22086
In the present study , 60 rats were daily exposed , during 28days , to oral ingestion of a mixture consisting of phenanthrene , pyrene and benzo ( a ) pyrene at 0 , 6 or 600 mu g / day .
 Chemical: phenanthrene; Chemical: pyrene; Chemical: benzo ( a ) pyrene
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: phenanthrene; Chemical: pyrene; Chemical: benzo ( a ) pyrene