The following is a list of U.S. National Classification Codes (U.S. NPC) that CAS has used in its patent selection process since January 2003.
This list contains the U.S. NPC codes that are covered by CAS, i.e., patent documents that have one or more of these NPC codes are automatically selected for examination by the CAS document analysts. The selected patent documents are abstracted and indexed by CAS if they meet the CAS criteria of chemical and chemical engineering content.
The following is a list of U.S. National Classification Codes (U.S. NPC) that CAS has used in its patent selection process since January 2003.
This list contains the U.S. NPC codes that are covered by CAS, i.e., patent documents that have one or more of these NPC codes are automatically selected for examination by the CAS document analysts. The selected patent documents are abstracted and indexed by CAS if they meet the CAS criteria of chemical and chemical engineering content.
| Class | Class Title |
|---|---|
| 8 | BLEACHING AND DYEING; FLUID TREATMENT AND CHEMICAL MODIFICATION OF TEXTILES AND FIBERS |
| 23 | CHEMISTRY: PHYSICAL PROCESSES |
| 44 | FUEL AND RELATED COMPOSITIONS |
| 48 | GAS: HEATING AND ILLUMINATING |
| 51 | ABRASIVE TOOL MAKING PROCESS, MATERIAL, OR COMPOSITION |
| 55 | GAS SEPARATION |
| 65 | GLASS MANUFACTURING |
| 71 | CHEMISTRY: FERTILIZERS |
| 75 | SPECIALIZED METALLURGICAL PROCESSES, COMPOSITIONS FOR USE THEREIN,CONSOLIDATED METAL POWDER COMPOSITIONS, AND LOOSE METAL PARTICULATE MIXTURES |
| 95 | GAS SEPARATION: PROCESSES |
| 96 | GAS SEPARATION: APPARATUS |
| 106 | COMPOSITIONS: COATING OR PLASTIC |
| 117 | SINGLE-CRYSTAL, ORIENTED-CRYSTAL, AND EPITAXY GROWTH PROCESSES; NON-COATING APPARATUS THEREFOR |
| 118 | COATING APPARATUS |
| 127 | SUGAR, STARCH, AND CARBOHYDRATES |
| 134 | CLEANING AND LIQUID CONTACT WITH SOLIDS |
| 136 | BATTERIES: THERMOELECTRIC AND PHOTOELECTRIC |
| 148 | METAL TREATMENT |
| 149 | EXPLOSIVE AND THERMIC COMPOSITIONS OR CHARGES |
| 156 | ADHESIVE BONDING AND MISCELLANEOUS CHEMICAL MANUFACTURE |
| 159 | CONCENTRATING EVAPORATORS |
| 162 | PAPER MAKING AND FIBER LIBERATION |
| 196 | MINERAL OILS: APPARATUS |
| 201 | DISTILLATION: PROCESSES, THERMOLYTIC |
| 202 | DISTILLATION: APPARATUS |
| 203 | DISTILLATION: PROCESSES, SEPARATORY |
| 204 | CHEMISTRY: ELECTRICAL AND WAVE ENERGY |
| 205 | ELECTROLYSIS: PROCESSES, COMPOSITIONS USED THEREIN, AND METHODS OF PREPARING THE COMPOSITIONS |
| 208 | MINERAL OILS: PROCESSES AND PRODUCTS |
| 210 | LIQUID PURIFICATION OR SEPARATION |
| 216 | ETCHING A SUBSTRATE: PROCESSES |
| 252 | COMPOSITIONS |
| 260 | CHEMISTRY OF CARBON COMPOUNDS |
| 261 | GAS AND LIQUID CONTACT APPARATUS |
| 264 | PLASTIC AND NONMETALLIC ARTICLE SHAPING OR TREATING: PROCESSES |
| 266 | METALLURGICAL APPARATUS |
| 347 | INCREMENTAL PRINTING OF SYMBOLIC INFORMATION |
| 376 | INDUCED NUCLEAR REACTIONS: PROCESSES, SYSTEMS, AND ELEMENTS |
| 419 | POWDER METALLURGY PROCESSES |
| 420 | ALLOYS OR METALLIC COMPOSITIONS |
| 422 | CHEMICAL APPARATUS AND PROCESS DISINFECTING, DEODORIZING, PRESERVING,OR STERILIZING |
| 423 | CHEMISTRY OF INORGANIC COMPOUNDS |
| 424 | DRUG, BIO-AFFECTING AND BODY TREATING COMPOSITIONS |
| 426 | FOOD OR EDIBLE MATERIAL: PROCESSES, COMPOSITIONS, AND PRODUCTS |
| 427 | COATING PROCESSES |
| 428 | STOCK MATERIAL OR MISCELLANEOUS ARTICLES |
| 429 | CHEMISTRY: ELECTRICAL CURRENT PRODUCING APPARATUS, PRODUCT,AND PROCESS |
| 430 | RADIATION IMAGERY CHEMISTRY: PROCESS, COMPOSITION, OR PRODUCT THEREOF |
| 435 | CHEMISTRY: MOLECULAR BIOLOGY AND MICROBIOLOGY |
| 436 | CHEMISTRY: ANALYTICAL AND IMMUNOLOGICAL TESTING |
| 438 | SEMICONDUCTOR DEVICE MANUFACTURING: PROCESS |
| 442 | FABRIC (WOVEN, KNITTED, OR NONWOVEN TEXTILE OR CLOTH, ETC.) |
| 501 | COMPOSITIONS: CERAMIC |
| 502 | CATALYST, SOLID SORBENT, OR SUPPORT THEREFOR: PRODUCT OR |
| 503 | RECORD RECEIVER HAVING PLURAL INTERACTIVE LEAVES OR A COLORLESS COLOR FORMER, METHOD OF USE, OR DEVELOPER THEREFOR |
| 504 | PLANT PROTECTING AND REGULATING COMPOSITIONS |
| 505 | SUPERCONDUCTOR TECHNOLOGY: APPARATUS, MATERIAL, PROCESS |
| 507 | EARTH BORING, WELL TREATING, AND OIL FIELD CHEMISTRY |
| 508 | SOLID ANTI-FRICTION DEVICES, MATERIALS THEREFOR, LUBRICANT OR SEPARATE COMPOSITIONS FOR MOVING SOLID SURFACES, AND MISCELLANEOUS MINERAL OIL COMPOSITIONS |
| 510 | CLEANING COMPOSITIONS FOR SOLID SURFACES, AUXILIARY COMPOSITIONS THEREFOR, OR PROCESSES OF PREPARING THE COMPOSITIONS |
| 512 | PERFUME COMPOSITIONS |
| 514 | DRUG, BIO-AFFECTING AND BODY TREATING COMPOSITIONS |
| 516 | COLLOID SYSTEMS AND WETTING AGENTS; SUBCOMBINATIONS THEREOF; PROCESSES OF |
| 518 | CHEMISTRY: FISCHER-TROPSCH PROCESSES; OR PURIFICATION OR RECOVERY OF PRODUCTS THEREOF |
| 520 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 521 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 522 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 523 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 524 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 525 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 526 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 527 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 528 | SYNTHETIC RESINS OR NATURAL RUBBERS |
| 530 | CHEMISTRY: NATURAL RESINS OR DERIVATIVES; PEPTIDES OR PROTEINS;LIGINS OR REACTION PRODUCTS THEREOF |
| 532 | ORGANIC COMPOUNDS |
| 534 | ORGANIC COMPOUNDS |
| 536 | ORGANIC COMPOUNDS |
| 540 | ORGANIC COMPOUNDS |
| 544 | ORGANIC COMPOUNDS |
| 546 | ORGANIC COMPOUNDS |
| 548 | ORGANIC COMPOUNDS |
| 549 | ORGANIC COMPOUNDS |
| 552 | ORGANIC COMPOUNDS |
| 554 | ORGANIC COMPOUNDS |
| 556 | ORGANIC COMPOUNDS |
| 558 | ORGANIC COMPOUNDS |
| 560 | ORGANIC COMPOUNDS |
| 562 | ORGANIC COMPOUNDS |
| 564 | ORGANIC COMPOUNDS |
| 568 | ORGANIC COMPOUNDS |
| 570 | ORGANIC COMPOUNDS |
| 585 | CHEMISTRY OF HYDROCARBON COMPOUNDS |
| 588 | HAZARDOUS OR TOXIC WASTE DESTRUCTION OR CONTAINMENT |
| 800 | MULTICELLULAR LIVING ORGANISMS AND UNMODIFIED PARTS THEREOF AND RELATED PROCESSES |
| 930 | PEPTIDE OR PROTEIN SEQUENCE |
| 935 | GENETIC ENGINEERING: RECOMBINANT DNA TECHNOLOGY, HYBRID OR FUSED CELL TECHNOLOGY, AND RELATED MANIPULATIONS OF NUCLEIC ACIDS |
| 976 | NUCLEAR TECHNOLOGY |
| PLT | PLANTS |