In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: As wider use confirms their safety profile , they will gain increasing importance in the therapeutic approach to hypercholesterolaemia and its consequences .
### Output Text:
As wider use confirms their safety profile , they will gain increasing importance in the therapeutic approach to hypercholesterolaemia and its consequences . 