Gross reason why some public toilets have U-shaped seats

You may or may not have noticed that public toilets can differ, with some having full seats and others having more of a 'U-shaped' seat for your rear end.

Rather than some seats just having a chunk missing, it turns out there is a reason why some are different and it all comes down to health and hygiene.

Whilst there are many questions around toilets, including what happens if you don't close the lid before flushing (it's pretty grim), why you shouldn't sit on the toilet for longer than ten minutes as well as the bad habits we should not be doing according to doctors, one question that has come up is why a U-shaped toilet seat was invented and used.

Some toilet seats are fully round, and others are not and there's a reason behind this. (Getty Stock Photo)

It's been just over 50 years since the U-shaped toilet seat became more widely used, with the American Uniform Plumbing Code bringing it in from 1973.

This code for toilets goes back nearly 70 years to 1955 when it was first created, and essentially sets the standard of hygiene expected in public restrooms.

The U-shaped seat in public restrooms is a requirement of IAPMO’s Uniform Plumbing Code and whilst you won't find yourself in court if you don't follow it, it's still widely adopted across most states and cities.

The code says: "Water closets shall be equipped with seats of smooth non-absorbent material. All seats of water closets provided for public use shall be of the open-front type."

The design of the U-shaped toilet seat does also come with a bit of thinking behind it, as it's meant to be more suitable for women using the loo.

The idea being that women can reach down to clean without having to touch the seat, where most of the germs would be lurking.

Lynne Simnick, senior director of code development at the International Association of Plumbing and Mechanical Officials, told Slate that the open seat was designed to let women 'wipe the perineal area after using the water closet' without using a seat that might be unhygienic.

She added that the open-front seat 'eliminates an area that could be contaminated with urine', while it also 'eliminates the user’s genital contact with the seat'.

The U-Shaped toilet seat is part of the American Standard National Plumbing Code.(Getty Stock Photo)

Dr. Roshini Raj, a gastroenterologist at NYU Langone has previously explained the risks of the toilet as she shared: "I see a lot of people who get food poisoning or catch different things by not having good hygiene practices in the bathroom.

"I just think generally speaking, if you’re on the toilet having a bowel movement or trying to have a movement, you shouldn’t be using your fingers on anything else."

There's also thought to be an ergonomic factor in the U-shaped seat, meaning it's designed to suit our bodies. Yet the science and theory on that seems somewhat loose, with little measurements or guidance provided.

Whilst most bathrooms now will have the U-shaped seat, there are exceptions according to the Uniform Plumbing Code requirement.

This includes that if a public restroom has an automatic toilet-seat cover dispenser, the seat doesn’t need to be U-shaped.