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Priority List of Hazardous Substances

The Priority List of Hazardous Substances
That Will Be the Subject of Toxicological Profiles


What is the Substance Priority List (SPL)?


The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) section 104 (i), as amended by the Superfund Amendments and Reauthorization Act (SARA), requires ATSDR and the EPA to prepare a list, in order of priority, of substances that are most commonly found at facilities on the National Priorities List (NPL) and which are determined to pose the most significant potential threat to human health due to their known or suspected toxicity and potential for human exposure at these NPL sites. CERCLA also requires this list to be revised periodically to reflect additional information on hazardous substances.

This substance priority list is revised and published on a 2-year basis, with a yearly informal review and revision. (No list was published in 2009 while ATSDR transitioned to a new agency science database.) Each substance on the list is a candidate to become the subject of a toxicological profile prepared by ATSDR. The listing algorithm prioritizes substances based on frequency of occurrence at NPL sites, toxicity, and potential for human exposure to the substances found at NPL sites.

It should be noted that this priority list is not a list of "most toxic" substances, but rather a prioritization of substances based on a combination of their frequency, toxicity, and potential for human exposure at NPL sites.

Thus, it is possible for substances with low toxicity but high NPL frequency of occurrence and exposure to be on this priority list. The objective of this priority list is to rank substances across all NPL hazardous waste sites to provide guidance in selecting which substances will be the subject of toxicological profiles prepared by ATSDR.

Where can I find more information on the Substance Priority List?


There is a Support Document to the Priority List of Hazardous Substances that describes in detail how the list is developed. There is also a Detailed Data Table showing the breakdown of the total scores for each substance on the priority list. These documents and other supporting information are available on the Substance Priority List Resource Page.

