| No. | CAS # | Product Names | Molecular Formula |
| 251 | 13106-76-8 | ammonium molybdate(VI) | (NH4)2MoO4 |
| 252 | 1066-97-3 | Ammonium O,O-dimethyl dithiophosphate | C2H10NO2PS2 |
| 253 | 12411-64-2 | Ammonium octamolybdate | |
| 254 | 6009-70-7 | Ammonium oxalate monohydrate | C2H8N2O4.H2O |
| 255 | 7803-65-8 | Ammonium phosphinate | NH4.H2PO2 |
| 256 | 68333-79-9 | Ammonium Polyphosphate | (NH4PO3)n |
| 257 | 12135-76-1 | Ammonium sulfide | (NH4)2S |
| 258 | 7783-20-2 | Ammonium sulphate | （NH4）2.SO4 |
| 259 | 10196-04-0 | ammonium sulphite | (NH4)2SO3·H2O |
| 260 | 13826-83-0 | Ammonium tetrafluoroborate | |
| 261 | 1762-95-4 | Ammonium thiocyanate | NH4CNS |
| 262 | 7783-18-8 | Ammonium thiosulphate | H8N2O3S2 |
| 263 | 11120-25-5 | ammonium wolframate | H8N2O4W |
| 264 | 26447-10-9 | Ammonium xylenesulfonate | C8H13NO3S |
| 265 | 16837-52-8 | Ammothamnine | C15H24N2O2 |
| 266 | 57-43-2 | Amobarbital | C11H18N2O3 |
| 267 | 6398-98-7 | Amodiaquin dihydrochloride dihydrate | C20H22ClN3O.2(HCl).2(H2O) |
| 268 | 86-42-0 | Amodiaquine | C20H22ClN3O |
| 269 | 106614-68-0 | Amorolfine hydrochloride | C21H35NO.HCl |
| 270 | 78613-38-4 | AMOROLFINE HYDROCHLORIDE | C21H36ClNO |
| 271 | 78613-35-1 | Amorolfine | C21H35NO |
| 272 | 14808-60-7 | Amorphous silica | SiO2 |
| 273 | 26787-78-0 | amoxicillin | C16H19N3O5S |
| 274 | 1397-89-3 | Amphotericin B | C47H73NO17 |
| 275 | 69-52-3 | Ampicillin sodium | C16H18N3NaO4S |
| 276 | 69-53-4 | ampicillin | C16H19N3O4S |
| 277 | 7177-48-2 | Ampicillin | C16H19N3O4S.3（H2O） |
| 278 | 99464-64-9 | Ampiroxicam | C20H21N3O7S |
| 279 | 122341-56-4 | AMPPD | C18H23O7P |
| 280 | 137-88-2 | amprolium hydrochloride | C14H19ClN4.HCl |
| 281 | 60719-84-8 | Amrinone | C10H9N3O |
| 282 | 9000-90-2 | Amylase, α- | |
| 283 | 209733-45-9 | Anatibant | C34H36Cl2N6O5S |
| 284 | 12771-68-5 | Ancymidol | C15H16N2O2 |
| 285 | 5508-58-7 | Andrographolide | C20H30O5 |
| 286 | 2243-06-3 | Androst-4-ene-3,6,17-trione | C19H24O3 |
| 287 | 897-06-3 | Androsta-1,4-diene-3,17-dione | C19H24O2 |
| 288 | 63-05-8 | Androstenedione | C19H26O2 |
| 289 | 53-41-8 | Androsterone | C19H30O2 |
| 290 | 223747-83-9 | Angelica dahurica extract | |
| 291 | 000000-00-0 | Angelica extract | |
| 292 | 20071-00-5 | Angiotensin acetate | C49H70N14O11.C2H4O2 |
| 293 | 1407-47-2 | ANGIOTENSIN | C50H71N13O12 |
| 294 | 137-51-9 | Aniline-2,4-disulfonic acid | C6H7NO6S2 |
| 295 | 88-21-1 | Aniline-2-sulfonic acid | C6H7NO3S |
| 296 | 42986-22-1 | Aniline-4-beta-ethyl sulfonyl sulfate-2-sulfonic acid | C8H11O9S3 |
| 297 | 62-53-3 | Aniline | C6H7N |
| 298 | 77855-73-3 | Anilino-methyl-trimethoxysilane | C10H17NO3Si |
| 299 | 64249-01-0 | Anilofos | C13H19ClNO3PS2 |
| 300 | 000000-00-0 | Anion exchange resin |