In the streets of Hamburg, Germany, a new form of urban deterrent is turning public urination into an instant lesson in cause and effect. Known as “anti-pee paint,” this specialized nano-coating creates a superhydrophobic surface, repelling liquids so completely that anything touching it slides off with remarkable force. The result? Anyone attempting to relieve themselves on a treated wall experiences an immediate and unforgettable splash-back. The technology borrows from nature, mimicking the microscopic structure of a lotus leaf. Tiny ridges and air pockets prevent any liquid from adhering, meaning walls remain clean while offenders get an eye-opening consequence — all without the need for confrontation, fines, or patrols. It’s an ingenious blend of physics and human psychology: the paint doesn’t punish with authority, it punishes with instant feedback. First popularized in Hamburg’s St. Pauli district in 2015, this approach has since been trialed in other cities like London and San Francisco. While the coating is costly, city authorities note significant savings on cleaning and maintenance, and a marked decrease in repeat offenses. Beyond hygiene, it’s a striking example of how urban design and material science can work together to shape behavior. For engineers, urban planners, and city residents, anti-pee paint is both a marvel of nano-engineering and a lesson in poetic justice. The streets stay cleaner, the message is immediate, and the offender leaves with a story they won’t soon forget.
Pee sideways at an angle? Pee on the floor?
How much does that useless paint cost?? I guess it’s cheaper than installing toilets, but I bet it won’t deter a single person from peeing.
Cities: “ugh, toilets are so expensive to maintain. Remove them.”
Cities: “everything smells like piss now :(”
If there is no toilets available, a wall or a bush does the trick just fine. I ain’t going to rupture my fucking bladder because some bean counter decided to count beans.
New? Anti pee architecture has always been a thing, nanotech might be new but if you see diagonal wall attachments that’s what they are for
You know kung-fu?

Just pee directly on to the floor then.
When it rains, everyone is fucked I guess. What a stupid fucking idea this is.
- Rain is already falling, your already getting wet.
- If the rain is falling at angle sufficient enough to hit the lower section of wall, it will bounce off onto the ground, and also - re. Point #1.
You’re not very smart are you?
Someone didn’t take physics!
Mooie chemicals to leak onto the environment. This is really a pfas 2.0 waiting to happen
Yup, it’s fucking dumb and Its easily countered by peeing on the wall at an angle as well.
Or better yet, directly onto the ground beside the wall…
This is hostile architecture. Build toilets instead.
They have toilets. People are just wretched.
A lot of Europe charges to use them though, whoch i find weird. Imo they should be funded by public budgets the way libraries, school buses, roads etc are.
Like, of ya gotta pee, ya gotta pee. If you gotta pee and you don’t have any Euros on you, what else are you supposed to fucking do?? Literally what are your options at that point?
I’m sure some people would do this anyway but I suspect a lot of them can’t/won’t pay for a public toilet and aren’t close enough to a private one. It’s a UX issue
Not so much in London, and usually you need to pay for the public ones.
Yeah, people forget that people is the reason we cannot have nice things.
Just piss around a corner onto the floor. Why are people peeing on walls, anyway?
Maybe Europe should get some fucking public bathrooms.
Not looking at you, Switzerland, you’re good.
We have them. Its just that a lot of us are such fucking degenerates that we piss and shit on the toilet seats and in the urinals that no one wants to go fucking near them. Others, have are filled with blue lights, so that all the junkies cant see their veins and shoot up somewhere else.
Basically, we cant have nice things because some of us are just utter cunts. Some have been put behind a paywall, but people moaned about that as well. Basically, there are solutions, but nobody wants them because “what about the people who dont have money?”. And the answer “I guess they dont get to shit in the urinals!” is never a welcome one…
In The Netherlands, we don’t have them, but you can piss at most bars and restaurants. Still the drunk guys choose to urinate at the walls, in the plants, in the bicycles, in the stairways of parking lots. It’s gross and annoying.
I’ve heard the blue light thing before, but is it really that much of a thing? When we look for veins, I don’t even see color anymore. It’s tourniquet, squeeze, fondle your armpit, stab you.
The blue light is a thing. And its not limited to toilets in supermarkets and hospitals. Ive seen them under some bridges as well.

The issue though, like you said, is that most can find the vein by touch alone. And others are just so desperate, they try anyway. Giving exactly zero fucks about the blue light. Which has led some to question whether he blue lights are a good thing, or a bad idea thats going to eventually harm someone.
Maybe it’s because it’s still night where I am, maybe it’s because I’m on the spectrum, but those blue lights feel like an assault on my senses. I had to scroll it off my screen to type this because it made my eyes hurt. I can’t imagine having to deal with that every time I have to pee in public.
