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: Similarly , when the P450 - mediated metabolism of lindane was blocked by cobalt chloride incidence of convulsions was increased in animals treated with lindane indicating that lindane per se or its metabolites formed by PB or ethanol inducible P450 isoenzymes are involved in its neurobehavioral toxicity .
### Output Text:
Similarly , when the P450 - mediated metabolism of <span class="chemical">lindane</span> was blocked by <span class="chemical">cobalt chloride</span> incidence of convulsions was increased in animals treated with <span class="chemical">lindane</span> indicating that <span class="chemical">lindane</span> per se or its metabolites formed by PB or <span class="chemical">ethanol</span> inducible P450 isoenzymes are involved in its neurobehavioral toxicity . 