Benchmark Ambient Concentrations and Associate De Minimis Values

De Minimis Cancer Risk Chronic Noncancer RiskLb/Ave C/ BAC Basis of BAC BAC Ave Basis of BACC NCC NC5 4 3 3Lb/Yr NC µg/m µg/mChemical CAS No. Period Lb/Hr Source Date Period Type Source DateCategory 1 TACs1 Acrylonitrile 107-13-1 7.20 0.008 C 0.015 IRIS 1/1/1991 2 Annual RfC IRIS 12/1/199112 Arsenic and arsenic compounds 7440-38-2 0.11 0.00012 C 0.00023 IRIS 4/10/1998 0.015 Annual REL Cal 12/1/20083 Benzene 71-43-2 216 0.243 C 0.45 IRIS 1/9/2000 30 Annual RfC IRIS 4/17/20034 Bromoform 75-25-2 437 0.49 C 0.91 IRIS 1/1/1991 70 Annual RfD IRIS 3/1/19915 1,3-Butadiene 106-99-0 14.4 0.016 C 0.03 IRIS 11/5/2002 2 Annual RfC IRIS 11/5/20021Cadmium and cadmium compounds6 7440-43-9 0.27 0.0003 C 0.00056 IRIS 6/1/1992 0.02 Annual REL Cal 1/1/20017 Carbon tetrachloride 56-23-5 81.6 0.092 C 0.17 IRIS 3/31/2010 0.1 Annual RfC IRIS 3/31/20108 Chloroform 67-66-3 20.6 0.023 C 0.043 IRIS 10/19/2001 300 Annual REL Cal 4/1/2000N,IA9 Chloroprene [2-Chloro-1,3-butadiene] 126-99-8 0.96 0.0011 C 0.002 MI 11/22/2000 0.02 Annual RfC IRIS 9/30/2010 hexavalent 110 Chromium & Cr compounds 7440-47-3 0.040 0.000045 C 0.000083 IRIS 9/3/1998 0.008 Annual RfC IRIS 9/3/1998 trivalent 1Chromium & Cr compounds 16065-83-1 110 0.10 0.10 NC 5 8hr ITSL Mich 12/26/1995N,IA11 1,4-Dichlorobenzene 106-46-7 43.7 0.049 C 0.091 CA 4/1/1999 800 Annual RfC IRIS 11/1/1996IA12 Ethyl acrylate 140-88-5 33.6 0.038 C 0.07 MI 2/8/1984 30 24hr ITSL Mich13 Formaldehyde 50-00-0 37.0 0.042 C 0.077 IRIS 5/1/1991 9 ...