| Cas - Cg | Nummer |
| Cäsium | 2 / 12 |
| Cäsium-fluorid | 5 |
| Cäsium-hydroxid | 2 / 12 |
| Cäsium-nitrat | 12 |
| Cassia angustifolia | 16 / 18 |
| Cassiaöl | 16 |
| Cassia senna | |
| Cassinsäure | 16 / 13 |
| Catalpa bignonioides | xxx |
| (+)-Catechin | 14a |
| Catechusäure | |
| Catha edulis | 16 |
| Catharanthus roseus | 14 / 3 |
| Cathin | 14 |
| Cathinon | |
| Caulerpenyn | |
| Caulophyllum thalictroides | 16 |
| Cedernholzöl | 10 / gelegentlich 18 |
| Cedron | 16 |
| Cefodizim-Dinatrium | 14 |
| exo-Cellobio-hydrolase | 16 / 18 |
| Cellulase(n) | |
| Cellulose | 16 |
| Cellulose-nitrat | xxx |
| Centaurea cyanus | 18 |
| Centella asiatica | |
| Cephaelin | 14 |
| Cephaëlis ipecacuanha | 14 / 18 |
| Cephalosporin C Zinksalz | 18 |
| Cer-(IV)-ammonium-nitrat | 16 / 13 / # 6 Augen |
| Cerberigenin | 14 |
| Cerberosid | |
| Ceresrot G | 16 |
| Ceriumoxid-iso-stearat | xxx |
| Cerotinsäure | 16 |
| Cetoctaelat | xxx |
| Cetyl-aminhydro-fluorid | 16 |
| Cetyl-palmitat | |
| N-Cetyl-pyridinium-bromid | 14 |
| 1-Cetyl-pyridinium-chlorid Monohydrat | |
| Cetyl-säure | 16 |
| N-Cetyl-N,N,N-tri-methyl-ammonium-bromid |