An investigation into the presence of harmful chemicals in textile waste seeks to assess whether it is safe or not to recycle old clothes into new ones. Initial findings have found this risk to be low, but not negligible. It is a signal that further research is needed, along with a better understanding, and tracking, of chemical usage.

To meet growing demand for recycled cotton, denim mills have been reorganising their workflow to capture as much unused fibre and fabric as possible from their own operations. They supplement this limited resource, in a well-run factory, by working with collectors and recyclers of used clothing. The availability of mechanically recycled cotton has thus steadily increased, a positive evolution by any measure.

Brands and retailers need to keep this momentum going if they are to meet their goals to source more sustainable materials. This is what inspired Ikea and H&M Group to take a closer look at one of the lesser known facets of recycling: the presence of hazardous chemicals in materials intended for a second life. Launched in 2019, the research project was expanded in 2020 to include Gap, PVH and Bestseller, among a new set of industry partners. The findings will be used to create a databank that will be shared within the industry and with legislators.

The study’s first run examined three sets of textile waste made from cotton, wool and polyester, collected in Europe, the USA and Asia. Literally thousands of tests were conducted on the shredded material. For the most part, no regulated substances exceeded accepted limits based on the restricted substances list (RSL) of the Apparel and Footwear International RSL Management (AFIRM) group, a widely recognised resource. Within the 172 cotton samples, 99.97% were given a pass, and in 98.23% of the lot, no restricted substance was detected at all. Harmful chemicals were found to be above the accepted threshold in eight instances out of a total of 24,700 analyses. Polyester waste was similarly considered clean, as 99.3% of the 169 samples passed. For wool, while 98.5% of the 154 wool samples were considered safe, 216 tests found chemical content to be above accepted limits, and in 145 instances these were nonylphenol ethoxylates (NPEOs). “Although the overall fail rate was low, the failures were spread over many samples,” say Negin Farhadi, H&M’s project manager for recycled textiles, and Mirjam Luc, project leader for recycled textiles at IKEA of Sweden.

At first look, these findings can be considered reassuring. For the vast majority of samples, no restricted substance was detected and, when present, remained under accepted limits. The report confirms nonetheless that textile waste can be tainted by chemicals of concern. Formaldehyde showed up in many wool samples, and the APEO group of surfactants (covering NPEOs and OPEOs) were found across all three material categories. A common component of detergents, scouring or wetting agents, dye-dispersing agents and spinning oils, their enduring presence could be problematic. “Nonylphenol ethoxylates, or NPEs, pose no risk to consumers of apparel and footwear themselves, but they degrade into nonylphenol (NP) in wastewater systems and in the environment,” says AFIRM Group director Nathaniel Sponsler. NP is considered persistent in the aquatic environment, moderately bio-accumulative, and extremely toxic to aquatic organisms. Legislation around the world restricts the presence of APEOs in finished goods.

How and why they turn up is an open question. Their presence may not be intentional. The precise formulation of chemicals used in the textile and apparel industry is not always known. A harmless substance may become harmful in some conditions.  It is also possible that the textile waste comes from items of clothing made at a time when there were fewer restrictions.

An ever-evolving notion of safety

The evolution of chemicals regulations policies is one of the issues this study brings to light. “The number of restrictions for chemicals has grown from only one in 2014 to over 5,000 in 2022,” said Carole Mislin, Archroma’s head of global product stewardship, at a conference organised by the French National Institute for Industrial Environment and Risks (Ineris), on hazardous chemicals in textiles.

The definition of what is safe keeps changing, says Mr Sponsler. “A substance that was perfectly legal a few years ago may become illegal at a later date, or the residual amount allowed in a product may be substantially decreased by new regulation. This means that a material manufactured today may face stricter rules later on that would not allow its use in new products.”

The EU is in the process of potentially adding over 1,000 new restrictions, of which 20% are thought to be relevant to the apparel and footwear industries, says Mr Sponsler. “Some of the new guidelines bring allowed levels down to parts per billion (ppb).” These difficult to detect trace amounts could have an impact on the recyclability of used textiles.

As new data emerges on the presence of hazardous chemicals in used textiles, new questions will emerge. “It may be possible to wash out some of the unwanted, or now illegal, chemicals. But that may require a lot of water, energy and additional chemicals, and may not be sustainable,” says Mr Sponsler. This situation raises another set of questions. “Should specific rules be set for recycled content? A separate RSL could be developed for recycled materials, but would it meet basic market requirements?” he asks.

Textile waste is not the only source of concern, as polyester recycled from post-consumer PET bottles has been found to contain trace amounts of bisphenol A (BPA). “All possible sources are being investigated, but early indications are that it could come from polycarbonate bottles mixed in with PET plastics,” says Mr Sponsler. If that were the case, it would be necessary to implement finer sorting processes to keep polycarbonate bottles out of PET feedstock or treat the solution to filter out the BPA. “We are learning as we go,” he says.

Chemsec, like AFIRM, was consulted by the Ikea and H&M research team. “Chemsec reviewed the findings, and we commend it as a great example of collaboration for good. There is a huge lack of information on recycled textiles, and this is an attempt to fill that gap,” says Chemsec senior policy advisor Theresa Kjell. The environmental NGO based in Sweden advocates for the removal of hazardous substances from consumer goods.

“I was surprised that the results were so good for cotton. This issue of chemicals in waste textiles is not problem free, but slightly better than expected,” she says. Azo dyes, for instance, did not show up. “This confirms that regulations have an impact.”

