Inventories, other than inventories held for trading purposes, are stated at the lower of cost and net realizable value. Cost is determined by the first-in
first-out method and comprises direct purchase costs, cost of production, transportation and manufacturing expenses. Net realizable value is
determined by reference to prices existing at the balance sheet date, adjusted where the sale of inventories after the reporting period gives evidence
about their net realizable value at the end of the period.
Inventories held for trading purposes are stated at fair value less costs to sell and any changes in fair value are recognized in the income statement.
Supplies are valued at cost to the group mainly using the average method or net realizable value, whichever is the lower.