Karen McIntyre, editor01.19.24
As the EU and the U.S. Environmental Protection Agency (EPA) bring in further regulations to restrict the use of Per- and polyfluoroalkyl substances (PFAS), the nonwovens industry will face significant challenges. The ubiquity of PFAS means these changes will affect industries across the board, from construction to filtration, from medical to food and beverage. The nonwovens sector embraces innovation and environmental and social responsibility perhaps more than any other industry.
NIRI, world-leaders in nonwoven and textile product development and R&D, has produced a new white paper outlining the issues, and exploring potential solutions to help customers maintain a competitive edge while addressing the business-critical aspects of sustainability and social responsibility. The white paper offers insights into how new material science and fibre innovation, coupled with pragmatic product design decisions, can reduce dependency on PFAS or eliminate it altogether, without compromising performance requirements.
Dr Ross Ward, Chief Commercial Officer at NIRI, offers thoughts on issues facing the sector, based on the perspective of a range of experts at NIRI.
What is driving efforts among nonwovens producers and users of nonwovens to reduce and/or restrict the use of PFAS in their products?
Regulatory changes and the public perception of environmental and health hazards are the two key drivers behind the demand for nonwovens producers and users to limit or, where feasible, eliminate PFAS from their products. Ultimately, both regulators and the general public’s concerns are based on the continued accumulation of PFAS, also known as ‘forever chemicals’, contaminating soil, ground, and surface water, with the associated concerns over the impact on human health. There is increasing substantive evidence of links between exposure to PFAS and diseases of the kidney, liver, bowel, and thyroid, including cancers, with additional links to acute health conditions such as high cholesterol, and negative effects on hormone regulation and reduced fertility.
With one of the strongest single chemical bonds, the carbon fluorine bond has nearly double the bond strength of a carbon-carbon bond, meaning that chemicals resist natural, chemical, biological, and microbial degradation. PFAS contain multiple carbon-fluorine bonds (C-F bonds), so even where one bond is broken, several others may persist. Given that PFAS can easily enter the environment and be transported across hundreds of miles from their source during production and usage, decontamination can be both difficult and costly. Together with the health issues associated with PFAS, this has led to the regulatory landscape nonwovens producers now face, covering the manufacture, use, and the environmental release of PFAS.
While there are existing regulations, including the International Stockholm Convention of persistent organic pollutants updates from 2009 onwards, where we are in 2024 there are crucial, imminent dates on the regulatory horizon. Next year, the European Chemical Agency’s recommendation on the restriction of PFAS will become part of REACH regulations, meaning a total ban on the use of many PFAS above a threshold quantity after the transition period. In the US, the EPA is working to limit human and environmental exposure to PFAS by removing an exemption permitting organisations to avoid reporting the release of small quantities of PFAS to the Toxic Release Inventory. It has also proposed a rule to prevent the manufacture, processing, or use of at least three hundred dormant PFAS chemicals that have not been made or used for many years without a complete review and risk assessment by the EPA. Given this regulatory timeline and increased public awareness of the environmental and health impact of PFAS leakage, nonwovens producers and commercial users are, understandably, looking to alternatives and to mitigating the effects of the demand to reduce or eliminate PFAS.
How are most producers going about this? Are they finding success?
Two options to reduce the reliance on PFAS that we are seeing are the search for alternative chemistries and - a short-term approach – a concentration of existing stocks of PFAS into prioritised product lines. For this second option, where stocks of PFAS are already considered limited, some companies are restricting usage and focusing on a smaller number of products to eke out their available PFAS stocks. But this obviously isn’t a commercially sustainable option, as it leaves products out of specification or underperforming, and could mean companies are losing the return on original investment in product development where lower priority products aren’t being manufactured and sold.
Finding a direct replacement for PFAS through alternative chemistries presents significant technical challenges, particularly given the ubiquity of PFAS and their relatively low cost. For water repellency, there is some success currently in the replacement of PFAS with fluorine-free water repellents. Silicones / siloxanes, silanes, paraffin waxes / hydrocarbons, and fatty acid derivatives are all alternatives to PFAS for water repellency. Yet these are not all hazard-free, as polydimethylsiloxane (PDMS or dimethicone) can contain cyclic siloxane impurities that are persistent and bioaccumulative. Some silanes are persistent, mobile, and toxic, while with paraffin waxes / hydrocarbons there is the aquatic chronic toxicity of C9-C14 isoparaffins.
Progress has been made in producing commercially available, or scalable PFAS-free formulations that have excellent performance levels, but mainly in relation to water repellence. Some major players have developed fluorine-free durable water repellents (hydrophobic treatments), with performance clothing brands adopting fluorine-free durable water repellents (DWR), for example utilising silicones, siloxanes, and paraffin waxes to provide water repellency for jackets and active wear, maintaining water resistance without the use of PFAS. Fatty acid derivatives are being used by some home furnishing brands, which offer some level of water and stain resistance as treatments for couches and carpets. Within the medical and hygiene sectors, for products such as surgical gowns or diapers, bio-based polymers are being explored as alternatives to provide liquid barrier properties, with bio-based coatings being tested for use in protective clothing for fluid resistance and breathability. For industrial and technical textiles, silanes and silicones are being utilised where industrial applications require water repellency, such as the automotive sector. And, in the construction industry, nonwoven geotextiles treated with silicone-based products are being used for water repellency and durability, without recourse to PFAS. And, in the food sector, as an alternative to PFAS in food packaging, wax-coated papers are now being used, which provide a degree of grease resistance while being more environmentally friendly.
