The eternal issue - unresolved for the time being

The term PFAS refers to perfluorinated or polyfluorinated alkyl substances. These are hydrocarbon chains in which hydrogen atoms are completely or partially replaced by fluorine atoms. The group of substances comprises more than 10,000 individual substances, the exact number is not known. PFAS have no natural origin, but have been produced exclusively artificially since 1950. The substances are used in a wide range of industrial applications and consumer products.

Exceptionally high chemical stability

What all PFAS have in common is their exceptionally high chemical stability. Natural degradation is slowed down, is incomplete or not possible at all and consequently leads to a worldwide spread and accumulation of the various compounds. The accumulation of PFAS in nature, in animals or in humans has negative ecological and health effects and is the subject of numerous intensive studies.

The role of PFAS in lubricants

PFAS are found in lubricants mainly in two forms: Perfluoropolyethers (PFPE) and polytetrafluoroethylene (PTFE, Teflon). Polyfluoropolyethers are liquids that are used as lubricating oils or thickened as lubricating greases. They are typically used in high-temperature and vacuum applications. Due to their high stability, PFPE oils and greases are predestined for lifetime lubrication. They are non-flammable, resistant to radiation and have universal material compatibility, especially with plastics. Combinations of highly volatile and low-volatility PFPE oils are used to produce extremely thin lubricating films for electrical contacts. Overall, PFPE greases and oils are expensive but extremely efficient lubricants. Their properties are not currently represented by any other lubricant group.

Teflon reduces frictional resistance

PTFE is used as a micronized powder or as a dispersion in the production of lubricants. In higher concentrations it is used as a thickener, in lower concentrations as a lubricant additive and/or auxiliary thickener. As a thickener, PTFE is found in PFPE oils or in silicone oils. As a lubricant additive, PTFE is used in many conventional lubricants. PTFE significantly improves the lubricating properties in boundary and mixed friction conditions, it reduces frictional resistance, has noise and vibration damping properties and reduces the so-called stick-slip effect. The dirt-repellent effect of PTFE in lubricants is controversial. Overall, PTFE is a very effective lubricant additive.

What does PFAS regulation look like?

The legal regulation of PFAS is inconsistent internationally and is subject to ongoing discussions and changes. In principle, it is to be expected that regulatory pressure and thus the number and variety of legal requirements will increase worldwide.

A few PFAS are already regulated by European legislation (REACH, SVHC) or by international agreements (Stockholm Convention, POP Convention).

In some US states, there are various ban initiatives that are currently mainly concerned with end consumer applications, such as packaging, cooking appliances and textiles. Further bans are planned until 2028; an expansion is likely.

The large group of all PFAS compounds is to be regulated in future by an EU legislative initiative. The corresponding restriction proposal was presented by several European countries in April 2020 and subsequently discussed with stakeholders.

Restriction proposal provides for an almost complete ban

In March 2023, the European Chemicals Agency published the preliminary restriction proposal, which provides for a further six months for consultations with the affected stakeholders. Once this period has expired and a decision has been made by the European bodies, the regulation is expected to enter into force in 2025/2026. The restriction proposal provides for an almost complete traffic ban with three transitional periods: 18 months, 6.5 years and 13.5 years. The following deadlines are mentioned for PFAS in lubricants:

Obligation to report PFPE

Due to the high costs, PFPE lubricants are only used when there is no technical alternative. The restriction proposal takes up this argument and proposes a transitional period of 13.5 years for critical applications ("harsh environments" and "safe functioning and safety of equipment"). However, the exemption is not a "carte blanche": Manufacturers and distributors must report products, applications and quantities. Manufacturers, distributors and end users must justify the use of these products as part of a management plan, define conditions of use and guarantee safe disposal.

PTFE probably not worthy of an exception

The use of PTFE as a thickener for PFPE oils tends to be assigned to critical applications; the assessment is less clear for silicone oils.
The use of PTFE as a lubricant additive is assessed in a more differentiated manner. The restriction proposal differentiates between the applications. Some applications (e.g. bicycle chain oils containing PTFE, low-noise lubricants in motor vehicles) are not considered "worthy of exception". For these products and in these applications, the restriction proposal provides for a transitional period of only 18 months. It can be assumed that the use of PTFE as a lubricant additive will be considered and regulated under this question (critical/non-critical application).

In the non-industrial sector, PTFE powder may also be regulated by new provisions in the area of microplastics. As various environmental and nature conservation associations are also taking part in the consultations alongside the industry, further measures or a tightening of the conditions for the use of PFAS are certainly possible. The focus is particularly on so-called "environmentally open" applications.

Effects on the market

The upcoming PFAS regulations are also leading to reactions on the supplier side. In anticipation of a shrinking market for PFAS, the first companies are reducing their business activities or withdrawing from the market (e.g. 3M). As a feedback effect, there will most likely be restrictions in the availability and variety of raw materials; the further development of the price level of PFAS is uncertain.

What does this mean for specific lubricant applications?

First of all, users should check their lubricants for PFAS - the suppliers can help here. For PFPE oils and PFPE greases (also PTFE-thickened), a transition period of 13.5 years is to be expected - as things stand today - if the application is critical. As PFPE lubricants are often used in special applications, this condition is probably often fulfilled. The downside: Special applications or application conditions require increased or longer development efforts for an equivalent PFAS-free replacement product or a modified design.

For lubricants that contain PTFE as an additive, the conditions of use will determine the length of the transition period. For non-critical applications or if the market already offers PTFE-free alternatives, the "worst case" with the short transition period of 18 months could occur. For this combination, it is currently most urgent to think about alternative products or product strategies.

Massive technical impact on lubricants

The restriction proposal will have a massive technical impact on the performance of lubricants. A similar situation applies to plastic materials containing fluorine that are used as construction elements. Against this background, it should be noted in all activities that the restriction proposal is currently in the consultation process and then still has to go through the European legislative procedure - changes are therefore guaranteed.

Parallel to closely monitoring the legal changes, Chemie-Technik is already actively working on a "Plan B" in research and development with concrete results - alternative raw materials and thickener systems are being investigated and PFAS-free alternative products are being tested. There are promising alternatives to PTFE, especially when it comes to solid lubricants. Under certain circumstances, silicone oils can also be thickened without solids without losing their approval for the food industry.