Aluminium chlorohydrate is a group of salts having the general formula AlnCl(3n-m)(OH)m. It is used in deodorants and antiperspirants and as a flocculant in water purification. In water purification, where it is usually called polyaluminium chloride, this compound is preferred in some cases because the pH value can be varied according to the exact values chosen for the subscripts n and m in the pattern formula. Although many variations are used, an especially important combination is Al12Cl12(OH)24. The actual pH correlates to the formula m/(3n).