Splash-free urinals (2025)

(academic.oup.com)

151 points | by u1hcw9nx 3 hours ago

36 comments

  • danjc 3 hours ago
    Worth noting that this study was partially funded by the university of Waterloo
    • rigrassm 3 minutes ago
      I come here for the stories and stay for comments like these.
    • pfdietz 3 hours ago
      Nominative determinism.
    • georgefrowny 2 hours ago
      And is on PNAS Nexus.
    • asdfasvea 2 hours ago
      Nice domain name too.
    • amelius 1 hour ago
      Now I have to go.
  • dguest 1 hour ago
    Ig nobel prizes were just a few days ago:

    https://improbable.com/ig/winners/#ig2026

    Edit: The splash free urinal was the winner for physics!

    I once joked that these do more for science than Nobel prizes. Now I don't think it's a joke: "wacky but interesting" awards are more important for the advancement of science than "everyone agrees this these people should be even more famous" awards.

    • microtherion 25 minutes ago
      I wonder whether a “Ig Nobel Price Winner” sticker would provide marketing benefits for an urinal.
      • gdisk1 6 minutes ago
        Redirection of flow is greater than of more.
  • xivzgrev 1 hour ago
    I remember being annoyed by splash back in sixth grade. I mocked up an alternative design (essentially, a urinal that tilted away from you), and emailed some friends. They never responded, and I never followed up.

    Looking back I feel sad - that's the kind of curiosity to nurture in a kid. But peers are rarely the best group, it would've been better to tell my parents or the right kind of teacher. My friends also could've said something: " I don't know what to do about this but you should tell ms blah blah blah", in a serious way not mocking way.

    I'm glad someone else has finally looked at this sticky situation

    • shevy-java 52 minutes ago
      You would have been an excellent splash sputter scientist.

      > I'm glad someone else has finally looked at this sticky situation

      Wait ... your splash variants are sticky???

    • altmanaltman 1 hour ago
      I mean you're sad about a hypothetical. Why not consider the alternative where even your parents and teachers will probably not care because who wants to hear about a splash free uniral design from a kid in sixth grade. Like if some kid walked up to me with that, I would ignore them too sorry.
  • d-e-r-e-k 2 hours ago
    Global sustainability and accessibility seems a bit grandiose lol. It’s just a urinal after all. That being said, it’s been 4 years since Waterloo first determined this and it’s still unavailable to purchase. I’ve been patiently waiting for one to install in my shop but it seems like it’s not all that important for the globe if it’s still unavailable 4 years later.
    • jonhohle 56 minutes ago
      Things we take for granted, like washing hands, were pivotal in reducing illness in hospitals.

      If 50% of the population walk out of a public bathroom without tracking urine on their feet or anything else that touched the floor and custodians have 99% less bodily fluids to deal with, that seems like positive progress. Maybe it will move the needle in ways that are unexpected.

    • zdc1 1 hour ago
      I would love to see some Nautilus style urinals because--as a self-interested adult--splashback also hits me if the angle is bad enough. Sometimes I even use the stalls to avoid those porcelain tricksters entirely.
    • sfink 25 minutes ago
      There are a lot of reasons why something could get picked up, and sustainability is very low on the list. The manufacturers don't care; they get paid the same regardless of the amount of splashback. Most businesses won't care unless it significantly reduces maintenance overhead, and that's only going to happen if splashed urine is the determining factor in how frequently a bathroom gets cleaned. (As opposed to paper towels littering the floor, supplies running out, or the various disgusting things that happen in stalls.) Even if it were the determining factor, there would likely be pushback when people realize that better urinals lead to less frequent cleanings, and I wouldn't want to be the one having to justify the switch to people. And of course, if you already have a urinal, nobody's eager to buy a new one, and nobody's eager to discuss this particular topic.

      The way I would see this happening is if users insist on it. And we likely won't until we experience one of these in real life, which makes it a chicken and egg problem.

      There's also the argument that splash mats are a cheaper and even superior approach. That argument is unconvincing to me, because the ones I have experienced have been mostly ineffective, but it sounds like others' experience has been better. Maybe here in the US we just don't have very good ones? As a country, we've always been pretty bad at anything that seems gross. (Not that it's all that different in the rest of the West.) We have this naive faith in the ability of dry toilet paper to clean that which it can not, and disgust at alternative approaches that actually work. But that's a different topic. (Specifically, solids not liquids!)