The ATSDR 2013 Substance Priority List

2013
RANK
SUBSTANCE NAME TOTAL
POINTS
2011
RANK
CAS RN
1 ARSENIC 1670.4 1 007440-38-2
2 LEAD 1529.2 2 007439-92-1
3 MERCURY 1458.6 3 007439-97-6
4 VINYL CHLORIDE 1359.8 4 000075-01-4
5 POLYCHLORINATED BIPHENYLS 1343.5 5 001336-36-3
6 BENZENE 1328.5 6 000071-43-2
7 CADMIUM 1318.7 7 007440-43-9
8 BENZO(A)PYRENE 1304.7 8 000050-32-8
9 POLYCYCLIC AROMATIC HYDROCARBONS 1279.7 9 130498-29-2
10 BENZO(B)FLUORANTHENE 1251.2 10 000205-99-2
11 CHLOROFORM 1203.5 11 000067-66-3
12 AROCLOR 1260 1190.3 12 011096-82-5
13 DDT, P,P'- 1181.5 13 000050-29-3
14 AROCLOR 1254 1171.2 14 011097-69-1
15 DIBENZO(A,H)ANTHRACENE 1155.4 15 000053-70-3
16 TRICHLOROETHYLENE 1151.4 16 000079-01-6
17 CHROMIUM, HEXAVALENT 1146.9 17 018540-29-9
18 DIELDRIN 1142.5 18 000060-57-1
19 PHOSPHORUS, WHITE 1141.4 19 007723-14-0
20 HEXACHLOROBUTADIENE 1128.2 20 000087-68-3
21 DDE, P,P'- 1126.2 21 000072-55-9
22 CHLORDANE 1125.9 22 000057-74-9
23 COAL TAR CREOSOTE 1124.5 23 008001-58-9
24 AROCLOR 1242 1124.3 24 053469-21-9
25 ALDRIN 1114.6 25 000309-00-2
26 DDD, P,P'- 1113.3 26 000072-54-8
27 AROCLOR 1248 1103.8 27 012672-29-6
28 HEPTACHLOR 1100.7 28 000076-44-8
29 AROCLOR 1099.4 29 012767-79-2
30 BENZIDINE 1090.5 30 000092-87-5
31 ACROLEIN 1088.4 31 000107-02-8
32 TOXAPHENE 1087.4 32 008001-35-2
33 TETRACHLOROETHYLENE 1075.7 33 000127-18-4
34 YHEXACHLOROCYCLOHEXANE, GAMMA- 1074.9 34 000058-89-9
35 CYANIDE 1070.2 35 000057-12-5
36 HEXACHLOROCYCLOHEXANE, BETA- 1053.5 36 000319-85-7
37 DISULFOTON 1047.1 38 000298-04-4
38 BENZO(A)ANTHRACENE 1046.0 37 000056-55-3
39 1,2-DIBROMOETHANE 1041.7 39 000106-93-4
40 ENDRIN 1037.7 40 000072-20-8
41 DIAZINON 1036.6 41 000333-41-5
42 HEXACHLOROCYCLOHEXANE, DELTA- 1034.8 42 000319-86-8
43 BERYLLIUM 1031.0 43 007440-41-7
44 ENDOSULFAN 1027.7 44 000115-29-7
45 AROCLOR 1221 1027.0 45 011104-28-2
46 1,2-DIBROMO-3-CHLOROPROPANE 1025.7 46 000096-12-8
47 HEPTACHLOR EPOXIDE 1020.9 47 001024-57-3
48 ENDOSULFAN, ALPHA 1018.0 48 000959-98-8
49 CIS-CHLORDANE 1015.6 49 005103-71-9
50 CARBON TETRACHLORIDE 1012.6 50 000056-23-5
51 COBALT 1011.7 52 007440-48-4
52 AROCLOR 1016 1011.5 51 012674-11-2
53 DDT, O,P'- 1007.8 54 000789-02-6
54 PENTACHLOROPHENOL 1007.6 53 000087-86-5
55 METHOXYCHLOR 1005.9 55 000072-43-5
56 ENDOSULFAN SULFATE 1003.4 56 001031-07-8
57 NICKEL 996.2 57 007440-02-0
58 DI-N-BUTYL PHTHALATE 994.9 58 000084-74-2
59 ENDRIN KETONE 991.6 59 053494-70-5
60 DIBROMOCHLOROPROPANE 982.9 60 067708-83-2
61 BENZO(K)FLUORANTHENE 971.3 61 000207-08-9
62 TRANS-CHLORDANE 967.8 63 005103-74-2
63 ENDOSULFAN, BETA 967.2 64 033213-65-9
64 XYLENES, TOTAL 965.3 62 001330-20-7
65 CHLORPYRIFOS 963.8 65 002921-88-2
66 CHROMIUM(VI) TRIOXIDE 960.0 66 001333-82-0
67 AROCLOR 1232 957.9 67 011141-16-5
68 ENDRIN ALDEHYDE 957.4 68 007421-93-4
69 METHANE 952.8 69 000074-82-8
70 3,3'-DICHLOROBENZIDINE 940.4 72 000091-94-1
71 2-HEXANONE 940.3 70 000591-78-6
