Research has found that the use of silver nanoparticles to prevent unpleasant odour caused by bacteria in sport shirts or socks can be more environmentally sustainable than other treatments, even though a question mark remains on their potential risks.

As part of an EU funded project called Prosuite, researchers analysed the environmental impact of nanosilver T-shirts during their entire life cycle, from raw material extraction to end-of-life disposal.

The scientists found that the T-shirt’s environmental impact during use would be reduced if they are washed less often than conventional ones, due to their antimicrobial properties. This would even compensate for a slightly higher climate footprint during production.

However concerns remain over the effect nanosilver may have when it is released into wastewater during washing. Studies shown that nanosilver presents a minute risk to the environment as it is transformed into a nearly insoluble substance called silver sulphide in wastewater treatments. 

"Nanosilver can be applied in lower quantities than other antimicrobials and hence has advantages for resource use and environmental loads," said Tobias Walser, a researcher at the Institute for environmental engineering at the Swiss Federal Institute of Technology.

However, 'the environmental and human risk of nanosilver has yet to be fully understood," he added. 

That said,, "In comparison to all toxic releases during the life cycle of a T-shirt, the toxic releases from nanosilver from washing appear to be of minor relevance."