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.
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.