Academics from Heriot-Watt University have formulated a five-point visual scale for quick and cost-effective assessment of the microplastic fibre shedding potential of fabrics.

The European Environment Agency (EEA) estimates that over 14 million tonnes of microplastics have accumulated on the world’s ocean floor, an amount which increases each year. With approximately 16-35% of microplastics released into the oceans anually3 coming from synthetic textiles, it is a problem that needs to be addressed.

Heriot-Watt University, a global research-led university based in the UK, with five campuses in Edinburgh, the Scottish Borders, Orkney, Dubai and Malaysia, is looking to do just that.

For four years, a small team headed by Dr Lisa Macintyre, associate professor of textiles at the University’s School of Textiles and Design in the Galashiels campus, has conducted a new project aimed at making fashion brands and consumers more conscious of the environmental impact of their garments with a world first visual ‘fibre fragmentation scale.’

The five-point scale assesses the volume of fibre fragments shed from different clothing materials from visual grades, with grade one having the highest volume of shed fibres to grade five with the least.

Unlike existing methods, this new process is fast and cost-effective, making it more suitable and scaleable for large volumes of material, so garment manufacturers can readily assesses and identify lower shedding materials for production of their products.

If adopted by industry, the fibre fragmentation scale could be displayed on clothing labels, similar to the way many UK food manufacturers display calorie information on packaging.

The findings have featured in a new paper, entitled, Low-cost, high-throughput quantification of microplastics released from textile wash tests: Introducing the fibre fragmentation scale, and published today (19 Nov) in the peer-reviewed journal, Cambridge Prisms: Plastics.

Dr Macintyre commented, “The microplastics problem is massive. Fashion and textiles is one of the biggest sources of secondary microplastics in the environment with fragments of plastic fibres, like polyester and nylon, being shed from clothing.

“There are fibre fragments absolutely everywhere, from icebergs to the deepest ocean to human lungs and our food – they’re in everything. 

“Visual scales are already used in the fashion industry to measure how much bobbling a material may suffer on its surface for example or, perhaps the most well-known is the grey scale, which measures colour fading or staining, but there was no such tool for fibre shedding. 

“This project aims to change that and allow manufacturers to not only make better choices in production but also to communicate to their customers in a very simple and straightforward way, the typical amount of fibres shed from a garment.”

Fibre fragments can vary in size between a fraction of a millimetre to several centimetres in length, and can cause significant negative impacts, despite their small size, to ecosystems, wildlife, and human health.

As part of the process of testing the fibre shedding scale, textile samples were placed in a ‘rotawash’, an eight-canister machine that churns the samples with water, simulating the process of a washing machine. The wastewater was then filtered to capture the fibres and assessors visually evaluated the volume in each sample against the fibre fragmentation scale.

Volunteer assessors heralded from the fashion industry, university student bodies, and general public volunteers, totalling 46 testers over two years, grading approximately fabric 100 samples.

Sophia Murden, PhD student of fibre fragmentation studies at Heriot-Watt University, who has been working alongside Dr Macintyre on the project, explained that their five-point scale is “surprisingly more accurate at assessing very low levels of fragmentation than the equivalent method of weighing fibres. “The ultimate aim is for manufacturers to choose materials that are going to have the least impact on our environment but also allow consumers to make an informed decision when they buy their clothing.”

Dr Macintyre added, “The next stage for us is to try and get some kind of industry agreement. Currently, we don’t have an ‘acceptable fragmentation’ rate for clothing but that’s not unusual. The environment is an important issue, and we’d want to get key industry leaders and policymakers to sit down and start agreeing standards, perhaps even legislating against high shedding materials.”

The project has been funded through the University’s James Watt Scholarship which is aimed at advancing research for the benefit of society.