U.S. National Patent Classifications Used by CAS

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.

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