Clothing made from recycled plastic, primarily recycled polyethylene terephthalate (RPET), is now a widely adopted material in the textile industry. This process transforms discarded items, such as single-use plastic bottles, into fibers used for apparel, offering a more sustainable option than virgin petroleum-based materials. Introducing a previously used material into clothing raises questions about safety, particularly concerning chemical residues, direct skin contact, and the release of tiny plastic fragments.
Understanding the Source Material and Manufacturing
The journey of plastic waste into a wearable textile begins with collection, sorting, cleaning, and shredding the plastic into small flakes. These flakes are then melted and extruded into new polyester fibers. This process carries risks stemming from the material’s history, as the input material may harbor residual contaminants. If the original plastic contained non-food substances or was improperly stored, the resulting RPET flakes can contain “Non-intentionally added substances” (NIAS) or other chemical residues. These contaminants can be introduced from the original product or formed as byproducts during the high-heat reprocessing phase. Studies show that with each recycling cycle, the concentration of certain contaminants, such as benzene, can increase in the recycled polymer.
Chemical Exposure and Residual Substances
The chemical safety of RPET textiles involves two distinct areas of concern: substances carried over from the original plastic and chemicals added during textile finishing. One carry-over substance is antimony trioxide, which is used as a polymerization catalyst in the manufacturing of nearly all PET plastics. While the majority of this heavy metal becomes chemically bound within the polymer structure, high-temperature processes, such as dyeing, can cause a small amount to leach out.
Recycled PET textiles have been found to contain other substances, including plasticizers like phthalates or bisphenol A (BPA), which are often endocrine-disrupting chemicals. These substances, along with organophosphate ester flame retardants, may be present due to the original plastic’s use or the recycling process itself.
Once the RPET fiber is formed into fabric, additional chemicals are introduced, such as specific disperse dyes used for polyester. These dyes are known skin sensitizers for some individuals. The potential for these residual and added substances to transfer to the wearer increases with factors like friction, sweat, and body heat, as they may leach out through direct and prolonged skin contact.
Microplastic Shedding and Health Implications
Like all synthetic fabrics, RPET clothing contributes to microplastic shedding, presenting both environmental and health implications. These microscopic fibers are released during the washing of garments and through friction and wear. Research suggests that recycled polyester fabrics may shed microplastic fibers at higher rates than their virgin counterparts due to changes in the polymer structure from the recycling process.
These shed microfibers become airborne as indoor dust and are released into wastewater, eventually entering waterways and the food chain. Humans are exposed through inhalation and ingestion, and the fibers can persist in organs once inside the body. Microplastics can act as carriers, adsorbing other pollutants from the environment onto their surfaces, which may then be released upon entering the body. Furthermore, the microplastics themselves can release residual chemicals from the textile into the biological system, raising questions about effects like inflammation and endocrine disruption.
Regulatory Standards and Consumer Safety Measures
Regulatory standards and voluntary certifications manage the safety of recycled plastic textiles. Certifications like the Oeko-Tex Standard 100 test and certify fabrics for the absence of harmful levels of restricted substances, including heavy metals, certain dyes, and chemical residues. For recycled materials, this standard often imposes more rigorous requirements, such as a higher testing frequency and the requirement for a proven quality management system, due to the varied and less predictable nature of the source material.
Consumers can take steps to reduce their potential exposure and mitigate the environmental shedding of microplastics:
- Choosing certified brands that adhere to strict chemical safety standards provides assurance that the fabric has been tested for hazardous residues.
- To minimize fiber release, wash synthetic garments in cold water on a gentle cycle or use specialized laundry bags that capture microfibers.
- Reduce chemical exposure by washing new garments before wearing them for the first time.
- Avoid items with heavy finishes or extremely bright dyes.