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.
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.
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.
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.
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!
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.
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.
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 would be 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.
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.
> 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.
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.
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.
Worth noting that this study was partially funded by the university of Waterloo
Nominative determinism.
And is on PNAS Nexus.
Nice domain name too.
> PNAS NEXUS
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.
Same attitude that prevents the urinal manufacturers from switching I reckon
Design through physics and differential equations.
This paper is Ig® Nobel Physics Prize Winner 2026 https://improbable.com/ig/winners/
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.
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.
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.
They have had these in Japan for a while now it feels like.
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.
it includes an anti-urination idea for outdoors, which may be worth noting.
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!
My stream doesn't have constant pressure throughout the process ;-)
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.
I really like the inverted version, where it's almost guaranteed to splash yourself as a deterrent.
The secret to splash free male urination is..sitting down.
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.
In a public toilet? Not happening. Back to square one.
Always carry wipes?
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?
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 would be 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.
The gents loo at a non-posh UK pub is about the lowest you can go in the western hemisphere.
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.
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.
Even women won't consistently sit down on public toilets
> 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."
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-...
Direct link to the designs (c and d, with d being practical). Great paper honestly.
https://academic.oup.com/view-large/figure/512223725/pgaf087...
It’s not much help if the aim is off
Install the urin-no next to it to help "improve" the aim.
This reminded me of some scenes in the videogame Dispatch [1]
[1] : https://static.wikia.nocookie.net/dispatch/images/c/ca/Dispa...
> 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.
Just pee in the sink
Somebody tell Larry David about this
No defecation allowed
https://en.wikipedia.org/wiki/Urinal_target
The previous design was piss-poor
Piss-rich?
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?
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.
Water and chemicals spent on cleaning. Less splash means less cleaning.
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...