There are many mysterious things in life — but there are a handful that would be missed if not pointed out. For instance, why are public toilet seats shaped like a U, while private ones are O-shaped? Were you even aware of the disparity until this very moment?

What’s up with the gap?

The U shape of public toilet seats is known as an open-front toilet seat. It’s basically required for public restrooms under the American Standard National Plumbing Code. The code was created in 1955 and further reinforced by the 1973 Uniform Plumbing Code put in place by the International Association of Plumbing and Mechanical Officials (IAPMO).

The code states: “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.”

Why, you ask? Well, it all comes down to hygiene.

For the ladies

Both of the plumbing rules rationalized that if there’s an open front on public toilet seats, it’s less likely that your private parts will come into contact with germ-ridden ceramics.

Moreover, the public toilet seat was designed with women in mind. Lynne Simick, the senior director of code development at IAPMO told Slate that the U-shaped seat “allows women to wipe the perineal area after using the toilet without contacting the seat.”

Also, it’s less likely for men to spray the actual seat while they’re doing their business, though it’s widely known that this isn’t always the case.

So, now you know the story behind public toilet seat shapes. Perhaps now you’ll feel compelled to get a U-shaped throne for your home toilet, because since when do family members have less germs than strangers?

Bonus: A toilet seat that detects heart failure

Marketed by an RIT-backed startup called Heart Health Intelligence, and currently undergoing FDA review, this smart seat will be purchased by hospitals and sent home with patients.

The toilet seats measure electrical and mechanical activity within the heart, monitoring heart rate as well as blood pressure and oxygenation.

It also measures the patient’s weight and stroke volume (the amount of blood pumped out of the heart at every beat). The device analyzes the data and sends reports to cardiologists so they can decide on further treatment.

The aim of the smart seat: to cut back on the number of patients readmitted to the hospital by heading off problems before they become acute.

“Typically, within 30 days of hospital discharge, 25% of patients with congestive heart failure are readmitted,” said HHI CEO Nicholas Conn in a press release. “After 90 days of hospital discharge, 45% of patients are readmitted. And the Centers for Medicare and Medicaid Services is penalizing hospitals for readmitting patients for heart failure.”

Conn pointed out that just the penalties for readmitting 150 patients is about $500,000 per year. By contrast, the total cost of providing 150 patients with monitored toilet seats would be $200,000.

Watch this

How to care for loved ones from a distance