| Abbreviation | Meaning | Category |
| C | Chemisches Zentralblatt (auch: Central-blatt) | Periodika |
| c | Konzentration einer optisch aktiven Verbindung in g/100 ml Lösung | Andere |
| C. r | Comptes rendus des séances de l'académie des sciences | Periodika |
| c.c. | closed cup (geschlossenes Gefäss) | Andere |
| C.I. | Color Index | Andere |
| c/o | care of | Andere |
| CA | Canada | Andere |
| CA | Chemical Abstracts | Andere |
| ca. | circa | Andere |
| CAFC | Court of Appeals for the Federal Circuit (USA) | Andere |
| calcd. | calculated | Andere |
| CAS | Chemical Abstracts Service-Nr. | Andere |
| cat. | catalyst, catalyzed | Andere |
| CBD | Convention on Biological Diversity | Andere |
| CCP | Certificat complementaire du Protection (earlier FR version of SPC) | Andere |
| CDA | Confidential Disclosure Agreement | Andere |
| CEIPI | Centre d’Etudes Internationales de la Propriété Industrielle | Andere |
| cf. | compare | Andere |
| CFI | Court of First Instance (EU) | Andere |
| CFR | Code of Federal Regulations (United States) | Andere |
| cfu | colony forming units | Andere |
| CH | Switzerland | Andere |
| Ch. I | Chemische Industrie | Periodika |
| Ch. Z | Chemiker Zeitung | Periodika |
| Chap. | chapter | Andere |
| Chem. N | Chemical News | Periodika |
| ChemG | Chemikaliengesetz | Andere |
| Chlf | Chloroform | Substanz |
| CIOS | Combined Intelligence Objectives Subcommitee Report (see also FIAT) | Andere |
| cip | Continuation in part (USA) | Andere |
| CLICAPS | Chemistry Library Information Control And Presentation System | Andere |
| CNS | central nervous system | Andere |
| Co. | Company | Andere |
| COD | chemical oxygen demand | Andere |
| conc. | concentrated | Andere |
| const. | constant | Andere |
| Corp. | Corporation | Andere |
| CP | Community Patent (EU) | Andere |
| CPA | Chartered Patent Agent/Attorney | Andere |
| CPC | Community Patent Convention | Andere |
| CPL | Chemical Physics Letters | Periodika |
| crit. | critical | Andere |
| CS | Czechoslovakia | Andere |
| CTFA | The Cosmeti, Toiletry and Fragrance Association (United States) | Andere |
| Czech. P. | Czechoslovakian Patent | Andere |