Tracing chemicals 

The new data revealed by H&M and Ikea sends a clear signal to the industry that more information is needed on the chemicals it uses. In addition to providing recyclers with a go ahead to recycle identified waste, it could also increase the value of used textiles, says Ms Kjell.

Currently, most traceability systems focus on keeping track of fibres throughout the supply chain. Few cover chemicals. 
Toxnot, a company founded in 2016 and based in Fort Collins, Colorado, includes data on chemicals as part of its sustainability compliance services. Its software platform creates material passports for textiles used in apparel, furniture and architecture. “Brands try to do good, and we are working with them to achieve this. But the industry does not have the tools to screen chemicals used to make their products. We are filling a gap,” says Toxnot CEO and founder Peter Girard.

In circularity, he says, there has been a lot of focus on recycling and not much on chemistry. To support the addition of sensitive data to its traceability platform, Toxnot allows companies to make ‘blind’ information they do not want to share if they feel this is necessary to protect intellectual property. They can decide what data will be made available to whom. Recyclers may be given access to information on chemicals that would otherwise be withheld.

Are used textiles and clothes toxic? 

For those promoting circular solutions and mechanical recycling of textile waste, the presence of hazardous chemicals is, unsurprisingly, a cause for concern. But so are the escalating quantities of unwanted clothes, which have likely been worn and washed for years before being discarded. “This is clearly an important issue. Yet, we need to recognise that we collectively produce a tremendous amount of post-consumer material. In my mind, it is better to recycle it than send it to landfill,” says Accelerating Circularity founder Karla Magruder. This point of view may well be shared by the many companies specialising in the reuse, resale or rental of second-hand clothes. These are not known to be subject to chemical testing or to any specific standards.

“The Ikea and H&M study shows that the risk profile is not so high for post-consumer cotton textile waste as may have been originally thought,” says Helene Smits, chief sustainability officer for Recover. A global producer of mechanically recycled cotton, founded by 70-year-old Spanish spinner Hilaturas Ferré, Recover was spun off as an independent entity and acquired by US private equity firm Story3 in late 2020.

The company recycles cotton textile waste into fibres that it sells to spinners, who most often blend the recycled material with other sustainable fibres. “Our products are all certified Oekotex 100 class 1. We test them at 100% concentration level, meaning 100% recycled content, to guarantee they do not exceed accepted levels of detection,” says Ms Smits.

Recover currently processes post-industrial waste for some 95% of its business, which Ms Smits says is expected to be REACH compliant, whether produced in Europe or elsewhere. The remaining 5% of its production is cotton recycled from post-consumer jeans.

Whatever the source of the material Recover recycles, each bale will have highly variable content. To uphold its certification, the company tests random samples twice monthly, says Ms Smits. It now tests every lot for specific chemicals on top of that. For post-consumer fibres, it takes samples from multiple places in one lot and mixes them to get a good average sample. “If we sampled from a single area, we could be lucky or unlucky,” she says. This raises the question of whether different testing protocols should be applied to post-consumer waste, which is by nature heterogenous. “We need standards that ensure safety, and that allow us to keep costs manageable,” she says.

Can chemicals be stripped out? 

Some point to chemical recycling as a possible solution to remove toxic chemicals in used textiles, as it dissolves the feedstock and can then filter out problematic substances. But the Technological Readiness Level (TRL) of chemical recycling processes is low, from three to six, on a scale of nine, says Jeanne Meillier, project manager at French material innovation and sustainability cluster Euramaterials. “Mechanical recycling is much more advanced, and has greater economic potential,” she says. She also notes that mattress recyclers sanitise used goods to neutralise any pollutants before recycling them.

Various methods to strip away dyes from waste textiles, using supercritical carbon dioxide or ozone, could be an option for removing unwanted substances, and increasing the value of recycled feedstock. But these, says Ms Meillier, can be energy intensive. Lei Yao, director of product development at Hong Kong-based textile research centre (HKRITA), says that supercritical water could be a solution. “It is a very powerful and efficient technology, but there are lower-cost methods,” she says.

HKRITA has recently finalised a study on the decolouring of polyester textiles. It has found that a combination of high temperature, high pressure and water “makes the polyester fibre swell and release its colour,” says Lei Yao. Activated carbon is then used to absorb the discharged dyes. “This process does not affect fibre quality, and it is not very expensive,” she says. Though it sounds simple enough, Ms Yao admits there are some challenges. “The system works well on some dyes and not on others. We need more comprehensive studies of different dye families.”

This circles the issue back to the initial question that the H&M and Ikea project was looking to answer: what chemicals remain lurking in a random bale of discarded, no longer wearable clothes? The chemical experts consulted tend to insist that legal limits are legal limits and, to be put onto the market, any recycled product must be guaranteed to be safe. 
But they also intimate that as regulations become ever more stringent, it may become near impossible to find feedstock suitable for mechanical recycling.  “It will be challenging to tackle the issue of legacy chemicals, but developing closed waste streams is one way to decrease the problem, as open ones could be too contaminated,” says Theresa Kjell, at Chemsec.

For those who favour mechanical recycling, as does Karla Magruder, at Accelerating Circularity, it is commercially viable and should be encouraged. “It will support the development of sorting and pre-processing technologies. A recycler should be able to say, I need this and don’t want that, and be able to place an order that meets its standards,” she says.

The two camps agree on one matter: hazardous chemicals should be phased out from the start. This would take care of the problem of having to remove them later.

A collaborative study led by H&M and Ikea on the presence of harmful chemicals in textile waste has revived an issue that some recyclers have been flagging for years. 
Photo: IKEA Sweden

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