Manila is one of the world’s most polluted cities, with air pollution levels above the safety standards set by the Clean Air Act. The need for more trees has never been greater. However, it takes more than ten years for one tree to become mature enough to clean the air. On top of that, there is virtually no more room in the city for trees to grow.
Boysen, the Philippines’ leading paint brand, has a solution–KNOxOUT, a revolutionary smog-eating paint. KNOxOUT contains CristalACTiVTM photocatalytic technology that uses ultrafine titanium dioxide to absorb energy from light and destroy harmful nitrogen oxides in the air. One square meter of Boysen KNOxOUT painted surface cleans as much nitrogen oxide as one mature tree.
These Squares Clean the Air
Boysen and its creative agency, TBWA/SMP effectively turn walls into trees by using KNOxOUT to paint one-square-meter artworks along Manila’s busiest and most treeless highways.








The latest mural is along E. Rodriguez Avenue C5, Pasig. The artwork consists of striking and colorful portraits of rubber ducks, birds, food, toys, and other objects. But because they were painted with air-cleaning KNOxOUT paint, each one was, indeed, a tree.
To date, over 6,000 square meters of the city’s walls have been painted using Boysen KNOxOUT. Everyday, the artworks reduce the air pollution by 20%.