PVC primer prepares PVC surfaces for PVC cement welding—typically pipe fitting—via solvents that clean away dirt and debris from the PVC. The primer then dissolves/etches the top layer of each surface to make room for cement application. PVC primer comes in two primary forms—clear and with purple dye. Although either can discolor/stain concrete by trapping dirt or dye into the concrete surface, removing a stain caused by PVC primer isn't impossible as long as you use another solvent to break up and pull away the trapped dirt and dye.
Put on your safety goggles, NIOSH multipurpose safety or vapor protection mask, and gloves. PVC primer and the chemicals used to clean it from concrete contain solvents that can cause bodily injury—not only eye and skin irritation, but also organ failure and damage to the upper respiratory system and nervous system.
Open windows and doors if removing PVC primer from concrete inside your home to reduce vapor build-up.
Pour an acetone-based nail polish remover on a cloth.
Blot your PVC stain(s) with the wet cloth. The acetone, a solvent, should dissolve the PVC primer and/or purple dye in the primer. Repeatedly blot and add additional nail polish remover as needed until the stain fades.
Scrub your concrete with water and detergent using a soft-bristled brush. Soak up the dirty water with a cloth or mop. Rinse your concrete surface, then air dry.