The CRM BAM-U117 represents a mixture of a sandy soil collected from a contaminated
former gasworks area in the Berlin region (Germany) and an unpolluted sandy soil from
Nalaikh region (Mongolia). The raw materials were dried at ambient air to constant mass,
and afterwards the fractions passing a 2 mm screen were ground to particle sizes below
125 µm. Before bottling, the two fractions were mixed and homogenised.