provide an optimum performance solution; it will also allow for a balanced level of fluorination. Finally, this approach allows for cost optimised solutions, bearing in mind that the cost of FFKM is by the magnitude of 100 times that of FKM.  

Replacement of FKM?

Will fluoroelastomers be banned some time in future? There are many indications that this is very likely to happen. If it happens, the stakeholders in the entire value chain from ingredients, through elastomer compounds, gaskets, valves, process lines to filling- and packaging lines will have to adapt.

This could for instance be through a shift towards other elastomers, such as EPDM for low fat and some chemical applications or HNBR for fuel, knowing that there will be pros and cons in every change.

Less performance being a natural consequence of improved compliance has to be acknowledged. Rather than seeing this as a burden, we take the challenge and create the best solutions available and appreciate the improvements on consumer safety and sustainability.

Less performance in terms of chemical or thermal resistance should not only be mitigated by new ingredients and formulations, but also through clever re-engineering of rubber components, allowing for thermal expansion or swelling by means of reduced volume and contact area.

End-of-life handling of elastomeric waste

Situated in Denmark, AVK GUMMI benefits from a well-regulated system for handling waste. All of our elastomeric waste is declared and combusted, utilising the energy to produce electricity and domestic heating.