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.

Class
Class Title
008

BLEACHING AND DYEING; FLUID TREATMENT AND CHEMICAL MODIFICATION OF TEXTILES AND FIBERS

023
CHEMISTRY: PHYSICAL PROCESSES
044
FUEL AND RELATED COMPOSITIONS
048
GAS: HEATING AND ILLUMINATING
051
ABRASIVE TOOL MAKING PROCESS, MATERIAL, OR COMPOSITION
055
GAS SEPARATION
065
GLASS MANUFACTURING
071
CHEMISTRY: FERTILIZERS
075
SPECIALIZED METALLURGICAL PROCESSES, COMPOSITIONS FOR USE THEREIN,CONSOLIDATED METAL POWDER COMPOSITIONS, AND LOOSE METAL PARTICULATE MIXTURES
095
GAS SEPARATION: PROCESSES
096
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
987
ORGANIC COMPOUNDS CONTAINING A Bi, Sb, As, OR P ATOM OR CONTAINING A METAL ATOM OF THE 6TH TO 8TH GROUP OF THE PERIODIC SYSTEM
PLT
PLANTS

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