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: Based on clinical data , indicating that chloroacetaldehyde ( CAA ) is an important metabolite of oxazaphosphorine cytostatics , an experimental study was carried out in order to elucidate the role of CAA in the development of hemorrhagic cystitis .
### Output Text:
Based on clinical data , indicating that <span class="chemical">chloroacetaldehyde</span> ( <span class="chemical">CAA</span> ) is an important metabolite of oxazaphosphorine cytostatics , an experimental study was carried out in order to elucidate the role of <span class="chemical">CAA</span> in the development of hemorrhagic cystitis . 