It’s a cause of arguments in households around the world.
And over 150 years since the toilet roll was invented, the question of how exactly it should be oriented still triggers furious debate.
In the ‘over’ position, the next square of toilet paper is facing the user, while in the ‘under’ position, the next square of toilet paper is facing the wall.
Now, a scientist has settled the debate once and for all.
Dr Primrose Freestone, professor of clinical microbiology at the University of Leicester, says the ‘under’ orientation is actually safer and more effective, despite the image in the original toilet paper patent.
The researcher points out that the ‘over’ method requires a second hand to touch the toilet roll.
This increases the risk of the paper being contaminated before it reaches our nether-regions – which in turn means greater risk of infection.
‘There is more handling of the toilet roll from the over position,’ Professor Freestone told MailOnline.
Should toilet paper be hung in front of (over) or behind (under) the roll when it is placed parallel to the wall? A scientist has given the definitive answer
Dr Primrose Freestone, professor of clinical microbiology at the University of Leicester, says the ‘under’ orientation is actually safer and more effective (file photo)
Imagine you are on the toilet doing your business, and the toilet roll is in the ‘over’ position (with the next square facing you).
In this scenario, you need to use one hand to hold the toilet roll to stop it from rotating forward, and the other hand to actually tear off the next bit of paper.
In contrast, in the ‘under’ position, you can pin the next sheet against the wall with one hand as you simultaneously tear it off, according to the academic.
So you don’t have to use the second hand in the process at all – and the overall risk of transferring hand bacteria to the paper is reduced.
Especially for women, accidental transfer of bacteria from the hand to the genital area can increase the risk of infection.
And women generally tend to use more paper for men – for number ones and number twos.
‘For the under position, there is less likely to be whole roll contamination,’ Professor Freestone told MailOnline.
‘You can pin the sheets against the toilet wall without having to touch the exterior of the roll.’
Professor Freestone advocates not using a second hand in the process of wiping at all if possible, to avoid the spread of bacteria (stock image)
When people enter the bathroom, both hands are immediately exposed to high-touch surfaces likely teeming with harmful bacteria – including the doorknob and the toilet seat.
So by touching the paper with just one hand instead of two, we are potentially halving the risk of bacterial transfer from the hand to the unused toilet paper.
Of course, both hands have the potential to transfer bacteria onto toilet paper during a bathroom break – but by only using one hand throughout the whole process, we can reduce the risk of this transfer.
Also, using two hands risks the spread of bacteria from the wiping hand to the other hand – because they are brought into close proximity to each other.
‘If someone who has wiped say once and the faecal matter has soaked through the layers of toilet paper and makes hand contact, the presumably right hand that did the wiping will likely be contaminated,’ Professor Freestone said.
‘Then that right hand may contaminate anything it touches as the toilet user reaches for more toilet paper which they then fold for wipe two, possibly touching the left hand as it does so.’
According to Professor Freestone, her advice is even more pertinent in public toilets, where there may be multiple sites of heavy faecal contamination all over the toilet door, stall and seat.
‘This is why it is so important to wash your hands after going to the toilet, and not to eat, drink or use a phone in the toilet, either,’ she told MailOnline.
Dated 1891, a drawing for US Patent No. 465588A (left) features a toilet roll clearly positioned unmistakably in the over orientation
Interestingly, the original patent for toilet paper more than 150 years ago shows a toilet roll in the over, not under, position.
The patent from September 15, 1891 was filed by the inventor of perforated toilet paper sheets, New York business man Seth Wheeler.
According to various surveys, around 70 per cent of people prefer the over position and 30 per cent the under position.
There’s also the argument that the under position reduces the chances of a cat or small child from pulling at the toilet paper.
But the over position does have alleged advantages, such as giving you more transparency over how many square you are tearing off.