    • blurbleblurble 2 hours ago
      Same attitude that prevents the urinal manufacturers from switching I reckon
  • codethief 8 minutes ago
    > The “urine-no,” a hostile antiurination surface:

    > Instead of minimising splash, it can instead be maximized by setting […], see Fig. 7a. Although not suitable as a commonly practical urinal, it showcases the design philosophy. Such a surface could be installed outdoors to deter public urination as the offender would fall prey to enhanced splash-back. This hostile surface may be dubbed as “urine-no,” as shown in Fig. 7b.

    Love it!

  • danw1979 3 hours ago
    The recent introduction, in the UK at least, of splash-back reducing urinal … mats (?) has basically solved the problem in my opinion. They’re a disposable (but not single use…) plastic freshening insert with loads of short rubber strands, closely packed.

    You can pee on one of these mats and the stream almost aerates itself on impact and you get basically no splashback, I guess with a similar mechanism to how an aerating tap produces a stream of water that doesn’t splash off whatever it hits.

    • SoftTalker 1 hour ago
      Yes this is the best solution I've seen. And every male pretty quickly figures out that the angle of the stream greatly affects splashback. Seems rather wasteful to spend money on this study for a solved/non-problem.
    • RattlesnakeJake 3 hours ago
      We've had those in the US for several years now, and they work really well.

      I did encounter an upside-down one yesterday. That was... counterproductive.

      • jkubicek 23 minutes ago
        I was on a work trip to Indianapolis last week and encountered two separate urinals with plastic screens branded by the same supplier. One screen was branded so that the plastic fingers point towards the user, one was branded so that the plastic fingers pointed towards the drain (i.e. the wrong way).

        Makes me wonder why. Was that a misprint? Did someone get confused about the correct direction for the fingers?

    • ruszki 1 hour ago
      The worst urinal which I used was in Brussels about 15 years ago, and with that "splash-back reducing" mat. And it covered every part of the inner wall of the urinal. The mat caused the exact opposite of what it was supposed to do. It made it worse, and I had to wash my shorts, because it started to smell disgusting the next day.
  • u1hcw9nx 3 hours ago
    Design through physics and differential equations.

    This paper is Ig® Nobel Physics Prize Winner 2026 https://improbable.com/ig/winners/

  • harvie 2 hours ago
    Sometimes i am using an urinal and i feel like no engineers were involved in the design. Glad to see someone is actually approaching this with proper science.

    There is more to it than the splashback tho. Sometimes it seems that the surfaces that already have splashes on them are not angled properly to lead the water to the drain. This seems to create need to have sharp edge/lip rather than round one, which might be tricky to make resilient in porcelain. But the rounded lip certainly allows for droplet flow towards the user rather than the drain hole.

    • abyssin 1 hour ago
      My pet peeve about urinals has to do with the way the separating walls are usually installed. It's systematically too low, as if their goal was to prevent splashing between each station instead of their role of visual privacy.
      • SoftTalker 1 hour ago
        Go visit an older stadium in the USA. Either no separating walls, or just a trough where you stand shoulder-to-shoulder with the people on your left and right. Eyes forward.
      • peddling-brink 1 hour ago
        > as if their goal was to prevent splashing between each station

        Frankly, this is more important to me. I’m not looking around, and if someone else does, that’s their problem.

      • basisword 1 hour ago
        I very rarely see separating walls in the UK. Are they common in your country?
  • stevetron 36 minutes ago
    I was in a Costco one, and the men's room urinal was a trough, a strainless steel trough! I thought it was 'cool'.

    What they need to do with urinal design is to make one that can catch the wide-spray of someone who sports a PA.

    I worked as a temp once in a stae government building. It didn't have enough bathrooms. The toilets were of the type that drained/fastened to the wall instead of the floor. One day, someone big sat down and broke it. There was an angry announcement on the rarely-used building-wide speaker. Nobody owned-up to it.

    • sph 24 minutes ago
      I've seen plenty of stainless steel trough urinals in the pubs and clubs in the UK, and I'm now aware this sentence reads a bit funny.
  • hbrav 14 minutes ago
    The discussions section describes a solution to the opposite problem, where you optimise a surface for high splashback to deter people from peeing on it. Whether this makes the authors Lawful Evil or Chaotic Good is a matter of personal opinion, but they're definitely one or the other.
  • geekamongus 2 hours ago
    No amount of engineering can solve the problem that no matter how much you jiggle, you shake, or you dance, the very last drop always falls in your pants.
  • ravenstine 1 hour ago
    Even if a urinal doesn't splash, there's usually (always?) a decent amount of fine droplets that eject out from the stream since the flow is rather turbulent. On top of that, the fleshy opening is never completely stable.

