EPA 8040A Phenol-Calibration Mixture S-4238 23 Components, 1mg/mL in isopropanol 4-Chloro-3-methylphenol 2-Chlorophenol 2-Methylphenol 3-Methylphenol 4-Methylphenol 2-Cyclohexyl-4,6-dinitrophenol 2,4-Dichlorophenol 2,6-Dichlorophenol 2