Synthetic Textiles: Plastic pollution is a pervasive issue, but its reach extends beyond usual suspects like bags and bottles. A recent study by UC San Diego’s Scripps Institution of Oceanography has shed light on the alarming presence of plastics in textiles, such as clothing and rugs. Published in the journal PLOS One, the study examined the biodegradability of various fabrics in an oceanic environment, uncovering concerning findings about the textile industry’s environmental impact.

Led by Sarah-Jeanne Royer, the study conducted experiments to assess the degradation capabilities of different fabrics. The results revealed that natural and wood-based cellulose fabrics broke down within a month when exposed to the ocean environment. However, synthetic textiles, including materials marketed as compostable plastics like polylactic acid (PLA) and the synthetic components of textile blends, showed no signs of degradation even after more than a year submerged in the ocean.

Biodegradable only in industrial settings?

Royer emphasizes the need for standardized tests to determine whether materials promoted as compostable or biodegradable break down in natural environments. It is crucial to understand that what may biodegrade in controlled industrial settings does not necessarily do so in the natural environment, leading to potential marine and environmental pollution.

The impact of plastic pollution in the textile industry is starkly illustrated by disturbing images of overflowing landfills filled with discarded clothing in countries like Chile and Kenya. Approximately 68 million tons of textiles, or 62 per cent, are now made from plastic fibres and blends, which can persist in the environment for many decades, even centuries. Several of our articles on the topic of sustainability covered the problem of the clothing industry and some highly innovative solutions. Synthetic textiles also contribute to plastic pollution by shedding microfibers during regular use and washing. Unfortunately, most washing machines lack the capacity to filter out these microfibers, resulting in their release into wastewater and ultimately ending up in the ocean.

Bio-based plastics, derived from renewable resources like cornstarch or sugar cane, have been promoted as potential solutions to the plastic problem. PLA, a popular polymer in the bio-based plastics market, is often labelled as biodegradable and compostable. Given its widespread use as a substitute for oil-based materials, the researchers selected PLA for their study.

Testing some bio-based materials

The experiment tested ten different types of fabrics, including wood-based cellulose, natural cellulose, bio-based plastic, oil-based plastic, and fabric blends. These fabrics are commonly used in the textile industry. The samples were placed in flow-through containers deployed at the sea surface and seafloor and examined every seven days. High-resolution imaging and further analysis were conducted in the laboratory. The natural cellulose-based textiles consistently disintegrated within 30 to 35 days, while the oil-based and bio-based materials showed no signs of degradation even after 428 days, which is quite alarming.

Using electron microscopy, the researchers observed changes in the size and structure of the fibres. The natural fibres became thinner over time, indicating biodegradation, whereas the plastic fibres remained unchanged. Raman spectroscopy, another analytical technique, revealed significant changes in the cellulose-based materials’ chemical composition and molecular structure, whereas the bio- and oil-based plastics showed no such changes.

Are some fabrics truly more sustainable?

Fibre blends, which combine natural and plastic strands, have been marketed as more sustainable alternatives to textiles made entirely from synthetic plastics. However, the study found that only the natural components of the fibre degraded, while the plastic portions remained intact.

The study authors stress that bio-based plastics like PLA often assumed to be biodegradable in the environment due to the “bio” prefix, are not as environmentally friendly as previously believed. These findings emphasize the importance of accurate and informative language surrounding plastics.

Royer and her team hope that consumers will recognize the power of their choices in mitigating plastic pollution. Consumers can reduce their environmental footprint by opting for high-quality cellulose-based materials like cotton, merino, or wool. They also encourage adopting circular and sustainable practices – you can read more about these in our articles –- such as clothing swaps and Buy Nothing groups to repurpose items and minimize waste.

The study received funding from the Biomimicry for Emerging Science and Technology (BEST) Initiative, Lenzing, The Walter Munk Foundation for the Oceans, and Preserve Calavera. The Young Thousand Talents Plan of China supported the Raman analysis.

The collaborative effort underscores the urgent global need to address plastic pollution in the textile industry and highlights the importance of responsible consumer choices in promoting a more sustainable future.