    What we really need is laminar flow!

    • gattr 44 minutes ago
      A custom 3D-printed user-matched disposable nozzle, perhaps? One could carry a handful in his pocket and don before the act.
  • tshanmu 17 minutes ago
    a surprising paragraph in the middle of the article "The “urine-no,” a hostile antiurination surface"
  • falcor84 3 hours ago
    > droplets which travel back onto the floor and user

    I suppose this disproves Tufte's "There are only two industries that call their customers 'users': illegal drugs and software."

  • ahoka 3 hours ago
    I really like the inverted version, where it's almost guaranteed to splash yourself as a deterrent.
  • ttul 31 minutes ago
    "Canadian who helped design splash-free urinal is proud of his weird science award"

    https://www.cbc.ca/radio/asithappens/2026-ig-nobels-9.733140...

  • walthamstow 2 hours ago
    Just aim at the sweet spot where your stream smoothly swirls into the plughole. No spray, minimal sound. Most toilets and all urinals have this spot you can hit. In Amsterdam airport they even mark it for you with a crosshairs!
    • aeyes 2 hours ago
      My stream doesn't have constant pressure throughout the process ;-)
  • y-curious 2 hours ago
    Direct link to the designs (c and d, with d being practical). Great paper honestly.

    https://academic.oup.com/view-large/figure/512223725/pgaf087...

  • masfuerte 3 hours ago
    Traditional urinals [1] are very effective. As are the steel variants [2]. The latter tend to become very grim over time.

    [1]: https://www.hlwashrooms.co.uk/healey--lord-niagara-urinals--...

    [2]: https://acornthorn.co.uk/urinals-wcs-cubicles/urinals/ur068-...

  • vintermann 1 hour ago
    > High-speed images of splash events generated by flow from an anatomically accurate nozzle

    They had some fun writing this.

  • qsera 1 hour ago
    European closets have the same issue. Indian closets does not. Actually Indian closets are superior in every way if you have good knees...
    • linkregister 18 minutes ago
      In practice a user will find the squat toilet to be superior until the user count increases above a dozen per hour. Then a single user will carelessly engage the spray hose and saturate the entire area. The area around the pit will be inundated with muddy water. Remediation requires a mop and bucket, which is likely only performed once daily.

      An anatomically inferior sitting toilet in similar settings will often be soiled by careless users. However, a conscientious user can tidy their contact surfaces with toilet paper.

      This has been my observation from my travels in the three continents I have been able to observe squat toilets in use.

  • enahs-sf 2 hours ago
    They have had these in Japan for a while now it feels like.
  • freezystem 2 hours ago
    Nice, but does it takes into account that some droplets are directly issued from the hose itself ? Not to mention the double stream problem ^u^ Cool paper nonetheless.
  • nelox 3 hours ago
    It’s not much help if the aim is off
    • consp 2 hours ago
      Install the urin-no next to it to help "improve" the aim.
  • plasma_beam 3 hours ago
    The secret to splash free male urination is..sitting down.
    • bluebarbet 3 hours ago
      In a public toilet? Not happening. Back to square one.
      • Ylpertnodi 2 hours ago
        Always carry wipes?
        • sph 22 minutes ago
          In my man-purse? Not enough space, what with the Swiss Army knife and travel can of WD-40 I'm already carrying.
      • quickthrowman 2 hours ago
        I fail to understand why anyone is scared to place their bare thighs on a public toilet seat. Do you have open wounds on your legs?
        • footydude 2 hours ago
          Can't speak for everyone but in my experience using public toilets (predominantly UK, pubs and train stations):

          * there's not always a properly functioning seat / seat at all

          * the seat is not always dry

          * the cubicles do not always have a functioning lock

          * the bowl is not always 'clear'...for reasons probably best left unexplored, people seem to choose public toilets as a place to carry out the most incomprehensible and unimaginable of all bowel movements. I've been greeted with bowls that let's just say would be benefit being assessed by a trained professional

          Public toilets are also often pretty grim places in general due to the smells, sounds and general lack of hygiene/cleanliness.

          All that said...IF the toilets look in decent repair I personally will use the cubicle and sit down, but it's probably less than 30% of toilets that feel like that's an option.

          Also just to say I am someone who always sits to pee whenever at home/in a person's home and i'm not someone who anyone would ever call a germaphobe, so I do generally choose to sit rather than stand.

