High silver levels in some period pants could pose health risk, study says

Some period pants sold by high street retailers contain high levels of silver that could have health and environmental implications for consumers, an investigation has found.

Silver is used as an antimicrobial agent and is typically added to period pants to combat user concerns about smell and hygiene.

However, scientists have increasingly warned about the potential health effects. The US Food and Drug Administration found that nanosilver can kill lactobacillus, the healthy bacteria in the vagina that help fight off infection. This can put period pant users more at risk of harmful bacteria, potentially leading to an increased risk of bacterial infections and pregnancy complications.

Natalie Hitchins, the head of home products and services at Which?, said: “Consumers should be cautious buying period pants which contain silver as experts have concerns about the health implications.

“Which? believes brands should also clearly state which products contain silver so shoppers can make informed decisions about what they are buying and the possible risks.”

The consumer rights group worked with an Italian consumer organisation, Altroconsumo, to independently test popular brands and check if they contained any chemicals of concern. They were worried to find that some products contained significant levels of silver, and this was not always made clear on the packaging.

Intima by Bodyform and pants by Marks & Spencer in particular contained notably more silver than other brands, at 126.7mg/kg and 57.8mg/kg respectively. Other brands contained 8.3mg/kg, 7.4mg/kg, and 0.9mg/kg.

Essity, the owner of Bodyform and Modibodi, said silver copper zeolite was used to “prevent odour when wearing the pants for up to 12 hours”. It added that all of its “washable underwear is certified according to Oeko-Tex Standard 100, which means that every single component has been tested for harmful substances” and “that the underwear has been designated as harmless for human health”.

Marks & Spencer declined to comment.

Which? said it believed the use of silver was unnecessary and that previous testing by Altroconsumo had shown that textile items treated in this way did not have the promised antimicrobial properties.

The European Chemicals Agency says silver treatments, such as nanosilver and silver zeolite, are toxic to aquatic life with long-lasting effects.

The tests Which? carried out can detect any silver above 0.1mg/kg, and it found none in Primark, Repeat, Wuka, Lovable and Sloggi pants. Sloggi’s website says it does use a silver-based antimicrobial, and Primark says it uses Micro-Fresh, which contains silver chloride.

A Primark spokesperson said: “The nature of period pants means there is a potential for odour to develop during wear (in the same way that bacteria can cause socks and shoes to develop odours during wear) and our antimicrobial finish minimises such odours.”

Sloggi did not reply to Which? at the time of publication.

There are no legal limits in the UK about how much silver can be added to period pants. Manufacturers do not have to declare the presence of silver on their packaging or website.