Five Second Rule

Five second rule – true or not?

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When I drop food on the floor, an automatic five-second timer starts ticking in my head. In a swift motion, I picked the food up and pop it in my mouth before my Mom can stop me. “Five second rule!”, I shout before my mum can say anything. A look of annoyance furrows her eyebrows because she hates it when I do this.

But can bacteria gets into food before those famous five seconds are over?

Though food that has fallen is most likely safe to eat, it does not mean that bacteria has not gotten into our food. Bacteria from any surface will DEFINITELY transfer to your food once dropped. However, it is unlikely that the bacteria is harmful enough to hurt your body.

That being said, the nature of the floor surface, the type of food dropped on the floor and the length of time it stays on the floor determine the amount of bacteria that gets into your food.

Nature of the floor surface.

Imagine dropping a slice of pizza on a carpeted bedroom floor and a kitchen floor respectively. Which pizza would you pick up and continue eating?

I’m pretty sure that most people would choose the pizza that has fallen on the carpeted bedroom floor. Indeed, a carpet has a very low rate of bacterial transfer compared with tile and stainless steel. Moreover, the contact area of the food and carpet is smaller due to its thin fibres.

And of course, food dropped outdoors or covered with obvious dirt should not be eaten at all.

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Type of food dropped on the floor.

Now imagine dropping a plate of pasta and a bag of chips on the floor. Would you continue eating them?

A logical person would clean up the pasta mess, throw the pasta into the bin and perhaps recook another plate of pasta or head out to satiate his or her hunger. Depending on how hygienic the person is, they may choose to pick up the chips, gently blow off any dirt on them and continue eating them as long as they keep to the five second rule.

It almost seemed like a natural instinct to discard moist food that have dropped on the floor.

In an experiment done by researchers from Aston University, food such as biscuits, cooked pasta, sticky sweets and toast were dropped to the ground and the amount of germs that transferred to the food within three minutes and thirty seconds were recorded. The experiment concluded that moist food such as cooked pasta picked up almost 20 times more germs than dry food such as biscuits and toast – in the same length of time the food stayed on the floor!

The length of time the food stays on the ground.

The longer the food stays on the floor – no matter what surface and type of food – the higher the transfer of the germs. When a piece of toast is left on the floor for a minute, the rate of transmission will be amplified by 10 times the initial rate.

This could be the obvious reason why the five second rule was originated – where this length of time is still more or less safe for the food to be eaten.

Side note on the cleanliness of blowing birthday candles.

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Did you know that after the huffing and puffing – and sometimes spitting – the level of bacteria on the birthday cake increases by 1,400%! However, this is not a major health concern as it has been scientifically backed that even if we blow out the candles 100,000 times, the chances of getting sick is still very minimal.

With that being said, bacteria is always present everywhere around us therefore it’s best that we keep ourselves hygienic and comply to the zero second rule instead!

Have a great day everyone. 🙂


– All gifs adapted from –

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