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The Truth Behind the Myths: Hot Water Hand Washing and The Five Second Rule (Infographic)

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The Truth Behind the Myths: Hot Water Hand Washing and The Five Second Rule (Infographic)

Many misconceptions have been handed down from generation to generation about germs. Prevention magazine cracked the case about the germiest public places (hint: it’s restaurant menus, condiment dispensers and grocery carts). However, mystery still surrounds a few myths about hand washing and the five second rule when food is dropped on the floor. Find out the truth about these two myths and start leading a healthier life for you and your family!

Hot water hand washing and five second rule infographic.

Myth One: Using hot water to wash your hands kills more germs.

This old wives’ tale is not true. National Geographic reported that people in the US are washing their hands with water that is hotter than necessary. Citing a team of researchers at Vanderbilt University, the article states that the temperature required to kill bacteria is 212°, the equivalent of boiling water. Human skin cannot tolerate this kind of heat. The researchers discovered that the average water temperature people used while washing their hands was between 104° and 131°. While this amount of heat has the possibility of killing germs, the amount of time required in constant contact with the hot water would damage the first layer of the skin. The damage, in turn, would make us more susceptible to bacteria as we would have decreased our defense system.

The group says that water as cold as 40° still reduces the amount of bacteria on the skin when hands are washed properly. Proper hand washing consists of scrubbing, rinsing and drying hands. The World Health Organization offers this handy chart on how to properly wash your hands. The process should take between 40 and 60 seconds and includes wetting hands, applying ample soap, rubbing hands thoroughly, rinsing thoroughly, completely drying hands and turning off the faucet with a paper towel. The chart never mentions a particular water temperature.

Our recommendation: 

Wash your hands frequently and don’t worry about the water temperature. The best way to stay healthy and happy is to keep germs at bay!

Myth Two: As long as you pick up food that was dropped on the floor in 5 seconds or less, there won’t be any germs on it.

This myth has been debated for a long time, and the science goes either way. What is true is that any food dropped on the floor, for any amount of time, will have germs on it. The amount of germs and the type depend on the consistency of the food and the odds of dangerous bacteria being on that particular part of the floor. National Public Radio reported on a study done by biology students at Aston University in Birmingham, UK. The students completed an experiment on how much bacteria was found on food dropped on tiles, linoleum and carpet for various amounts of time. They found that sticky foods picked up bacteria faster than dry foods and that food dropped on the carpet was contaminated with the least amount of germs. The team also surveyed 500 people and discovered that 87% of them ate food off of the floor. Of that 87%, three-quarters used the five second rule.

Not all scientists agree with the student’s findings. Microbiologist Eric Schulze at expressed a warning about the five second rule. He stated that it could take less than five seconds for hundreds of bacteria to attach themselves to food on the floor. After one minute, that number increases to ten times more bacteria. His advice is simple: People track things like fecal matter on the bottoms of their shoes. While not all of the bacteria on the floor is harmful to people, it’s an issue of risk each time you decide to eat it. Eating food off of the floor means that you are taking the chance that your food did not fall in the area of harmful bacteria. But remember, one in six Americans gets a foodborne illness each year. According to the CDC, the most common of which is Norovirus, which is caused by fecal matter.

Our recommendation: 

Don’t eat food off of the floor. Just throw it away. The chance of picking up an illness from the floor is not worth it!

Stay healthy this winter and teach the whole family to toss out that food that falls on the floor and to follow proper hand washing!