Spray Bottle

D/2 Biological Solution is a professional‑grade, biodegradable cleaner formulated to safely remove mold, mildew, algae, lichen, and environmental pollution from stone, masonry, and historic surfaces. It contains no bleach, salts, acids, or solvents, making it safe for use on marble, granite, limestone, and other materials commonly found in cemeteries and historic sites. Trusted by conservators and used on national landmarks—including those maintained by the National Park Service—D/2 is the industry standard for monument and headstone care. Not Forgotten Preservation uses D/2 in our restoration work because it delivers reliable, preservation‑safe cleaning results while protecting the integrity of historic stones.