Sportswear and silver leaching to the urban water cycle

Last year’s Biocides Europe conference (which took place in Vienna on 3-4 December) brought together a diverse range of stakeholders to discuss key aspects of the Biocidal Products Regulation (BPR). 

One of the speakers at the event was Anders Finsson, Senior Environmental Advisor at the Swedish Water & Wastewater Association (Svenskt Vatten). He presented the findings of a new report on the leaching of antibacterial silver from sportswear. In this article, he provides an overview of the report’s key findings, including the fact that up to 90% of silver in sportswear can leach out after just ten washes. 

Anders Finsson
Senior Environmental Advisor
Swedish Water & Wastewater
Association (Svenskt Vatten)

The report which I will present at Biocides Europe in December is about the leaching of antibacterial silver from sportswear. 

The intention with the report is to highlight the problems created by silver for our environment and water cycle. The Swedish Water & Wastewater Association wishes to highlight above all the leaching of silver which takes place when washing this clothing and which will, over time, affect life in our lakes and seas, as well as the possibilities for a sustainable circular economy.

Silver is used in items such as sportswear because of its antibacterial properties. What many consumers do not know is that silver is classified as a biocide; that is to say, a toxin. In the long run, the silver found in the water cycle can pose a significant threat to the wealth of life in the sediments of our lakes and seas. Sediment-dwelling creatures and organisms play a crucial role in the biological networks created by nature.

A large problem with silver in sportswear is that the silver leaches out on washing the clothing. That is to say, the silver ends up in wastewater and eventually in the urban water cycle. Companies that market odour-reducing treatment sometimes claim that no leaching takes place during washing. However, the Swedish Water & Wastewater Association has carried out washes in a laboratory setting and can demonstrate that leaching takes place in all silver treatments on sportswear. Between 31% and 90%, with a median value of 72% of the silver had leached out after 10 washes. The worst case was a pair of tights which had been treated with Polygiene and bought at, and contained only one tenth of the silver content after ten washes. The remainder – 90% – had leached into the wastewater.

Another effect of the use of silver in society is the rise in antimicrobial resistance (AMR). A study by Susanne Sütterlin, a researcher and specialist doctor in clinical microbiology at Uppsala University, showed that silver seemed able to reduce the level of sensitivity/resistance to antibiotics.

We have also looked at the way this so-called anti-odour clothing is labelled. According to current EU legislation – the Biocidal Products Regulation 528/2012 – labelling should show whether an article contains a biocide; that is to say, a substance classified as a toxin. The word “biocide” or “biocidal product” ought to be stated. Moreover, the labelling should also state which biocide; that is to say, which toxic substance, has been used to treat the garment. Clothing brands are not very successful in following the regulations regarding labelling.

Summary of the report:

•  Clothing treated with silver may pose a threat to sediment-dwelling creatures and organisms in our lakes and seas. So called sediment-dwelling organisms are more sensitive than we have previously thought.

•  We are aware today that the antibacterial silver leaching from treated textiles is the largest known source of silver in our treatment plants, at the same time that the amount of silver entering the treatment plants must be reduced by more than half if the water cycle is to be sustainable in the long run.

•  Antibacterial silver in clothing leaches out in the wash and always increases the amount of silver ending up in the wastewater treatment plants – this clothing is therefore taking the trend in the entirely wrong direction.

•  After ten washes the amount of silver leached from the silver-treated clothing is 31-90%. The median lies at 72%, according to the laboratory analysis commissioned by Svenskt Vatten. This means that two thirds of the silver has leached out after ten washes.

•  A total of 15 garments were tested in laboratory conditions. All of these were labelled in some way as anti-odour (for example, “prevents bad odours”, “for lasting freshness”, “anti-odour”). Nine out of 15 contained silver, according to the laboratory analysis.

•  The clothing brands are sloppy with their labelling. According to EU regulations, each so-called anti-odour garment should have a label clearly stating which biocide has been used to treat it. Several clothing brands are poor in this respect.

•  Retailers fail to inform consumers about which toxic substances are present in the clothing. They should by law provide answers to any questions they receive from consumers on this issue within 45 days. When we asked them, several were unable to state which active biocides were used to treat their anti-odour sportswear.

•  Bluesign, which is an environmental standard, accepts the presence of silver in clothing despite the fact that according to our laboratory analysis it leaches silver into the water cycle.

The Swedish Water & Wastewater Association’s requirements:

•  The spread of antibacterial silver in the environment must stop.

•  The industry must begin to phase out all clothing and textile articles that have been treated with silver. Starting today.

•  Manufacturers must be much better at labelling their clothing correctly. Labelling must clearly state that the garment has been treated with a biocide.

•  There is a need to introduce requirements that ensure clearer labelling. For example, one absolute requirement should be that biocide-treated articles sold on the Internet are clearly labelled on both the website and the garment that arrives in the post.

•  Consumers ought to avoid buying ‘anti-odour’ clothing if they are unsure whether or not these contain silver. Always ask in the store.

•  Svenskt Vatten would like to know why clothing treated with silver meets with Bluesign’s approval. What consideration does Bluesign give to the fact that a significant part of the antibacterial biocide is washed out and ends up in our waters and the water cycle.

You can find the full report at this link: