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: Aspirin or salicylate ingestion had occurred in only one of the 20 cases ( 5 % ) , and paracetamol ( acetaminophen ) had been administered in only six of the cases ( 30 % ) .
### Output Text:
<span class="chemical">Aspirin</span> or <span class="chemical">salicylate</span> ingestion had occurred in only one of the 20 cases ( 5 % ) , and <span class="chemical">paracetamol</span> ( <span class="chemical">acetaminophen</span> ) had been administered in only six of the cases ( 30 % ) . 