The Myth of the Five Second Rule
It’s being bandied about that that a recent survey from the Food Standards Agency identified that 27% of respondents believed in the five second rule – in other words, they thought that it was OK to eat food that has fallen on the floor if it had only been on the floor for a few seconds.
When I was working on the BBC Rogue Restaurants series, where secret filming took place in restaurants, we saw plenty of evidence of food being dropped on the floor and then picked up and served to customers, much to the disgust of the audience. Caterers referred to the “five second rule” in authoritative tones.
I am quite frequently asked whether this is an issue – could contamination from the floor get onto food in a few seconds? Well the scientific answer is that yes, contamination can be transferred instantly, and it doesn’t matter how long the food is on the floor!
Dr Ronald Cutler, a microbiologist from Queen Mary College, University of London carried out some testing of foods to see whether they could be contaminated by E. coli if they were dropped onto a surface artificially loaded with E. coli. Using pizza, apple and buttered toast on different surfaces. Dr Cutler analysed the food samples and found that they were all covered in germs compared with control samples that had not been dropped. The samples were dropped on the contaminated surfaces and picked up after zero, five and 10 seconds. Even after zero seconds each sample tested was heavily contaminated. Other research has also been carried out and has found the same thing – in other words, the five second or three second rules are myths: as soon as food drops on the floor then it will become contaminated however long it stays there for.
This is of course particularly important for ready to eat foods that may not be further cooked. A piece of raw chicken, already likely to be coated in Campylobacter or E. coli, would be less of a risk if dropped on the floor than a piece of cooked ham, for example, although of course it could still pick up dirt and any contamination on the floor.
So if food drops on the floor, the message is to bin it and don’t count the seconds – it’s pointless.