However, despite these alternatives being investigated or used, oil repellency and stain resistance present much greater challenges than water repellence, given the low surface tension of oils. Industrial approaches based on biomimicry are more limited given that, in nature, fewer oleophobic surfaces exist than hydrophobic.
Why is this more important in nonwoven-based products than in other industries?
The sheer ubiquity of PFAS means that for many sectors, including geotextiles and water proofing, research into alternatives by those working in nonwovens is spearheading the development of novel solutions alongside the re-design of existing products.
The thermal and chemical stability of PFAS from their unique carbon-fluorine bond, together with their exceptional oil and water repellency, has made the performance capabilities of PFAS a critical component in applications where demands are most stringent – such as Chemical, Biological, Radiological and Nuclear (CBRN). But PFAS are found in numerous products where they may, arguably, be overperforming, such as for single use food packaging. And the same is true of many sectors where PFAS are currently prevalent. Looking at just one sector, for example, the construction industry relies heavily on a broad range of products with nonwoven elements, such as weatherproof membranes and tensile roofing; carpets and flooring; and for commercial and domestic products. Without concerted effort on the part of nonwoven specialists researching these product components, an enforced reduction in the reliance on PFAS presents major challenges for construction product manufacturers, contractors, specifiers, designers and architects.
It is imperative for nonwovens manufacturers to lead the way in reducing PFAS and developing alternative technologies. The performance challenges that industries face, especially in medical, filtration, hygiene, technical textiles, and converting sectors, demand immediate action. Derogations for the use of PFAS in medical devices are not only limited but also temporary, underscoring the urgent need for nonwoven solutions. The expertise of nonwoven specialists is not just beneficial but essential for addressing these critical issues and ensuring sustainable product performance now and in the future.
What have been the main challenges in achieving this?
There are significant challenges – not least the understandable commercial rationale behind the continued use of PFAS where this has been permitted, given their low cost. Add to this the range of hazards – noted above – around alternative chemistries as direct replacements for PFAS, and the challenges continue to mount. This is where nonwovens producers can really benefit from a pragmatic approach, looking beyond a surface solution: where product performance is provided by a PFA-based surface coating, considering the interaction of water, oils, and other contaminants within the nonwoven structure itself.
NIRI are already using this approach to help overcome the challenge of PFA replacement, working with customers to re-evaluate product design and performance requirements. For example, we are looking to exploit innovations in fibre science, and alternative nonwoven fabric constructions and membranes which, when assembled correctly – especially in laminated or layered fabric constructions – can reduce the need for PFAS. Using our prototype-scale meltblown, spunbound, electrospinning, airlaid, wetlaid, and carding facilities, we are exploring options for adding layers containing appropriate fibre blends to achieve the necessary balance between permeability and oil and water repellency.
What potential do these efforts have to ultimately influence product design or performance?
Arguably the most interesting aspect of the quest for alternatives to PFAS is the very lack of a singular, PFAS-free analogue chemistry which can replicate the same combination of properties, cost-effectively. This scenario obliges us to interrogate product specification and performance, whereby further environmental benefits are possible through a circular economy approach at the product design stage.
De-coupling the combined requirements for a product, rationalising the use of hydrophobic and oleophobic coatings, and reconsidering product specifications can help make headway in sourcing alternatives to PFAS. As we’ve already suggested, beyond a chemical substitution strategy the opportunity here is to re-evaluate a product’s design and consider how the engineering of other parts of the fibre or fabric system might contribute to bulk performance rather than relying completely on a chemical coating, additive, or membrane. At this re-design stage, we can ensure that new developments from such a product review are compatible with circular economy approaches, to mitigate concerns over ecotoxic chemical and plastic leakage into the environment, while considering plausible reuse and recycling strategies.
For the nonwovens sector as a whole, the shift from PFAS chemicals offers scope for a broader, large-scale review of standards and technical specifications, where products may be currently over-specified when considering their real-world usage. The impetus for such a major strategic project would require concerted effort from key industry players, working closely with regulatory bodies and legislators. While ambitious in scope and scale, this could be an integral aspect of the elimination of PFAS, globally.
How does NIRI suggest companies best go about reducing or restricting PFAS?
We believe that collaboration delivers the best results. Given the broad scope of sectors and products impacted by regulatory changes, harnessing the expertise of industry alongside R&D partners to accelerate innovation will be greatly assisted when performance is considered on a product-by-product basis. At NIRI, we believe in a pragmatic approach: the current use of PFAS may not even be necessary in cases where performance is over-specified, once real-word functionality is properly evaluated.
While there isn’t an easily available option to replace PFAS chemicals, replicating the same properties, there are opportunities to address over-specification and enhance corporate reputation with consumers. Where public awareness of the environmental impact of PFAS and the demand for more sustainable product offerings is only growing, those embracing their corporate and social responsibility – as demonstrated by a re-evaluation of product design which emphasises a responsible and circular approach to a product’s lifecycle – can capture greater market share and differentiate themselves from competitors. Tackling the PFAS issue is one of many sustainability challenges NIRI helps our customers to address, and companies worldwide rely on our industry-leading scientists and our prototyping and analytical capabilities to assist in the development of commercially viable products and the identification of new markets, accelerating innovation with world-class scientific expertise.
More information: enquiries@nonwovens-innovation.com; +44 (0)113 350 3829; www.nonwovens-innovation.com. Download the white paper here.
