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.
If enough public toilets were actually provided, this would not be a problem that needs solving.
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?
You can’t build public toilets every 50m and make sure it stays clean. Anything further than 50m and a drunk person will just piss to the next wall/bush/corner as they can’t be bothered with finding a proper restroom in many cases. Its not as simple as you make it out to be.
Great, now keep going down the questions I posed.
The point I’m making is that this paint won’t do a thing except cost money.
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.
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.
I’m not claiming it’s about homeless people, it just seems like a waste of money to me, and it fails to address the issue of people not having a place to piss.
The paint is merely hydrophobic, all you have to do is piss at an angle and you’ll be fine. It’s not a piss retroreflector. It’s akin to pissing on a waxed surface.
Well, they claim that statistically the problem became less severe, so maybe it does work
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.
I suppose we will have to agree to disagree. I don’t think it always affects others if you do it in private in a place where people don’t walk, and rain can hit it.
Everything has an effect, especially if lots of people do it. You do not want to pee within 100 ft of a stream if you can help it. It is better to let the pee break up in the soil. The real problem for ecology is the salts in urine. That’s why if a dog pees in the same spot every time, plants die.
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
Guys really don’t care, less so the more they drink. Wall is more convenient than a toilet around the block whether it’s sparkling or not.
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.
Yeah, not everything is about the homeless. Are there actually many homeless in Munich, compared to rude tourists?
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.
How many are enough?
https://allinmap.app/en/map/toilets/hamburg?visible_marker=toilet
https://www.stadtreinigung.hamburg/stadtsauberkeit/oeffentliche-toiletten/
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.
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.
Stop making excuses. If people are still peeing on the streets they are lazy drunken degenerates.
i’ve seen more studies saying the answer is more free toilets that i’ve seen everyone is just lazy degenerates. in fact. i haven’t seen any studies that concluded everyone is just lazy degenerates. maybe i’m reading the wrong studies?
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”.
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.
Most of these are not free, according to your second link.
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