Removing graffiti from bridge pillars and other structures can be an arduous and sometime hazardous process, especially when using sandblasting equipment to scour concrete surfaces clean. That’s why the Indiana Department of Transportation is now using dry ice instead.

[Above photo by INDOT]

Compared to traditional scouring methods using salt or sand to remove graffiti, INDOT found that “dry ice blasting” provides a safer and more eco-friendly alternative.

Sandblasting, while effective, can generate significant amounts of dust and debris, the agency noted. Dry ice blasting, on the other hand, works by shooting small carbon dioxide pellets at surfaces at high speeds that evaporate on impact. 

[Editor’s note: The video below shows how dry ice blasting is used in the manufacturing sector as a cleaning method for various types of metal machinery.]

Developed in-house by INDOT employees, the agency said its dry ice blasting method for graffiti removal increases safety for workers by eliminating dust and particles they might breathe in; leaves no residue behind due to the dry ice evaporating on impact; increases efficiency and saves time by eliminating the need for cleanup; and minimizes the impact on the environment and waste production.