Not likely. Procyon is a high pH phosphate based cleaner. This should not harm travertine or marble. Since stone is natural, each slab is a bit different. It is always best to test a small are if you are ever unsure. Scott Warrington
Scott was saying the sodium content in Procyon is a filler, and its actually the Phosphates that do the cleaning. So why do dish detergent companies advertise "phosphate free" product? Are phosphates bad? For us or the enviornment? The listed ingredient in Procyon is Phosphoric Acid. Up until now I was referring to Procyon as a "sodium based" cleaner, but I agree with Scott that it should be called a "phosphate based" cleaner.
