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: These data indicate that a critical percentage of NTE inhibition in brain and spinal cord sampled shortly after Mipafox exposure can predict neuropathic damage in rats several weeks later .
### Output Text:
These data indicate that a critical percentage of NTE inhibition in brain and spinal cord sampled shortly after <span class="chemical">Mipafox</span> exposure can predict neuropathic damage in rats several weeks later . 