19156
Hydrogen peroxide is a major component of oxygen metabolism in biological systems that , when present in high concentrations , can lead to oxidative stress in cells .
 Chemical: Hydrogen peroxide; Chemical: oxygen
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: Hydrogen peroxide; Chemical: oxygen