How textile colour accelerates ocean microplastic pollution
A growing body of scientific research is beginning to quantify what the fashion industry has long suspected: synthetic clothing_ particularly polyester_ is one of the major sources of microplastic pollution in the world_s oceans. Now_ a new paper by Chen R._ Zhao X. and colleagues at the Nanjing University of Information Science and Technology_ published in Marine Pollution Bulletin_ shows that fabric colour itself may accelerate the process.
The study simulated sunlight exposure in coastal seawater_ revealing that darker PET (polyethylene terephthalate) textiles_ especially purple and green_ broke down faster and released more microfibres than lighter shades such as yellow or blue. Over a 12-day experiment mimicking one year of natural sunlight_ just 0.1 grams of PET fabric released up to 47_000 fibres.
The reason lies in physics: darker dyes absorb more ultraviolet light_ producing reactive oxygen species that weaken polymer chains_ leading to faster fragmentation. This makes black_ purple and deep green textiles disproportionately polluting_ a finding that could reshape how manufacturers assess the sustainability of coloured synthetic fabrics.
Globally_ between 20 and 53 million tonnes of plastic waste enter the oceans each year_ according to UN-linked estimates. The majority of textile microfibres come from polyester_ which accounts for roughly 60 percent of global fibre production. A single domestic laundry cycle can release around 700_000 microfibres_ many of which bypass filtration systems and enter rivers and seas.
Design compliance
For fashion and homeware brands_ this introduces a new design and compliance question. As microfibre regulation gathers pace_ with France_s 2025 filter mandate and the EU_s Ecodesign for Sustainable Products Regulation on the horizon_ the chemical profile of dyes and the physical behaviour of fabrics under sunlight will soon matter as much as their carbon footprint.
“Colour is not just an aesthetic choice_ it_s a chemical one_” the authors note. Their findings suggest that textile producers and dye manufacturers may need to prioritise low-UV-reactive dyes and re-engineer synthetic yarns to resist photo-oxidation.
Beyond compliance_ there is a reputational imperative. As sustainability becomes an investment-driven metric_ major groups from Inditex to Kering have already begun mapping their microfibre emissions. For luxury and performance brands alike_ material innovation — from solution-dyed fibres to bio-based coatings_ could become a differentiating factor in the decade ahead.
The research underscores a shift in how environmental risk is being defined in fashion. It is no longer simply about where materials come from_ but what happens to them long after the garment is worn_ washed_ or discarded.
Article source: Chen R._ Zhao X._ Wu X._ Wang X._ Wang J. & Liang W. (2024). Sunlight-Driven Photochemical Transformation of Colored PET Textiles to Microfibers in Coastal Seawater_ Nanjing University of Information Science and Technology.