          • shermantanktop 1 hour ago
            The gents loo at a non-posh UK pub is about the lowest you can go in the western hemisphere.
        • denkmoon 2 hours ago
          I don’t care if my bare thighs were coated in the most potent prophylaxis known to man, I am not sitting on another man’s piss and or shit.
          • short_sells_poo 2 hours ago
            Yeah, the issue is that it takes one disgusting degenerate who doesn't know how to use a toilet and pisses all over the seat or worse.

            I'm purposefully not calling these people uneducated, because I routinely encounter it in an environment full of highly paid and educated people with Stanford, Harvard, Princeton, etc... kind of education. These people come from money, earn money and are supposedly educated. And yet, they will happily piss all over the toilet seat and not even bother to clean it.

            Shows also that money doesn't buy class.

            • basisword 1 hour ago
              Agreed it's 100% not an education/money/class thing. I moved into a larger office, high tech company, and the number of times people need to be told not to leave the toilet in a state or to take their rubbish out of meeting rooms when they leave is eye opening. A large number of people from all backgrounds are just animals.
            • mschuster91 1 hour ago
              In the line of thinking of educated toilet shitters - why clean up after oneself when there is, from childhood, always some underpaid person of color that does the cleanup for you?
        • basisword 1 hour ago
          a) sitting on piss

          b) sitting on a seat you just wiped piss off

          c) piss on the floor which will get on your trousers if you sit

    • shermantanktop 2 hours ago
      At home? 100%. Out in the world? Very much depends.

      I was just in a stall where the inside of door had a pictogram forbidding users from standing on the edge of the bowl and squatting. I assume this might be for visitors from countries where squatting is common.

      Point being, you just never know what random members of the public will do with a door to hide behind.

    • scythe 2 hours ago
      Even women won't consistently sit down on public toilets
  • b3lvedere 3 hours ago
    This reminded me of some scenes in the videogame Dispatch [1]

    [1] : https://static.wikia.nocookie.net/dispatch/images/c/ca/Dispa...

  • shevy-java 53 minutes ago
    That takes all the fun out of using public toilets.

    One of the more interesting scientific studies was the behavioural change of when you put down the image of a fly on an urinal. These flies are suddenly targeted by strong streams as if there is no tomorrow ...

    • codethief 3 minutes ago
      Maybe an opportunity for a hydroelectric power source?
  • fedeb95 1 hour ago
    it includes an anti-urination idea for outdoors, which may be worth noting.
  • shafyy 3 hours ago
    Somebody tell Larry David about this
    • trwhite 3 hours ago
      No defecation allowed
  • asdfasvea 2 hours ago
    Sustainability?

    What resource will we run out of if we continue to piss in traditional urinals?

    Has bullshit marketing terms invaded scientific papers now as well?

    • SoftTalker 1 hour ago
      There was a trend for a while for waterless/flushless urinals to save water. Though I would guess those have higher cleaning costs so not sure how that worked out in the end.
    • bobsmooth 2 hours ago
      Water and chemicals spent on cleaning. Less splash means less cleaning.
    • vlyan 2 hours ago
      not so long ago it was very fashionable to include DEI/ESG/etc lip service in those things, regardless of whether it made sense. for example, I've read a study comparing leather tanning compounds and it had a completely out of place paragraph babbling about climate change. the author wasn't even American, it's a global cargo cult.
  • Razengan 2 hours ago
    Just pee in the sink
  • ButlerianJihad 2 hours ago
  • fguerraz 2 hours ago
    The previous design was piss-poor
  • NotRedFox 1 hour ago
    Honestly not a bad idea
  • vasco 1 hour ago
    > At Amsterdam’s Schiphol airport, the use of fly stickers to change aiming behavior resulted in a reportedly 50–80% reduction (not elimination) in splashback observed and an 8% reduction in cleaning costs

    It's surprising it's that high (8%). I would imagine it takes as long to mop a floor that has pee droplets or mop a floor that doesn’t. And someone still needs to mop the bathroom floor anyway and go into the bathroom anyway. Unless you pay the cleaners by hour instead of having them on payroll, monetarily I don't see the difference.

    I expect cleaning costs to be dominated by the long tail, ie every bathroom cleanup job being the same except for the odd time when someone threw up on the floor or sprayed poop on the walls or what have you.

    Still nice to not get pee on yourself though, that part is good.

  • manarth 3 hours ago
    TLDR: The "Cornucopia" has the least amount of splashback, however the "Nautilus" is the recommendation of choice, to accommodate ease of cleaning and variations in the height of the user.

    https://academic.oup.com/pnasnexus/article/4/4/pgaf087/80987...