| Acronym | Meaning |
| ICNIRS | International Council For Near Infrared Spectroscopy |
| ICNZ | International Committee On Natural Zeolites |
| ICOH | International Commission On Occupational Health |
| ICOLC | International Coalition Of Library Consortia |
| ICOLP | Industry Cooperative For Ozone Layer Protection |
| ICOM | International Congress On Membranes |
| ICON | International Council On Nanotechnology |
| ICOS | Interactive Computer Optimization Of HPLC Sepns. |
| ICOS | Inducible Co-stimulator |
| ICP | Inductively Coupled Plasma |
| ICP | Interactive Correlation Partitioning |
| ICP-AES | Inductively Coupled Plasma-atomic Emission Spectrometry |
| ICP-MS | Inductively Coupled Plasma Mass Spectrometry |
| ICP-OES | Inductively Coupled Plasma-optical Emission Spectroscopy |
| ICP-ROA | Incident Circular Polarization Raman Optical Activity |
| ICP/MS | Inductively Coupled Plasma Mass Spectrometry |
| ICPAC | International Committee On Polycyclic Aromatic Compounds |
| ICPAEMC | International Commission For Protection Against Environmental Mutagens And Carcinogens |
| ICPAES | Inductively Coupled Plasma Atomic Emission Spectrometry |
| ICPD | Inductively Coupled Plasma Deposition |
| ICPEMC | International Commission On Protection Against Environmental Mutagens And Carcinogens |
| ICPIC | International Cleaner Production Information Clearinghouse |
| ICPMS | Inductively Coupled Plasma Mass Spectrometry |
| ICPP | Idaho Chemical Processing Plant |
| ICR | Ion Cyclotron Resonance (mass Spectrometry) |
| ICR | Information Collection Rule |
| ICR | Intelligent Optical Character Recognition |
| ICR | Intensified Controlled Rolling |
| ICRF | Imperial Cancer Research Fund |
| ICRF | Ion Cyclotron Range Of Frequencies |
| ICRH | Ion Cyclotron Resonance Heating |
| ICRMS | International Chemical Regulatory Monitoring System |
| ICRMS | Ion Cyclotron Resonance Mass Spectrometry |
| ICRP | International Commission On Radiological Protection |
| ICRU | International Commission On Radiation Units And Measurements |
| ICS | Inhaled Corticosteroid |
| ICS | Intermittant Control Strategy |
| ICSC | International Chemical Safety Card |
| ICSCF | Internally Consistent Self-consistent Field |
| ICSD | Inorganic Crystal Structure Database |
| ICSH | Interstitial Cell-stimulating Hormone |
| ICSI | Intracytoplasmic Sperm Injection |
| ICSS | Intracranial Self-stimulation |
| ICSS | Isobaric Crystallization From Supercritical Solution |
| ICSTI | International Center For Scientific And Technical Information (Moscow |
| ICSU | International Council Of Scientific Unions |
| ICT | Intramol. Charge Transfer |
| ICTA | International Confederation Of Thermal Analysis |
| ICTAC | International Confederation For Thermal Analysis And Calorimetry |
| ICTP | Telopeptide Of Type-I Collagen |