COVID-19 SPECIAL

Which is better - cleaning hands with soap or sanitiser? We put it to the bread test

After 30 days, the bread slice touched by hands that had been washed with soap stayed almost mould-free.
After 30 days, the bread slice touched by hands that had been washed with soap stayed almost mould-free.PHOTO: CLEANING EXPRESS
Slice of bread rubbed against hands cleaned with sanitiser containing 70% ethyl alcohol.
Slice of bread rubbed against hands cleaned with sanitiser containing 70% ethyl alcohol.PHOTO: CLEANING EXPRESS
Slice of bread rubbed against hands cleaned with alcohol-free sanitiser.
Slice of bread rubbed against hands cleaned with alcohol-free sanitiser.PHOTO: CLEANING EXPRESS
Slice of bread rubbed against laptop.
Slice of bread rubbed against laptop.PHOTO: CLEANING EXPRESS
Slice of bread rubbed against mobile phone.
Slice of bread rubbed against mobile phone.PHOTO: CLEANING EXPRESS

With the circuit breaker period coming to an end on June 1, the number of Covid-19 cases is expected to rise as people gradually resume their activities.

Observing good hygiene will remain critical in order to keep community transmission low and stable.

This much was proven by an experiment conducted by professional cleaning company Cleaning Express for The Straits Times.

Five slices of bread were rubbed against various surfaces - cleaned hands, a mobile phone and a laptop.

Three of the slices were rubbed with hands that had been washed with three different products: hand soap, 70 per cent alcohol hand sanitiser and non-alcohol hand sanitiser containing a coronavirus-killing chemical.

After 30 days, the differences were clear. The two slices that stayed almost mould-free were those touched by hands that had been washed with soap and sanitised with 70 per cent alcohol.

The slice which had been in contact with the mobile phone had turned almost black with large clusters of bread mould, the most common form of fungal contamination in bread.

Professor William Chen, the Michael Fam chair professor and director of Nanyang Technological University's Food Science and Technology Programme, said that while fungi is most visible on the contaminated bread surface, other invisible microbes, such as bacteria and viruses from the surface of the phone, could also be present.

The fungi produces toxins known as mycotoxins, which can cause diarrhoea and more severe intestinal problems when ingested.

Typically, consuming mouldy bread may result in allergic reactions as well as food poisoning.

The slice of bread which had been rubbed against the laptop had less mould compared with the one rubbed against the mobile phone, a result attributed to usage frequency.

 
 
 
 

To ensure that personal devices are well-sanitised, Prof Chen said they should be cleaned with an alcohol-based disinfectant that is user-safe, convenient and evaporates quickly.

Mobile phones, which are more frequently used, should be disinfected at least three times a day, preferably before each meal.

However, consumers also need to consider their own skin conditions, he added, as using an alcohol-based sanitiser frequently could cause skin dryness.

Prof Chen also advised developing good personal hygiene habits, such as regularly washing hands, especially before and after meals.

 
A version of this article appeared in the print edition of The Straits Times on May 23, 2020, with the headline 'Bread experiment shows good personal hygiene matters'. Print Edition | Subscribe