It’s one of the most basic rules of hygiene, but new figures have now revealed the staggering number of Aussies who aren’t washing their hands when they go to the toilet – with one age group singled out as particularly bad.

While more than 20 percent of people admitted to neglecting the soap and water after visiting the loo, two in five don’t bother to wash their hands before sitting down to eat, according to figures from The Food Safety Information Council. And experts have now warned the poor hygiene habits could be contributing to the spread of disease across the country.

“Good handwashing, using running water, soap and drying hands thoroughly is a basic public health message that people seem to be forgetting,” Lydia Buchtmann, the council’s communication director, said. “A fifth of Australians say they don’t always wash their hands after going to the toilet and more than a third admit they don’t always wash before touching food.

“This behaviour could be contributing to the estimated 4.1million cases of food poisoning each year not to mention spreading viral infections such as cold, influenza and norovirus.”

While men proved to be worse at neglecting their hands than women, the worst age group came out as younger people under the age of 34 – sparking more fears as many of them will be working in the food industry.

“Men were less likely than women to always wash hands after going to the toilet (76 per cent of men versus 82 per cent of women) and before touching food (59 per cent men versus 66 per cent women),” Buchtmann added. “Young people were less likely than older age groups to always wash their hands after going to the toilet (69 per cent under 34 years versus 86 per cent over 50 years) and before touching food (59 per cent under 34 versus 63 per cent over 50). Poor handwashing knowledge among young people is also a concern as they often become professional food handlers.”

In an effort to ensure diseases don’t spread, the council has offered advice on the most effective way to wash your hands. They say you should start by wetting your hands and rubbing them together with soap to build up a good lather, working them together for at least 20 seconds and ensuring you cover in between fingers and under nails.

Next they advise rinsing them well before drying them thoroughly with a towel for around another 20 seconds, as touching surfaces with wet hands only encourages germs to spread.

While you may think there’s no harm in washing your hands in a dryer of a public bathroom, a Facebook user previously sparked a debate when she revealed how germ-ridden these dryers can really be. Nichole Ward, from California, wanted to show her friends and followers just how unhygienic the dryer was.

“Ok guys.. ready to have your mind blown?!” she asked. “This here, is what grew is a Petri dish after just a few days. I stuck the open plate in an enclosed hand dryer of a public bathroom for a total of 3 minutes. Yes 3 only.”

“DO NOT EVER dry your hands in those things again,” she said. “This is the several strains of possible pathogenic fungi and bacteria that you’re swirling around your hands, and you think you’re walking out with clean hands. You’re welcome.”

In most cases, flu is most infectious in the first five days. Where possible, always try to sneeze or cough into a tissue and bin it as quickly as possible. Leaving it in your handbag or pocket could increase the chance of germs spreading further.