72 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN 939.9 71 001746-01-6
73 BENZOFLUORANTHENE 935.6 73 056832-73-6
74 TOLUENE 918.8 74 000108-88-3
75 ZINC 915.5 75 007440-66-6
76 PENTACHLOROBENZENE 906.8 77 000608-93-5
77 DI(2-ETHYLHEXYL)PHTHALATE 905.2 76 000117-81-7
78 CHROMIUM 896.4 78 007440-47-3
79 AROCLOR 1240 888.3 79 071328-89-7
80 NAPHTHALENE 878.0 80 000091-20-3
81 2,4,6-TRINITROTOLUENE 877.3 82 000118-96-7
82 1,1-DICHLOROETHENE 876.6 81 000075-35-4
83 BROMODICHLOROETHANE 866.2 85 000683-53-4
84 2,4,6-TRICHLOROPHENOL 866.0 83 000088-06-2
85 BIS(2-CHLOROETHYL) ETHER 865.9 84 000111-44-4
86 DDD, O,P'- 865.6 87 000053-19-0
87 HYDRAZINE 860.8 88 000302-01-2
88 METHYLENE CHLORIDE 860.8 86 000075-09-2
89 2,4-DINITROPHENOL 858.1 89 000051-28-5
90 4,4'-METHYLENEBIS(2-CHLOROANILINE) 857.3 90 000101-14-4
91 1,2-DICHLOROETHANE 853.3 91 000107-06-2
92 THIOCYANATE 845.8 92 000302-04-5
93 HEXACHLOROBENZENE 843.6 93 000118-74-1
94 ASBESTOS 840.9 94 001332-21-4
95 RADIUM-226 832.9 95 013982-63-3
96 RDX (Cyclonite) 831.9 96 000121-82-4
97 URANIUM 831.4 97 007440-61-1
98 2,4-DINITROTOLUENE 830.8 98 000121-14-2
99 ETHION 829.9 99 000563-12-2
100 RADIUM 827.3 100 007440-14-4
101 4,6-DINITRO-O-CRESOL 827.0 101 000534-52-1
102 THORIUM 824.0 102 007440-29-1
103 DIMETHYLARSINIC ACID 821.1 103 000075-60-5
104 CHLORINE 820.3 104 007782-50-5
105 1,3,5-TRINITROBENZENE 818.5 106 000099-35-4
106 RADON 818.4 105 010043-92-2
107 HEXACHLOROCYCLOHEXANE, ALPHA- 816.7 107 000319-84-6
108 RADIUM-228 815.1 108 015262-20-1
109 THORIUM-230 813.6 109 014269-63-7
110 URANIUM-235 812.0 111 015117-96-1
111 THORIUM-228 810.2 113 014274-82-9
112 URANIUM-234 809.5 112 013966-29-5
113 RADON-222 809.2 114 014859-67-7
114 1,1,1-TRICHLOROETHANE 808.4 110 000071-55-6
115 COAL TARS 808.1 115 008007-45-2
116 METHYLMERCURY 807.2 120 022967-92-6
117 N-NITROSODI-N-PROPYLAMINE 807.2 118 000621-64-7
118 COPPER 806.9 125 007440-50-8
119 CHRYSOTILE ASBESTOS 806.1 119 012001-29-5
120 PLUTONIUM-239 805.9 120 015117-48-3
121 POLONIUM-210 805.5 122 013981-52-7
122 PLUTONIUM-238 805.2 123 013981-16-3
123 LEAD-210 805.1 124 014255-04-0
124 CHLOROBENZENE 804.3 117 000108-90-7
125 AMOSITE ASBESTOS 804.2 127 012172-73-5
125 PLUTONIUM 804.2 127 007440-07-5
125 STRONTIUM-90 804.2 127 010098-97-2
128 RADON-220 804.2 130 022481-48-7
129 AMERICIUM-241 803.8 131 086954-36-1
130 ETHYLBENZENE 803.5 116 000100-41-4
131 BARIUM 802.8 126 007440-39-3
132 AZINPHOS-METHYL 802.5 134 000086-50-0
133 CHLORDECONE 802.1 135 000143-50-0
134 NEPTUNIUM-237 801.9 136 013994-20-2
135 HYDROGEN CYANIDE 801.6 137 000074-90-8
136 PLUTONIUM-240 801.4 138 014119-33-6
137 1,2,3-Trichlorobenzene 800.1 139 000087-61-6
138 FLUORANTHENE 800.0 133 000206-44-0
139 MANGANESE 798.8 140 007439-96-5
140 S,S,S-TRIBUTYL PHOSPHOROTRITHIOATE 797.5 141 000078-48-8
141 CHRYSENE 791.8 142 000218-01-9
142 2,4,5-TRICHLOROPHENOL 790.2 143 000095-95-4
143 POLYBROMINATED BIPHENYLS 784.2 144 067774-32-7
