3399
We have proposed that 1 , 3 - butadiene metabolites be so tested as a reality check on the epidemiological reports .
 Chemical: 1 , 3 - butadiene
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: 1 , 3 - butadiene