Substance profile
Caffeine
Caffeine is white, prismatic crystals and is odorless.
01 · Identification
What Caffeine is
Caffeine is white, prismatic crystals and is odorless. Its molecular formula is C8H10N4O2 and its molecular weight is 194.19 g/mol. It boils at 178 °C, melts at 236 °C.
Under the GHS it carries the signal word Warning.
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
03 · Physical and chemical properties
Caffeine properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 178 °C (352.4 °F) | sublimes, sublimes | HSDB |
| 177.78 °C (352 °F) | sublimes, at 760 mmHg | CAMEO | |
| Melting point | 236.2 °C (457.2 °F) | HSDB | |
| 237.78 °C (460 °F) | CAMEO | ||
| 235 °C (455 °F) | ICSC | ||
| Density | 1.23 g/cm³ | ICSC | |
| 1.23 g/cm³ | at 18 °C | HSDB | |
| 1.23 g/cm³ | at 17.78 °C | CAMEO | |
| Solubility | Solubility in water is increased by alkali benzoates, cinnamates, citrates or salicylates | HSDB | |
| Soluble in pyridine | HSDB | ||
| In water, 2.16X10+4 mg/L at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 9e-7 mmHg | at 25 °C | HSDB |
| 1e-8 mmHg | Haz-Map | ||
| Odor threshold | Aroma threshold values: Detection at 29 to 300 ppm | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Caffeine
Storage conditions
Separated from food and feedstuffs. Well closed.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
CAFFEINE may be hygroscopic. Aqueous solutions (1.12 mg/mL) are stable for three weeks at 41 °F if protected from light. In normal room lighting and at room temperature, solutions are stable for 3 days. Solutions of this chemical in water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal lab conditions. REACTIVITY: This compound may react with strong oxidizing agents. It is also incompatible with iodine, silver salts and tannins. This compound is a very weak base. It is decomposed by strong solutions of caustic alkalis. (NTP, 1992)
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Caffeine in the storage compatibility matrix →