144 DICOFOL 783.7 145 000115-32-2
145 SELENIUM 776.4 146 007782-49-2
146 1,1,2,2-TETRACHLOROETHANE 775.8 147 000079-34-5
147 HEPTACHLORODIBENZO-P-DIOXIN 773.4 148 037871-00-4
148 PARATHION 773.3 149 000056-38-2
149 HEXACHLOROCYCLOHEXANE, TECHNICAL GRADE 772.9 150 000608-73-1
150 TRICHLOROFLUOROETHANE 772.3 151 027154-33-2
151 BROMINE 770.0 152 007726-95-6
152 AROCLOR 1268 763.8 New 011100-14-4
153 1,3-BUTADIENE 760.9 155 000106-99-0
154 HEPTACHLORODIBENZOFURAN 755.2 153 038998-75-3
155 TRIFLURALIN 754.2 154 001582-09-8
156 1,2,3,4,6,7,8,9-OCTACHLORODIBENZOFURAN 742.6 156 039001-02-0
157 AMMONIA 741.2 157 007664-41-7
158 2-METHYLNAPHTHALENE 726.8 158 000091-57-6
159 1,4-DICHLOROBENZENE 723.4 159 000106-46-7
160 2,3,4,7,8-PENTACHLORODIBENZOFURAN 723.4 161 057117-31-4
161 1,1-DICHLOROETHANE 722.5 160 000075-34-3
162 NALED 720.4 162 000300-76-5
163 1,1,2-TRICHLOROETHANE 719.5 165 000079-00-5
164 HEXACHLOROCYCLOPENTADIENE 717.9 163 000077-47-4
165 1,2-DIPHENYLHYDRAZINE 717.6 164 000122-66-7
166 PHORATE 715.0 166 000298-02-2
167 TRICHLOROETHANE 712.3 167 025323-89-1
168 ACENAPHTHENE 710.2 168 000083-32-9
169 TETRACHLOROBIPHENYL 709.1 169 026914-33-0
170 OXYCHLORDANE 705.4 170 027304-13-8
171 PALLADIUM 705.3 171 007440-05-3
172 CRESOL, PARA- 703.2 172 000106-44-5
173 GAMMA-CHLORDENE 701.9 174 056641-38-4
174 INDENO(1,2,3-CD)PYRENE 701.8 173 000193-39-5
175 TETRACHLOROPHENOL 696.9 176 025167-83-3
176 1,2-DICHLOROBENZENE 696.6 175 000095-50-1
177 1,2-DICHLOROETHENE, TRANS- 692.3 177 000156-60-5
178 CHLOROETHANE 687.2 178 000075-00-3
179 ALUMINUM 686.6 181 007429-90-5
180 PHENOL 686.1 179 000108-95-2
181 P-XYLENE 685.9 180 000106-42-3
182 CARBON MONOXIDE 682.2 183 000630-08-0
183 CARBON DISULFIDE 681.8 182 000075-15-0
184 2,4-DIMETHYLPHENOL 679.2 184 000105-67-9
185 DIBENZOFURAN 675.8 185 000132-64-9
186 ACETONE 673.1 186 000067-64-1
187 HEXACHLOROETHANE 669.2 187 000067-72-1
188 Butyl methyl phthalate 667.3 188 034006-76-3
189 CHLOROMETHANE 665.0 189 000074-87-3
190 HEXACHLORODIBENZOFURAN 659.7 190 055684-94-1
191 BUTYL BENZYL PHTHALATE 657.6 191 000085-68-7
192 HYDROGEN SULFIDE 656.2 192 007783-06-4
193 DICHLORVOS 655.3 193 000062-73-7
194 DIBENZOFURANS, CHLORINATED 652.8 195 042934-53-2
195 CRESOL, ORTHO- 652.4 194 000095-48-7
196 HEXACHLORODIBENZO-P-DIOXIN 651.3 196 034465-46-8
197 VANADIUM 649.8 197 007440-62-2
198 N-NITROSODIMETHYLAMINE 648.2 198 000062-75-9
199 1,2,4-TRICHLOROBENZENE 646.4 199 000120-82-1
200 ETHOPROP 643.5 200 013194-48-4
201 TETRACHLORODIBENZO-P-DIOXIN 641.0 201 041903-57-5
202 BROMOFORM 634.3 202 000075-25-2
203 PENTACHLORODIBENZOFURAN 631.3 203 030402-15-4
204 1,3-DICHLOROBENZENE 627.7 204 000541-73-1
205 PENTACHLORODIBENZO-P-DIOXIN 625.4 205 036088-22-9
206 N-NITROSODIPHENYLAMINE 624.7 206 000086-30-6
207 2,3,7,8-TETRACHLORODIBENZOFURAN 618.7 207 051207-31-9
208 2,4-DICHLOROPHENOL 618.0 208 000120-83-2
209 2,3-DIMETHYLNAPHTHALENE 617.5 209 000581-40-8
