Philly to Test Anti-Pee Paint


Seeking to solve complaints of occasional "human waste" on its subway system, Philadelphia is looking to test the impact of a special clear coating that not only resists urine, but repels it, spraying it back onto the guilty party instead of running down the wall.

Philadelphia is following in the footsteps of Hamburg, Germany, and San Francisco with this venture.

Southeastern Pennsylvania Transportation Authority (SEPTA) spokesman Andrew Busch told mobile news source Billy Penn that the agency would test the superhydrophobic coating this fall.

How It Works

SEPTA will be using Ultra-Ever Dry the superhydrophobic and oleophobic paint introduced in February 2013 by UltraTech International of Jacksonville, FL.

UltraTech CEO Mark Shaw demonstrated the functional properties of the company's superhydrophobic coating during a 2013 TED Talk.

According to the company, the barrier coating can completely repel almost any liquid via a "proprietary nanotechnology to coat an object and create a barrier of air on its surface."

UltraTech CEO Mark Shaw described and demonstrated the functional properties of the coating in a 2013 TED Talk. While showing how fluids would avoid surfaces treated with the liquid-repellent coating, he explained that the surface of the spray coating is filled with nanoparticles that form a “very rough and crackly surface. You think it’d be smooth but it’s actually not.”

Billions of interstitial spaces, along with the nanoparticles, “reach up and grab the air molecules and cover the surface with air,” he said. With the air essentially forming an umbrella, water, urine or any other fluid hits the layer and glides off.

In addition to its anti-wetting properties, Shaw proposes the coating has uses as an anti-icing, anti-corrosion, anti-bacterial and self-cleaning agent. In fact, Nissan was reportedly the first carmaker to apply the technology to automotive bodywork when testing its self-cleaning properties in 2014.

Effective Track Record

This is the same system employed in Hamburg's party district of St. Pauli in March 2015, where residents complained of late-night revelers who relieved themselves in public. There, a community group took it upon themselves to coat the town’s walls with the liquid-repellent coating that would splash the stream back on the perpetrator.

Inspired by the positive effects reported in Hamburg, San Francisco officials decided to coat some of its building exteriors with the coating, as reported in July 2015.

In the St. Pauli section of Hamburg, Germany, a community interest group applied the superhydrophobic coating to walls in the party district to deter public urination.

In August, San Francisco’s Bay Area Rapid Transit applied the fluid-repelling coating to 80 of its elevators, Billy Penn added. While SEPTA has not yet identified where its trial evaluations will be conducted, Busch did say that the coating would be used in a manner that is the “same as or similar to” what was done in those cities.

The coating reportedly carries a price tag of about $550 to coat 65 square feet, but the paint becomes more economical when compared to the cost of sending out workers to steam clean the areas multiple times a year, according to officials in San Francisco.

Cleanliness vs. Access

As in most cities, public urination is a crime that carries fines ranging from tens to hundreds of dollars, but those penalties often do little to deter offenders. City and transit officials hope use of the coating will make perpetrators think twice.

And while subway riders and city residents are pleased with the possibilities, not everyone is a fan. Technology site Gizmodo, for example, suggested that use of the paint is “misguided, and almost cruel.”

In San Francisco, signage warning people not to use walls as a restroom do not clearly state what the consequences of doing so are, and not all treated walls are labeled in Hamburg.

“Ostensibly, the majority of subway urinators are homeless people who don’t have access to restrooms,” Gizmodo stated.

“Hopefully, SEPTA will put up clear signage warning people the paint is there, so a homeless person wouldn’t have to endure the added humiliation of accidentally urinating on themselves.”

Those of the same mind feel the money going toward special coatings could be better spent on installing more public bathrooms.


Tagged categories: Antibacterial coatings; Coatings Technology; Coatings Technology; Corrosion resistance; Paint application; Public spaces; Public Transit; Self-cleaning coatings; Water repellents; Water-resistive barrier

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