Table A2.
Critical Element forms listed on the 2019 Agency for Toxic. Substances and Disease Registry Substance Priority List a.
| Ranking | Substance Name | CAS b |
|---|---|---|
| 1 | Arsenic | 7440-38-2 |
| 14 | Chromium (VI) hexavalent | 18540-29-9 |
| 43 | Beryllium | 7440-41-7 |
| 58 | Chromium (VI) trioxide | 1333-82-0 |
| 70 | Cobalt | 7440-48-4 |
| 94 | Nickel | 7440-02-0 |
| 136 | Barium | 7440-39-3 |
| 150 | Chromium | 7440-47-3 |
| 155 | Fluorine | 7782-41-4 |
| 164 | Zinc | 7440-66-6 |
| 173 | Palladiumc | 7440-05-3 |
| 188 | Manganese | 7439-96-5 |
| 228 | Cesium-137 | 10045-97-3 |
| 244 | Antimony | 7440-36-0 |
| 277 | Vanadium | 7440-62-2 |
| 281 | Aluminum | 7429-90-5 |
| 351 | Titanium | 7440-32-6 |
| 359 | Lithium | 7439-93-2 |
| 360 | Chromium, trivalent | 16065-83-1 |
| 362 | Tin | 7440-31-5 |
| 376 | Cesium-134 | 13967-70-9 |
| 384 | Tungsten | 7440-33-7 |
| 448 | Indiumc | 7440-74-6 |
| 470 | Cerium | 7440-45-1 |
| 476 | Neodymium | 7440-00-8 |
| 479 | Germaniumc | 7440-56-4 |
| 492 | Bismuth-214 | 14733-03-0 |
| 494 | Bismuth-212 | 14913-49-6 |
| 510 | Ytterbium | 7440-64-4 |
| 511 | Scandium | 7440-20-2 |
| 513 | Gallium | 7440-55-3 |
| 514 | Niobium | 7440-03-1 |
| 519 | Tellurium | 13494-80-9 |
| 525 | Cobalt-60 | 10198-40-0 |
| 545 | Chromium (IV) | 15723-28-1 |
| 550 | Europium | 7440-53-1 |
| 551 | Dysprosium | 7429-91-6 |
| 551 | Praseodymium | 7440-10-0 |
| 551 | Samarium | 7440-19-9 |
| 566 | Aluminum oxide | 1344-28-1 |
| 578 | Cesium | 7440-46-2 |
| 578 | Lanthanum | 7439-91-0 |
| 578 | Magnesium | 7439-95-4 |
| 578 | Rubidium | 7440-17-7 |
| 578 | Yttrium | 7440-65-5 |
| 578 | Zirconium | 7440-67-7 |
| 692 | Tantalum c | 7440-25-7 |
a The list includes substances determined to be of greatest public health concerns to persons at or near national priority list sites. (https://www.atsdr.cdc.gov/spl/index.html#2019spl; accessed on 30 May 22). b Chemical Abstracts Service registry number. c Included on version 1 of the 2019 list.