(NEXSTAR) – The bathroom: It’s a place where many an inquisitive mind has contemplated the great mysteries of the universe. And if it’s a public bathroom, it’s also where one of the great mysteries of the universe can be observed. Open-front toilet seats — sometimes referred to as “U-shaped” or “split” seats — are almost exclusively affixed to toilets in publicly accessible bathrooms or commercial spaces. But they’re never the norm in private residences, where the closed (O-shaped) seats are standard. Unusual toilet placement in $2M home perplexes the internet Theories as to why this is the case abound on social media. Some of the more common arguments found on internet forums pertain to hygiene — e.g., the open-front seats reduce the chances that a user’s more sensitive body parts will make contact with the toilet, or that their urine will splash or drip onto that area. Others believe it’s more about comfort, and claim that roomier public bathrooms are generally large enough to accommodate a more ergonomic seat, which may offer “more give” or accommodate a larger variety of users than a seat at a smaller private bathroom that isn’t used as frequently.    “I actually like the U-shaped seats that they have at work more than the O-shaped one I have at home,” one commenter wrote in response to a Reddit user who argued for ergonomics. Some, too, have theorized that open-front seats are more cost-effective to produce, clean or maintain since they have less surface area — with one claiming that urine, or specifically uric acid, would eventually eat away at the front part of a closed-front seat — but that wouldn’t explain why they’re not installed more frequently in people’s homes. (Getty Images) Even still, some of the arguments seem plausible enough to hold water. But the one that makes perhaps the most sense — the seats were designed with hygiene in mind — is the official explanation provided by the International Association of Plumbing and Mechanical Officials (IAPMO). In a statement obtained by Nexstar, Hugo Aguilar, P.E., the senior vice president of Codes and Standards at IAPMO, said the open-front seats reduce the chances that germs or bacteria will spread from person to person. “Open front seats and elongated toilet bowls for public restrooms minimize the risk of the user coming in contact with possible contamination from a previous user,” Aguilar said. Furthermore, Lynne Simnick, the director of Code Development for IAPMO, once told Slate that the seats allow for easier wiping after seated urination, in that they reduce the chances that someone’s hand will touch the seat. The same explanation has been offered by the American Society of Plumbing Engineers, which added that open-front seats help prevent contamination with urine, as well as “genital contact with the seat.” In its email to Nexstar, the IAPMO also noted that elongated toilet seats with open-fronts (or seats with automatic seat-cover dispensers) are actually a requirement for public restrooms under Section 411.3 of the IAPMO’s Uniform Plumbing Code, which is why the U-shaped seats are so ubiquitous. A representative for the IAPMO, however, noted that not all regions of the U.S. are governed by the same plumbing code, which is part of the reason why public bathrooms sometimes have O-shaped seats. Morning showers vs. nighttime showers: Which is better for your health? With that now settled, America’s most inquisitive minds can finally put the subject to rest and instead focus on some of the universe’s other great mysteries, like the purpose of mankind’s place in the universe, or why some boxes of wet wipes say “flushable” on the package, when they are indeed anything but.