sciencetech-blog

comments

Scroll down for video

Clothes that are marketed as anti-odour could be harbouring a smelly secret, according to a new report.

Socks and other items of clothing shown to be anti-odour in laboratories may not be once when they are put into real use next to human skin, the University of Alberta, Canada, study found.

Antomicrobial textiles, those which kill or limit growth of microorganisms, may have almost no effect when used in the real world - meaning you might smell a whole lot more than you realise.

Stinky secret: Socks and other items of clothing shown to be anti-odour in laboratories may not be once when they are put into real use next to human skin

In two separate experiments, Human Ecology researcher Rachel McQueen and her team found that some antimicrobial textiles were far more effective at performing their advertised tasks in the lab than in testing on humans. 

Student gauges bacteria in blue jeans after 15 months of unwashed...

'We aren't necessarily seeing the same results in the lab about antimicrobial activity translating into antimicrobial activity when we're wearing them next to our bodies in real life,' she said. 

Dr McQueen added that anything from sweat to the proteins in the human body can disrupt the antimicrobial properties of a fabric. 'In reality, when it goes to the point that it gets put on a textile, it may not have the same level of effectiveness as the ones they studied,' she said.

Dr Rachel McQueen of the University of Alberta

In one experiment, the fabrics were designed to help lower the risk of infection, and in the second, the fabric was treated with a silver compound, which can be marketed as preventing odour in clothing. 

The first experiment analysed the effectiveness of three different textiles coated in antimicrobials triclosan, a zinc pyrithione derivative and a silver chloride-titanium dioxide compound. After putting the fabric on people's arms under plastic film for 24 hours, the compound hardly eliminated any bacteria.

The second experiment had similar results, and tested whether polyester textiles treated with bioactive concentrations of an antimicrobial silver chloride compound reduced armpit odour and bacterial populations. 

Although lab testing showed antimicrobial activity, the treated fabrics did not lower odour or bacterial intensity when tested on people. 

Overall, the team found that the in vivo (tested on humans) results were not comparable with in vitro (tested in the lab) results in how they prevented microorganisms from surviving in the textile.

Dr McQueen said the findings highlight the importance of in vivo testing, which is less common than in vitro testing, in textile product development. 

But, because the textiles appear to be effective at reducing bacteria in the lab, she said they can still be advertised as being anti-odorous, even when they are not when worn.

So, for now, Dr McQueen suggests thinking twice before trusting textile's advertised claims.

'It's just a real spectrum to how effective they may truly be. So I'd probably say, from a consumer's point of view, if you're actually buying something that says it's antimicrobial, it may not be,' she said. 

'I think that's important to consider in relation to a lot of claims made about textiles, that is, to be sceptical about the claims marketers make.'