What does Arlington Cemetery use to clean headstones?

What does Arlington Cemetery use to clean headstones?

Arlington National Cemetery, along with the broader National Cemetery Administration, uses D/2 Biological Solution as its standard headstone cleaner. D/2 is specifically formulated to break down biological growth — algae, moss, lichen, and mildew stains — without the harsh chemical action of bleach or acids, making it safe for marble, granite, limestone, and other historic stone materials. The process involves rinsing the stone with water first, applying D/2 to the still-damp surface, letting it sit for several minutes to break down buildup, and gently working it in with a soft natural-bristle or nylon brush — never a hard-bristled or metal brush. The stone is then rinsed thoroughly and hand-dried with a clean cloth. Notably, the goal isn’t to make headstones look brand new, but simply to remove biological staining while preserving the stone’s condition long-term.