210 1,4-DIOXANE 614.8 210 000123-91-1
211 FLUORINE 613.2 211 007782-41-4
212 CESIUM-137 609.9 214 010045-97-3
212 Chromic Acid 609.9 214 007738-94-5
214 NITRITE 608.9 216 014797-65-0
215 2-BUTANONE 608.3 212 000078-93-3
216 1,2-DICHLOROETHYLENE 608.0 213 000540-59-0
217 POTASSIUM-40 607.5 218 013966-00-2
218 DINITROTOLUENE 607.2 219 025321-14-6
219 SILVER 605.4 217 007440-22-4
220 COAL TAR PITCH 605.2 221 065996-93-2
221 NITRATE 605.1 220 014797-55-8
222 THORIUM-227 604.9 222 015623-47-9
223 ARSENIC ACID 604.3 223 007778-39-4
224 FORMALDEHYDE 604.2 241 000050-00-0
225 ARSENIC TRIOXIDE 603.8 224 001327-53-3
226 BENZOPYRENE 603.4 225 073467-76-2
227 CHLORDANE, TECHNICAL 602.5 226 012789-03-6
228 STROBANE 602.5 227 008001-50-1
229 4-AMINOBIPHENYL 602.4 228 000092-67-1
229 PYRETHRUM 602.4 228 008003-34-7
231 ARSINE 602.4 230 007784-42-1
231 DIMETHOATE 602.4 230 000060-51-5
233 CARBOPHENOTHION 601.9 233 000786-19-6
234 ALPHA-CHLORDENE 601.4 234 056534-02-2
234 IODINE-131 601.4 234 010043-66-0
234 MERCURIC CHLORIDE 601.4 234 007487-94-7
234 SODIUM ARSENITE 601.4 234 007784-46-5
234 URANIUM-233 601.4 234 013968-55-3
239 ANTIMONY 600.7 232 007440-36-0
240 DIBROMOCHLOROMETHANE 599.5 239 000124-48-1
241 CRESOLS 596.7 240 001319-77-3
242 DICHLOROBENZENE 594.9 242 025321-22-6
243 2,4-D ACID 594.3 243 000094-75-7
244 2-CHLOROPHENOL 590.6 244 000095-57-8
245 BUTYLATE 589.8 245 002008-41-5
246 PHENANTHRENE 585.2 246 000085-01-8
247 DIMETHYL FORMAMIDE 585.2 247 000068-12-2
248 4-NITROPHENOL 579.4 248 000100-02-7
249 DIURON 578.7 249 000330-54-1
250 TETRACHLOROETHANE 576.4 250 025322-20-7
251 DICHLOROETHANE 567.4 251 001300-21-6
252 ETHYL ETHER 564.9 252 000060-29-7
253 DIMETHYLANILINE 561.7 254 000121-69-7
254 PYRENE 561.3 253 000129-00-0
255 1,3-DICHLOROPROPENE, CIS- 560.5 255 010061-01-5
256 1,2,3,4,6,7,8-HEPTACHLORODIBENZO-P-DIOXIN 558.6 256 035822-46-9
257 PHOSPHINE 555.2 257 007803-51-2
258 TRICHLOROBENZENE 554.9 258 012002-48-1
259 2,6-DINITROTOLUENE 554.0 259 000606-20-2
260 FLUORIDE ION 549.0 260 016984-48-8
261 1,2,3,4,6,7,8-HEPTACHLORODIBENZOFURAN 548.5 261 067562-39-4
262 PENTAERYTHRITOL TETRANITRATE 548.1 262 000078-11-5
263 1,3-DICHLOROPROPENE, TRANS- 547.6 263 010061-02-6
264 ACRYLONITRILE 543.0 264 000107-13-1
265 BIS(2-ETHYLHEXYL)ADIPATE 542.2 265 000103-23-1
266 CARBAZOLE 538.7 266 000086-74-8
267 METOLACHLOR 538.1 267 051218-45-2
268 2-CHLOROANILINE 537.9 268 000095-51-2
269 1,2,3-TRICHLOROPROPANE 535.9 269 000096-18-4
270 CARBARYL 535.4 270 000063-25-2
271 1,2-DICHLOROETHENE, CIS- 534.5 271 000156-59-2
272 STYRENE 528.1 273 000100-42-5
273 METHYL ISOBUTYL KETONE 527.6 272 000108-10-1
274 THALLIUM 524.7 274 007440-28-0
275 1,2,3,7,8,9-HEXACHLORODIBENZOFURAN 524.0 275 072918-21-9

Substances were assigned the same rank when two (or more) substances received equivalent total point scores.

CAS #= Chemical Abstracts Service Registry Number

 

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