CAFFECALC is a balanced combination of phos-
phoric and citric acid which can easily remove
any contamination of limestone; it does not contain
hazardous volatile acids such as hydrochloric acid
and therefore has limited emission of fumes. It is a safe product that does not attack steel, copper, iron, bronze (it cannot be used on galvanized surfaces). On aluminum (and alloys) and zinc alloy surface blackening may occur.