Is the ‘five-second rule’ actually true?

Is the ‘five-second rule’ actually true?

Posted on Oct 19, 2016

Is the ‘five-second rule’ actually true?



We’ve all heard of – and have probably used – the five-second rule, right?

If, for some reason, you haven’t, it’s basically a theory that if you drop some food on the floor it’ll still be fine to eat, as long as you pick it up again within 5 seconds.

At flick we’ve had a strong suspicion for a long time that the five-second rule isn’t something that should be followed, but now a new study has taken place in America to find out once-and-for-all whether or not it is actually true.

Donald Schaffner of Rutgers University in New Jersey is a food microbiologist, and has spent the last 2 years leading a study – ‘Is the five-second rule real?’ – not only looking to answer the question but also whether a longer time spent on the floor meant that the food became more contaminated.


So, is it real?

In short, no (as we suspected!).

Four different foods were tested (watermelon, bread, bread with butter, and gummy bears), each dropped on to four different surfaces (stainless steel, tile, wood and carpet), and left on each surface for four different lengths of time (1 second, 5, 30, and 300 seconds).

The results show that watermelon consistently picked up the most bacteria, and the gummy bears the least. The carpet surface gave off the least amount of bacteria, and the stainless steel and tile surfaces the most.


OK. Fine. How about a one-second rule?

The bad news for five-second rule-lovers is that in every single one of the 128 possible combinations of surface, food, and time experimented on, the food was contaminated with bacteria immediately.

So we really do advise you not to follow even a one-second rule either.

In defence of the five-second rule, the study did show that the longer the food was on the surfaces, the more contaminated it became.

Dr Schaffner stated: ‘Although this research shows that the five-second rule is “real” in the sense that longer contact time result in more transfer, it also shows that other factors including the nature of the food and the surface are of equal or greater importance. The 5-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food.’


Train your staff

Everyone who works or volunteers in a setting that serves or prepares food or drink needs to have level-2 food hygiene training – it’s the law.

The great news for those of you feeling a bit deflated about your misguided trust in the five-second rule is that you can train yourself and your staff in food hygiene – and much more – as part of the flick subscription.

Subscribing with flick offers access to all flick courses, plus downloadable guides and resources in the flick library. So why not sign up today?


food hygiene online training



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