CPV code 24313100 designates Sulphides, sulphites and sulphates in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
24313100 sits under 24313000 (Sulphides, sulphates; nitrates, phosphates and carbonates) and groups 2 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.