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: We provide experimental data suggesting PCC to be an effective acute treatment for W - ICH in terms of reducing hemorrhagic blood volume .
### Output Text:
We provide experimental data suggesting <span class="chemical">PCC</span> to be an effective acute treatment for W - ICH in terms of reducing hemorrhagic blood volume . 