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The five-second rule is a uni­ver­sally recog­nised prin­ciple of com­mon sense, which states that if food falls on the floor and is retrieved with­in five seconds, it can still be safely eaten.

I went to board­ing school, so my stom­ach is immune to most known bac­teria and many of the ele­ments found on the peri­od­ic table. I am also incred­ibly lazy, so not only do I abide by the five-second rule, some­times if food falls to the floor I’ll just slide out of my seat and eat it where it lands.

Even hav­ing kids hasn’t den­ted my faith in the rule. They will hap­pily pick up saus­ages or sand­wiches or chick­en bites from the floor and chuck them in their respect­ive gobs. Mind you, they’ll eat fridge mag­nets and fire­wood too, if I’m not pay­ing attention.

To date, sci­ence has, in gen­er­al, pooh-poo­hed the fool­ish, ill-edu­cated pub­lic and our gen­er­ally held belief in the five-second rule. Recently, how­ever, hope has blos­somed like Sta­phyl­o­coc­cus on pastry with find­ings by Aston Uni­ver­sity in Eng­land. Trust the Eng­lish to laugh in the face of food quality.

The university’s School of Life and Health Sci­ences found that there is min­im­al bac­teri­al trans­fer from floor to food with­in the allot­ted five seconds, but much more if you leave the food there for 30 seconds or longer. They also found that the amount of bac­teria food will attract increases dra­mat­ic­ally when the food in ques­tion is, and I’m quot­ing here, “moist”.

To both of these pub­lished, expens­ive, sci­en­tific­ally reached con­clu­sions, allow me to say, “Well, duuuuh.”

The Aston Uni­ver­sity find­ings have caused quite a furore with­in the sci­entif­ic com­munity (who should prob­ably be put­ting their com­bined ener­gies into find­ing a cure for can­cer, rather than arguing about this sort of non­sense), so I decided to take mat­ters into my own hands.

From a sample of 20 care­fully selec­ted people who rep­res­en­ted a fair cross sec­tion of mem­bers of my work­place and social group, each of whom answered a ques­tion­naire when they were in a hurry, the find­ings were rel­at­ively con­clus­ive. All bar two (90 per­cent) admit­ted that they have adhered to the five-second rule ‘more than once’. That num­ber was cut to nearly half when the word ‘often’ was added, and only two people were brave enough to front up with ‘almost always’. The most sig­ni­fic­ant dis­cov­ery of my own sur­vey, how­ever, was that the rule’s legit­im­acy is entirely depend­ent on situation.

Stat­ist­ic­ally speak­ing, almost all of us are OK with the rule as long as three con­di­tions are met:


  • It must be your floor.
  • The food must be — at least rel­at­ively — solid.
  • The food retrieved from the floor must be your own.


In oth­er words, it’s fine to scoop up and scarf down a chick­en nug­get or a piece of toast while stand­ing in your own kit­chen. But it’s much less fine to watch the neigh­bour spill but­ter chick­en all over the floor of the res­taur­ant, drop to the ground, slop it onto your plate and then carry on eat­ing as if noth­ing has happened.

Who’s hungry?

Steve Joll

Steve works as part of the breakfast show on wellington's The Breeze radio station. In past lives he's been a sports journalist for ONE News, a presenter on iconic children's show What Now and one heck of a forecourt attendant. He has three kids: a talkative son (Theo), aged six, and twin daughters (Margaux and Lila), aged three. He adores them and yet is counting down the days until they leave home. It seems a long way off.