I also can’t help but wonder where people go to do their makeup. I don’t use makeup, but I often see others using the mirrors to touch up this or that. I can’t imagine blue lights are helpful in that regard.
I welcomed it in the sense I just laughed for 20 seconds
Now they pee at an angle
Like Wii Tanks, but with pee. Fun to play with your friends!
Pii Tanks?
If enough public toilets were actually provided, this would not be a problem that needs solving.
Exactly. First off, this happened 10 years ago when I still lived exactly there. It was a marketing campaign by the local “business improvement district”, i.e. the companies that basically owned half of the quarter. The main complaint of the residents was that every time the BID organized huge festivals, they didn’t provide enough public toilets. This “solution” did nothing because drunk party-goers from out of town don’t “learn” anything from this. Also, most places wouldn’t let you go to the loo on their premises if you didn’t buy anything.
But the good news is that in 2020, 2022 and last year they actually just opened new public toilets in these areas. I imagine this very confusing solution actually helped.
yeah this is actually about hating the homeless, not about making a city cleaner
While generally a promising approach, in the case of St Pauli, Hamburg it might be different. Yes there are lots of homeless people, but there are also LOTS of randoms going there to get drunk and be on their worst behavior. Its part of the spirit of that place.
Anyways “not by authority” is bs imo. An electrical fence is also “direct feedback”, or razor barbed wire and you wouldn’t dare calling those non-authority
Then they shouldn’t be pissing on walls.
Haha look, we made the man who sleeps in the alley pee on himself!
What a great world -_-
And - well I was going to say surprisingly, but its really not - the post I saw just before this was about transit use and a fear of violence. Which, of course, is ultimately due to not addressing the unhoused.
Right I’m sure the people who piss in our gateway, mysteriously every Friday and Saturday while bellowing at each other, are homeless rather than smashed out of their tiny troglodyte minds.
Hamburg has a vast number of tourists, which makes it even worse, because tourists don’t have to live in the city they’re pissing all over, nor see again the person they flashed because the fumbled pulling up their pants.
If there was a toilet right there, do you think they would still choose the wall?
If they would still choose the wall, do you think the paint is going to deter them?
How will people even know that the paint is piss-splashing paint?
Will people not immediately change their piss angle as soon as they get splash back?
If there was a toilet right there, do you think they would still choose the wall?
Have you ever been around drunk tourists before? The answer is yes
You have to keep going down the questions, don’t just stop at the first.
No, everyone is 12 now (due to willingly brain damaging themselves or being brain damaged against their will by their brain damaged parents, with stuff like atmospheric lead and unmasked COVID spread).
You have to expect people to believe whatever’s convenient for them and argue in bad faith, until each individual proves otherwise
10 drunk tourist that piss on your wall or 40 people (sober and not) that piss on your wall?
They have walked out of a club with a toilet five minutes ago. How frequently do you want there to be toilets?
The idea is that by putting the risk in people’s minds it’ll be a deterrent, or else by giving people a natural consequence (and also protecting the wall from being stained with piss) it’ll deter repeat offenders.
Oh, you mean the gross, overcrowded toilet that is typical of clubs? Weird that they didn’t want to use that. I wonder why that could be?
/sarcasm
No, just a regular toilet in a public establishment. I don’t know anyone who’s thinking “this toilet is gross, so I’ll piss in the fucking street”. I guarantee you noone is wiping down the street with anti bacterial spray.
Toilets can get busy, yet queuing for one is very normal. Have you noticed that no-one sees the queue and goes on the corner?
That’s because this is caused by drunk people failing to plan ahead and then when caught short not having any inhibitions.
Keep going down the list of questions, I’ve already accounted for other reasons why this is a dumb idea
When they piss on the piss-splashing paint, it splashes them with piss, so they stop. I believe the point is that it sprays back at all angles.
I’m not claiming it’s a magic bullet, but I am claiming that if you think this is about homeless people you are not thinking about drunk people and tourists, who are the genuine target.
Just a logistical question about how this works , does the pee reflect equally in a hemisphere normal to the surface, or does it reflect off the wall like a normal reflection.
If it is option 1, how does that work physically? Is the surface multi-faceted? Even with a hydrophobic surface I would still expect a normal reflection.
I don’t really see what’s so bad about peeing outdoors so long as it regularly rains, and you’re not peeing in a way that will affect others.
I don’t know the details, but as soon as you break up the stream it will not reflect cleanly.
Peeing in a city is always going to affect others - there will be people nearby who don’t want to see and hear it, and unless it is raining at that moment, it will leave a mess that affects people. I believe even peeing in the countryside can cause some negative effects due to nitrogen run off.
