14895
We aimed to investigate the combined effect of organochlorine pesticides heptachlor ( HEP ) and hexachlorobenzene ( HCB ) by using a medium - term rat liver bioassay .
 Chemical: organochlorine; Chemical: heptachlor; Chemical: HEP; Chemical: hexachlorobenzene; Chemical: HCB
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: organochlorine; Chemical: heptachlor; Chemical: HEP; Chemical: hexachlorobenzene; Chemical: HCB