sentences:  These "soft" abrasives are also used to avoid damaging the underlying material such when cleaning brick or stone, removing graffiti, or the removal of coatings from printed circuit boards being repaired.Sodablasting uses baking soda (sodium bicarbonate) which is extremely friable, the micro fragmentation on impact exploding away surface materials without damage to the substrate.Additional synthetic abrasives include process byproducts (e.g., copper slag, nickel slag, and coal slag), engineered abrasives (e.g., aluminum oxide, silicon carbide or carborundum, glass beads, ceramic shot/grit), and recycled products (e.g., plastic abrasive, glass grit).