8612
Since conflicting data exist on the possible risk of several lipid peroxidation products for humans , we have selected four of them , namely acrolein , crotonaldehyde , 4 - hydroxy - hexenal ( 4 - HHE ) and 4 - oxo - 2 - nonenal ( 4 - ONE ) .
 Chemical: acrolein; Chemical: crotonaldehyde; Chemical: 4 - hydroxy - hexenal; Chemical: 4 - HHE; Chemical: 4 - oxo - 2 - nonenal; Chemical: 4 - ONE
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: acrolein, crotonaldehyde, 4 - hydroxy - hexenal, 4 - HHE, 4 - oxo - 2 - nonenal, 4 - ONE 
Answer:
 Chemical: acrolein; Chemical: crotonaldehyde; Chemical: 4 - hydroxy - hexenal; Chemical: 4 - HHE; Chemical: 4 - oxo - 2 - nonenal; Chemical: 4 - ONE