Doctor, your research group together with Aquafil created a standard method to measure microplastics release. Could you explain what the main goals of this collaboration are?

“Well, as a matter of fact, my institute, CNR STIIMA in Biella, in cooperation with Aquafil, developed a standard method, ISO 4484-2, published in the 2023, which belongs to a set of three ISO regulations aiming at determining microplastic shedding from textile sources.
The main purpose was to obtain standard experimental reliable data that can be compared. In particular, our method allows technician to get detailed information such as, for example, shape, size, area, volume, and chemical composition about microplastic by using optical microscopy coupled with FTIR spectroscopy. This method is extremely versatile, used to determine and identify microplastic fibers in solid or aqueous samples, such as, for example, waste water, laundry water, or airborne material in workplaces.”

Very interesting. And could you tell us what are your latest results? For example, which fabrics are the worst polluters in our washing machines?

“Okay. Our latest results have pointed out that it is the mechanical or chemical finishing, as well as the polymer quality, that can make a difference. In one of our experiments in my lab, determining the release of microplastic during a simulated washing cycle, a printed continuous filament PET T-shirt released more microplastics than a plushy staple fibers sweatshirt that had undergone a shaving process.
So, we are able to spot the difference thanks to ISO regulation 4484-2 and to realize that the residue released during washing consist mainly of silicone finishing and PET oligomers due to excessive use or poor quality of the polymer. So, generally speaking, synthetic garments made up of staple fiber, yarn with little twist, a knitted fabric with a marked propensity to pilling or high propensity to breaking—for example, perforation force—are the ones that release the most microplastics and, therefore, the worst polluters.”

That’s really insightful. Thank you so much. Talking about specific fibers, we often group nylon and polyester together. But based on your research, what are the main differences in fiber shedding between the two?

“A good question, but this is a difficult question to answer. First of all, because nylon data are very, very scarce and in most cases obtained without using any new standard method. And secondly, because the two polymers fibers are used in completely different fields and often blended with other fibers, for example PET with cotton.”

Okay, fair enough. Let me phrase it differently. Based on what you shared before, it’s clear that fabric structure is crucial. But what matters more: the material (nylon, polyester) or the texture (like if we have a brushed fleece or staple fiber compared to a compact swimsuit with continuous filament)?

“All the listed features can influence microplastic release, and this is the reason why it is necessary to analyze each textile parameters individually to be able to determine with certainty the factor that is the strongest, also because in some cases the parameters are linked together.”

Thanks, super clear. Now, let’s look forward. Now that, thanks to your work, we can measure fabric’s shedding, what’s the next step? Could this method help us understand which materials, structures, and processes influence microplastic shedding and maybe eventually guide eco-design choices in the textile industry? Do you think we’ll soon be able to act directly at the source, offering guidance on yarns, fabric treatments, or even developing finishes that fix fibers more firmly onto the fabric?

“Yes, no doubt. ISO regulations allow quantification in standard way of the products and processes that need to be developed. The first step involves collecting all the data obtained by using standard protocol, analyze them, and using them to provide guidelines in order to make sustainable items of clothing with a low microplastic release resulting from the clear definition of the eco-design criteria of, for example, better operative conditions and innovative anti-release treatment without any significant textile changes.
But this goal can only be reached through the cooperation of research laboratories and the whole textile chain—for example, spinning, orthogonal and knitted weaving, dyeing, finishing. And I would like to add that all these proposals belong to a wider project involving the Polytechnic of Turin and textile companies.”