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: The pulmonary toxicity of amiodarone is thought to result from direct injury related to the intracellular accumulation of phospholipid and T cell - mediated hypersensitivity pneumonitis .
### Output Text:
The pulmonary toxicity of <span class="chemical">amiodarone</span> is thought to result from direct injury related to the intracellular accumulation of phospholipid and T cell - mediated hypersensitivity pneumonitis . 