Recycled polyester (rPET) is a synthetic fiber created by processing post-consumer waste, most commonly polyethylene terephthalate (PET) plastic bottles. The recycling process involves cleaning, shredding, melting, and spinning the plastic back into a fiber suitable for textiles. The resulting material is chemically identical to virgin polyester, but its production requires less energy and reduces reliance on fossil fuels. Since rPET is sourced from waste, consumers often question whether the recycling process introduces health risks.
Chemical Residuals from Source Materials
The most direct concern unique to recycled polyester is the potential carry-over of substances originally present in the plastic source materials. Before recycling, PET bottles may have been exposed to contaminants like food residues, cleaning agents, or various chemicals. Although rigorous cleaning steps are part of the recycling process, trace amounts of these non-PET substances can theoretically remain in the final fiber. Antimony Trioxide, a heavy metal routinely used as a catalyst in the production of all PET, is known to remain in the finished polymer.
The method of recycling plays a significant role in the purity of the final product. Mechanical recycling, the most common method, involves melting the plastic, which may not completely eliminate all contaminants. Chemical recycling, in contrast, breaks the polymer down to its basic monomers before repolymerizing it, resulting in a final product with purity comparable to virgin polyester.
Toxicity in Textile Dyes and Finishes
The safety of any polyester textile, recycled or virgin, is heavily influenced by chemical treatments applied during manufacturing. These treatments include coloring agents, waterproofing, and performance finishes designed to enhance functionality. Many of these substances have the potential to leach from the fabric and into the wearer’s skin. For example, Azo dyes can break down to release aromatic amines, which are classified as possible carcinogens.
Heavy metals like lead, cadmium, and chromium are sometimes used as colorants, and their presence can be toxic if absorbed. These substances can cause skin irritation or allergic contact dermatitis, especially in garments worn close to the skin. Other finishing chemicals, such as formaldehyde, are used for wrinkle resistance and can cause skin or respiratory issues. Per- and polyfluoroalkyl substances (PFAS) are often used for water-repellency but have been associated with immune system suppression and other adverse health effects.
Microplastic Shedding and Health Risks
A safety concern inherent to all synthetic fabrics, including rPET, is the shedding of microplastic fibers during use and washing. These microscopic plastic filaments enter the environment and pose a risk to human health through inhalation and ingestion. Microplastics have been detected in human tissue and can potentially cause inflammation or physical irritation. A significant health concern is their role as a vector for chemical exposure, as they can attract and absorb environmental toxins like flame retardants.
When inhaled or ingested, these microplastic carriers can release absorbed toxins into the body, potentially leading to endocrine disruption. Chemicals present in microplastics can also leach into human sweat and be absorbed through the skin, entering the bloodstream. Consumers can take steps to mitigate fiber shedding from rPET garments:
- Washing synthetic textiles in cold water.
- Using shorter wash cycles.
- Minimizing the frequency of washing.
- Using specialized washing bags or installing a washing machine filter.
Assessing Safety Through Industry Standards
Third-party certification bodies provide a reliable system for consumers seeking assurance about the safety of recycled polyester. These standards address both the material’s origin and the chemical safety of the final product. The Global Recycled Standard (GRS) verifies the content of the recycled material and tracks it through the supply chain, ensuring rPET is genuinely sourced from post-consumer waste. The GRS also sets requirements for environmental and social practices, including strict chemical restrictions during manufacturing.
The OEKO-TEX Standard 100 focuses on the human health safety of the finished product. This standard tests every component of a textile article, including threads and accessories, for the presence of over 100 harmful substances. When a recycled polyester product carries both GRS and OEKO-TEX certification, it is generally considered safe for consumer use.