US-based manufacturer Greene Tweed has launched a PFAS-free sealing material for hydrogen and carbon capture, utilisation and storage (CCUS) applications, as manufacturers face mounting pressure to reduce their reliance on so-called ‘forever chemicals’.
The development is an example of efforts to find alternatives to fluorinated materials used in industrial equipment, where chemical resistance, pressure tolerance and low-temperature performance remain critical requirements.
Greene Tweed’s product, the EPM 893, is a sealing material designed to meet the challenging conditions often associated with hydrogen and CCUS systems while eliminating PFAS.
“EPM 893 was developed to reduce the tradeoffs engineers typically face in these environments,” said Arturo Flores, Product Manager, Sealing Systems.
The compound is designed to operate continuously at temperatures down to -60°C, with a typical service temperature range of -67°C to 150°C.
Greene Tweed said it has also demonstrated resistance to rapid gas decompression in hydrogen and supercritical carbon dioxide (CO2) environments at pressures of up to 200 bar.
The material has been tested for compatibility with 100% hydrogen, supercritical CO2, oxygen and amine-based carbon capture processes.
Greene-Tweed’s O-ring style PFAS-free seal technology ©Greene-Tweed
It is available in O-ring, GT Ring and custom-moulded formats for applications including valves, instrumentation, compressors and pipeline infrastructure, according to the company.
“Companies building hydrogen and CCUS infrastructure need partners who can grow with them from production and capture through transport and storage,” said Charles Burke, General Manager, Sealing Systems and Seal-Connect.
The challenge of finding alternatives
The launch comes as the industrial gas industry faces questions over the future use of PFAS – or per- and polyfluoroalkyl substances. They comprise a broad family of synthetic chemicals valued for their resistance to heat, chemicals and degradation, but which have attracted regulatory scrutiny because of their persistence in the environment.
Around 15,000 PFAS substances are known to toxicologists, according to comments made by Emily Foster, Technical Manager at the British Compressed Gases Association, at the organisation’s conference in May.
Foster described PFAS as “one of the biggest concerns that we’re facing at the moment”, pointing to the strength of the carbon-fluorine bonds that underpin their durability.
“They don’t degrade easily and often end up miles away from the source,” she said.
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However, those same properties have made PFAS materials difficult to replace across a range of industrial applications. Foster identified their use in hydrogen systems, cryogenics, gaskets, hoses, lubricants and fire suppression equipment, warning that suitable alternatives may not yet exist for some applications.
“The reason why PFAS are so good is because they are chemical resistant, pressure resistant and temperature resistant,” she said. “But that is also what makes them persistent.”
The challenge applies especially to hydrogen infrastructure, where materials must withstand demanding operating conditions while maintaining system integrity and preventing leakage.
A June 2025 gasworld on PFAS and industrial gases also identified seals, gaskets, lubricants and membranes as potential areas of exposure for the sector.
The report highlighted the use of fluoropolymer-based membranes in proton exchange membrane electrolysers and hydrogen fuel cells, alongside PFAS-containing materials in gas-handling equipment.
It warned that restrictions could have implications for critical equipment and technologies, particularly where suitable substitutes have not been established.
In medical oxygen systems, for example, the report examined the use of PFAS variants in oxygen-compatible lubricants for valves and regulators. These materials play an important role in equipment safety, given the heightened flammability risks associated with oxygen service.
The report assigned the industrial gas and equipment sector a PFAS risk score of 4/5, citing uncertainty around regulation, potential supply chain disruption and the availability and safety of alternative materials.
A survey conducted at the European Specialty Gas Summit in 2025 found that 64% of respondents were either very or extremely concerned about the issue.
Regulatory uncertainty
The regulatory response also presents challenges for manufacturers operating across international markets. While the UK has set out plans to address PFAS through an evidence-based approach, the EU is pursuing broader restrictions on the substances.
Foster said industry had argued for regulation that takes account of the specific applications and risks associated with individual materials, rather than a blanket approach.
“We have always been arguing that we need an evidence-based regulation, rather than just banning and restricting all of these materials,” she said.
She also warned that globally integrated supply chains could leave companies exposed to restrictions in other markets, even where domestic regulation takes a different approach.
“Trade is very integrated. Supply chains are very complex,” she said.
The economic stakes are also substantial. ChemSec estimates the global PFAS market is worth $25bn to $30bn, while the European Commission has put the societal, environmental and health costs associated with the chemicals in Europe at €440bn ($490bn).
The global PFAS treatment market is forecast to reach $3bn in 2026, according to Grand View Research, while the UK Government has cited estimates that the EU market for PFAS-free alternatives could be worth $14.9bn annually by 2040.
