The textile industry has long relied on various additives to enhance the properties of fabrics, making them more durable, resistant to stains, and even antimicrobial. These additives include dyes, coatings, flame retardants, and water-repellent finishes. While they offer significant functional benefits, they pose a serious challenge when it comes to recycling textiles. Since many of these additives are chemically bonded to fibres, they make the separation and recovery of pure materials incredibly difficult.

With the increasing global emphasis on sustainability, textile recycling has become a crucial component of waste reduction. However, the presence of synthetic chemicals complicates the recycling process, making it less efficient and often resulting in downcycled or non-recyclable waste. Therefore, consumers and environmental organisations are pushing for cleaner alternatives, but the challenge remains in balancing performance, cost, and sustainability. If the textile industry does not take immediate steps to address this issue, the accumulation of non-recyclable fabrics will continue to pose significant environmental threats. Understanding how these additives impact recycling is essential to creating a circular textile economy that benefits both businesses and the planet.

Types of Textile Additives
Textile additives can be broadly classified into chemical-based additives and sustainable alternatives. These additives are used to improve various properties, such as colour fastness, water resistance, fire retardancy, and antimicrobial protection. However, their impact on the environment varies significantly

Chemical-Based Additives
Chemical-based additives have been widely used in the industry due to their effectiveness, but they often come with environmental concerns. For example, formaldehyde is commonly used to give fabrics wrinkle-resistant properties, but it is also linked to health hazards such as respiratory issues. Similarly, phthalates, which are found in synthetic coatings and flexible plastics, have been associated with environmental toxicity. Another widely used group of additives is PFAS (Per- and Polyfluoroalkyl Substances), which make textiles water and stain-resistant but are highly persistent in the environment, earning them the nickname ‘forever chemicals’.

Other examples include azo dyes, which can release carcinogenic amines under certain conditions, and brominated flame retardants, which are highly toxic and have been found to accumulate in human tissues. These chemical additives, while effective in improving fabric properties, create significant problems during the recycling process.

Sustainable Additives
In contrast, the industry is now exploring more sustainable additives that minimise harm to the environment. Bio-based finishes, such as those derived from plant oils or proteins, are gaining popularity as they provide the same benefits without lasting chemical residues. Enzymatic treatments are also being developed, where biological catalysts modify fabric properties without leaving harmful pollutants behind.

For example, chitosan, derived from crustacean shells, has shown promise as an antimicrobial alternative to synthetic chemicals. Natural waxes and vegetable-based water repellents are being developed as replacements for PFAS. These alternatives show promise in making textiles more recyclable while maintaining their functional properties.

Impact on Textile Recycling

Difficulty in Separating Additives from Fibres
One of the biggest hurdles in textile recycling is the difficulty in separating additives from fibres. Many traditional recycling methods, especially mechanical recycling, involve shredding fabrics into fibres to be re-spun into new textiles. However, the additives remain in these recycled fibres, often affecting their quality and usability. This is why recycled textiles sometimes have compromised durability, colour consistency, or texture.

In chemical recycling, where textiles are broken down into their base polymers, the presence of additives complicates the purification process. Many additives do not degrade easily, leading to contamination of the recycled materials, reducing their usability for high-quality applications.

Environmental Concerns
Chemical-based additives also contribute significantly to environmental pollution. When textiles containing synthetic coatings are washed, they can release microplastics into waterways, which then enter marine ecosystems and even the food chain. Additionally, textiles treated with toxic dyes and coatings can release hazardous emissions when incinerated, leading to air pollution.

Moreover, some textile additives, such as heavy metal-based dyes and flame retardants, persist in the environment for decades, accumulating in soil and water bodies. The presence of toxic compounds in landfills and wastewater poses a long-term environmental hazard, making it crucial to rethink how additives are used in the textile industry.

Challenges in Mechanical vs. Chemical Recycling
While mechanical recycling is the most widely used method, it struggles to remove harmful chemicals from fibres, leading to lower-quality recycled materials. On the other hand, chemical recycling offers a more sophisticated approach by breaking textiles down into their base polymers, but the presence of additives makes the process costly and complex. Solvent-based recycling methods are emerging, but they are still in early development and are not yet widely implemented.

Current Solutions and Innovations

Additive-Free Textile Production
To combat these challenges, researchers and manufacturers are working towards additive-free textile production. Companies are exploring innovative fabric blends that naturally possess the desired properties, reducing reliance on chemical treatments. For instance, hemp and wool have natural antimicrobial properties, eliminating the need for additional treatments. Similarly, brands are now experimenting with bioengineered materials, such as spider silk-inspired fibres, which offer superior strength and elasticity without synthetic additives.

Biodegradable and Non-Toxic Alternatives
Another promising avenue is the development of biodegradable and non-toxic alternatives. Natural dyes made from plant extracts are replacing synthetic dyes, helping reduce chemical waste. Chitosan-based antimicrobial finishes, derived from seafood waste, are emerging as sustainable options that provide the same protective benefits as conventional chemicals without causing harm to the environment.

Advanced Recycling Technologies
Advanced recycling technologies are also being explored. Enzymatic degradation, for instance, uses specific enzymes to break down textile additives without affecting the fibres themselves. This method holds great promise in making recycling more efficient. Similarly, solvent-based separation techniques are being tested, which involve dissolving and extracting harmful additives before recycling the fibres. While these processes are still in their early stages, they represent significant strides towards a circular textile economy.

Future Outlook and Sustainable Practices

Regulations on Textile Additives
Looking ahead, stricter regulations on textile additives will play a crucial role in ensuring a more sustainable industry. Several governments and environmental organisations are pushing for restrictions on harmful chemicals, forcing manufacturers to seek safer alternatives. The European Union, for example, has been leading initiatives to limit the use of toxic chemicals in textiles, and similar regulations are being discussed globally. Brands that fail to adapt may face heavy fines or bans on their products in environmentally conscious markets.

Need for Industry-Wide Sustainable Approaches
The textile industry as a whole must adopt sustainable approaches to remain viable in the long run. This means not only focusing on greener production methods but also improving recycling infrastructure to handle textiles with fewer harmful additives. Industry-wide collaboration is key, with textile producers, recyclers, and policymakers working together to create solutions that balance performance with sustainability.

Circular Economy Models for Textiles
A shift towards circular economy models in textiles is perhaps the most promising strategy. This involves designing textiles for recyclability from the very beginning, choosing safer additives, and investing in closed-loop recycling technologies. Companies that prioritise sustainability now will not only reduce their environmental footprint but also gain a competitive edge in an increasingly eco-conscious market. Some brands are also adopting take-back programmes, where customers can return used garments for proper recycling, ensuring fewer textiles end up in landfills.