Natural Fibers
Natural textiles like cotton and wool are often viewed as environmentally friendly alternatives to their synthetic counterparts. However, natural textiles are not always as natural as they seem.
Plant- and animal-based fabrics have an array of benefits, like breathability, the ability to biodegrade, and their non-plastic makeup. However, these fabrics also come with many downsides for the clothing manufacturing industry. In their natural form, they are found only in neutral colors, are prone to staining, are highly flammable, and can even rot easily when wet.
To create consumer-friendly clothing, manufacturers often treat natural textiles with chemical coatings, like dyes and flame retardants. Due to cost and accessibility, favored treatments often come with an array of environmental and health concerns that can negate the benefits of choosing natural fibers.
Dyes
In their raw form, fibers such as cotton and wool are generally limited to shades of white, gray, cream, and brown. As a result, dyes and other treatments are often used to achieve the vibrant colors consumers expect from their clothing.
One of the most common textile colorants is a class of chemicals known as azo dyes, accounting for nearly 50% of global dye usage. These dyes are widely used because they produce vibrant, long-lasting colors and can be applied to both natural and synthetic fabrics. Despite these advantages, many azo dyes are classified as carcinogens, meaning they increase the risk of developing cancer. They have also been linked to many other health concerns, including skin and eye irritation and asthma.
As fibers are shed in the wash, they carry the dyes bound to them into the environment. Some dye molecules may also wash out directly into wastewater. Because azo dyes are resistant to fading and degradation in water, they are not removed by wastewater treatment facilities and make their way into rivers, oceans, and our drinking water.
Flame Retardants and Anti-Wrinkle Agents
Melamine formaldehyde resins are a common flame retardant applied to natural textiles, especially cotton. Alongside its flame-retardant capabilities, melamine formaldehyde also acts as an anti-wrinkle agent, which is especially beneficial in natural textiles that easily crease. This treatment is especially common in cotton compared to synthetic textiles due to cotton’s high flammability and tendency to wrinkle easily.
Melamine and its derivatives have been shown to adversely affect the kidneys, brain, and reproductive systems. Additionally, research has shown that washing clothing treated with melamine-formaldehyde resins one time can reduce melamine derivative levels by 76-90%. Though this limits direct exposure to melamine derivatives through clothing, these compounds then enter the environment, where their toxic effects can spread.
Oil, Water, and Stain Repellents
Since natural fibers tend to have high absorbency, they are often treated with oil, water, and stain repellents to create a protective barrier that helps keep clothing clean and dry. PFAS are synthetic chemicals commonly used as repellents in the clothing industry.
Where many treatments can repel water, PFAS contain extraordinarily strong chemical bonds, allowing them to repel both water and oil. This increases stain resistance and makes PFAS-treated clothing appealing to consumers and brands alike.
However, these indestructible bonds are also why PFAS are known as “forever chemicals.” Their structure makes it nearly impossible to break down in the environment or the human body.
Exposure to PFAS has been linked to certain cancers, thyroid dysfunction, cholesterol changes, and reduced birth weight in humans. They also accumulate in the environment, contaminating soil, water, and wildlife.
Studies have shown that aging and washing of clothing treated with oil and water repellents shed microfibers containing PFAS into the environment, allowing the amount of these “forever chemicals” in the environment to continue to grow.
Antimicrobials
Natural fibers are also frequently treated with antimicrobial agents designed to prevent odors, mold growth, and fabric degradation. Common antimicrobial additives include silver-based compounds and synthetic biocides.
While silver is a natural antimicrobial agent, studies have shown that exposure to nano-silver particles that are being used in the textile industry can lead to neurological problems, headaches, skin irritation, weakness, stomach pain, and kidney dysfunction. These silver nanoparticles flow into waterways when treated clothing is washed, where they may interfere with wildlife, as well as beneficial microbial communities in wastewater systems, soil, and aquatic environments.
Why does it matter?
While each treatment serves a practical purpose, they share a common pathway into the environment. The chemicals found in natural textiles are washed into the environment with every load of laundry. In the wash, tiny fibers shed from clothing and enter the environment, polluting our waterways, food chain, and, eventually, our bodies.
Unlike natural fibers in their raw form, chemical treatments stick around for years, creating a lasting threat. In fact, natural fibers have been shown to shed at higher rates than synthetics, meaning one load of “natural” laundry can carry significantly more fibers and chemicals into the environment than polyester.
Because both natural and synthetic materials pose significant risks to the environment and public health, it’s important to look for a solution at the source. CLEANR’s microplastic filter for washing machines captures 90%+ of fibers, synthetic and natural, before they leave your home, keeping microplastics, harmful chemicals, and other lasting pollutants out of the environment. Simple solutions like this have a huge impact on protecting what matters: ourselves and our world.
Sources
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- Akca, C. (2020). The waste problem of antimicrobial finishing. In Waste in Textile and Leather Sectors. IntechOpen. https://doi.org/10.5772/intechopen.91863
- Athey, S. N., Carney Almroth, B., Granek, E. F., Hurst, P., Tissot, A. G., & Weis, J. S. (2022). Unraveling physical and chemical effects of textile microfibers. Water, 14(23), 3797. https://doi.org/10.3390/w14233797
- Chung, K.-T. (2016). Azo dyes and human health: A review. Journal of Environmental Science and Health, Part C, 34(4), 233–261. https://doi.org/10.1080/10590501.2016.1236602
- Ling, C., Guo, L., & Wang, Z. (2023). A review on the state of flame-retardant cotton fabric: Mechanisms and applications. Industrial Crops and Products, 194, 116264. https://doi.org/10.1016/j.indcrop.2023.116264
- Negi, A. (2025). Environmental impact of textile materials: Challenges in fiber–dye chemistry and implication of microbial biodegradation. Polymers, 17(7), 871. https://doi.org/10.3390/polym17070871
- Zhu, H., & Kannan, K. (2020). Determination of melamine and its derivatives in textiles and infant clothing purchased in the United States. Science of The Total Environment, 710, 136396. https://doi.org/10.1016/j.scitotenv.2019.136396