Yeah, not everything is about the homeless. Are there actually many homeless in Munich, compared to rude tourists?
Most of these are not free, according to your second link.
Not nearly enough, especially near the transit.
“The transit”? There is transit all over Hamburg and there are three directly outside the Hauptbahnhof.
If people are still peeing in the street there, then it’s not enough.
Stop making excuses. If people are still peeing on the streets they are lazy drunken degenerates.
I don’t understand how hard that is to understand for some people.
I have never met someone who’d rather piss in the streets than in a toilet if given the choice. The answer is always, always, ALWAYS “not enough free, clean, accessible toilets”
You haven’t met enough drunk people.
The answer is drunk people.
I was once walking home with a drunk housemate who pissed in the street a few minutes away from home. Also “clean” does not enter into it. The street is not clean.
A few minutes can make a difference in wet vs dry pants, especially when there’s 15 beers inside you.
Yeah, so the idea that you can have enough toilets to prevent this involves having toilets every few minutes, or every few hundred metres. That’s kind of insane. We should try the paint, or deal with the mess.
So to you it is axiomatic that the problem is insufficient toilets. You cannot understand that there are people - usually drunk - who will not use a toilet unless they are already inside it. It is not feasible to blanket a city in toilets sufficiently to eliminate public urination, so maybe a multi-pronged approach including discouraging people from doing so is more sensible.
We’ve already been doing the later. And how has that been working out?
You are correct, that I cannot understand something that I’ve never seen, or even heard of. I’ve seen shitfaced people stumble into restrooms pretty frequently. I’ve never seen someone say “I know there is a toilet less than a block from here, but I’d rather piss on the wall!”. But I hear the opposite all the time: “Man, I wish I didn’t have to piss out here, but the nearest toilet is a mile away”.
It is not feasible to blanket a city in toilets sufficiently to eliminate public urination…
Citation needed.
I have been walking home with someone who pissed in the street less than a block (I don’t live in the US, we don’t have blocks, but it was a couple of minutes) away from home.
Cmon, use that imagination of yours to go beyond what you have directly experienced.
Remember too that all drunk people have come from somewhere with a working toilet, because places that serve alcohol have toilets.
Maybe the place was closing. Maybe they didn’t need to go at the time. Maybe the toilet didn’t work. Maybe they just pee a lot. Guilty as charged.
Maybe.
All of this means that your proposed method requires toilets every couple of hundred metres between city centres and suburbs. That sounds like a ridiculous waste of resources.
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This is what we do instead of creating a better world.
We engineer hydrophobic paint to stop people from peeing on a wall…
This is creating a better world you dummy
On the downside, we’re not building a better world, but on the plus side, we at least have more PFAs than we did before!
I’d argue that keeping piss off of walls is making the world a better place, no? Especially in a high traffic area in dense European cities, the smell can be quite strong
But you do know that you can just not piss up against a wall, and just piss on the ground… right? Or better yet, make a game of it, and piss on the wall at different angles. You and your mates playing piss wars against the wall and trying to avoid each other splashback would be of interest to a lot of pissheads on the way home after finishing the kabab.
Couldn’t they just… have some (more) public toilets, or have any existing public toilets open for more hours?
In my unsubstantiated opinion, those who pee on walls don’t bother looking for a public toilet.
As a person with an irritable bladder. 90%+ of the time a public washroom or easily accessible washroom would be preferred and would stop me from peeing on random shit.
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Does that really work? I get the impression that people would go pee on that wall just to see it bounce.
Let’s scientifically try for an side angle, at which there is no measurable peeback effect any more.
Great, now we need to invent piss retroreflectors
Nice. It would be like in India where they turn to put up some metal crates to stop rickshaws from driving there, but cars could.
Workaround: wider wheels on the rickshaws, or modifying the distance of the wheels to fit said crates. People always find a workaround.
Or they just ride over the grates on a angle.
It works. I’ve seen videos, UK i think, where they used this stuff and then recorded what happens. The urine immediately sprays back at the urinator. They stop because they don’t want pee all over their pants and shoes.
It’s probably just a teflon spray on coating that prevents the pee from soaking into the wall. The rest is marketing.
If we ripped the car sewers out of our streets we could probably have enough green space that it would just, ya know, soak in. But go ahead and spend public money on technogimmicks I guess.
we could at least have plenty of public toilets in the freed up space
The streets shall run yellow… WITH JUSTICE!
Or just yellow, as everyone takes a big step back and pisses directly on to the ground… Now paint the ground, and we can all have a laugh every time it rains lol.
The ground is just concrete not painted duh


















