10671
Cell viability decreased at the higher concentrations of the Cu salts and CuO was more toxic compared to CuSO4 .
 Cu salts, CuO, CuSO4
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Cu salts, CuO, CuSO4