2763
Each rat was then injected with alfentanil ( ALF , 0 . 5 mg / kg sc ) .
 Chemical: alfentanil; Chemical: ALF
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: alfentanil; Chemical: ALF