Substance profile
Citric acid
Citric acid is crystals; monoclinic holohedra; crystallizes from hot concentrated aqueous solution and is odorless.
01 · Identification
What Citric acid is
Citric acid is crystals; monoclinic holohedra; crystallizes from hot concentrated aqueous solution and is odorless. Its molecular formula is C6H8O7 and its molecular weight is 192.12 g/mol. It melts at 153 °C.
Under the GHS it carries the signal word Warning.
Other names for Citric acid
- C6H8O7
- Aciletten
- Anhydrous Citric Acid
- Beta-Hydroxy-Tricarboxylic Acid
- Beta-Hydroxytricarballylic Acid
- Chemfill
- Citretten
- Citro
- Hydrocerol A
- 2-Hydroxy-1,2,3-Propane-Tricarboxylic Acid
- 2-Hydroxy-1,2,3-Propanetricarboxylic Acid
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 |
|---|---|
| H335 | May cause respiratory irritation. |
| H319 | Causes serious eye irritation. |
Precautionary statements: P264, P280, P305, P313, P337, P338
03 · Physical and chemical properties
Citric acid 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 | Decomposes | decomposes | HSDB |
| Decomposes (NTP, 1992) | decomposes | CAMEO | |
| Melting point | 153 °C (307.4 °F) | HSDB | |
| 152.78 °C (307 °F) | CAMEO | ||
| Density | 1.542 g/cm³ | Citric acid monohydrate | HSDB |
| 1.665 g/cm³ | at 20 °C | HSDB | |
| 0.9002 g/cm³ | at 25 °C | HSDB | |
| Solubility | Very soluble in ethanol; soluble in ether, ethyl acetate; insoluble in benzene, chloroform | HSDB | |
| greater than or equal to 100 mg/mL at 72 °F (NTP, 1992) | at 22.22 °C | CAMEO | |
| In water, 3.83X10+5 mg/L at 25 °C | at 25 °C | HSDB | |
| Flash point | 100 °C (212 °F) | ICSC | |
| Autoignition temperature | 1010 °C (1850 °F) | HSDB | |
| Lower explosive limit (LEL) | 0.28 % by volume | HSDB | |
| 0.28-2.29 KG/CU M (DUST) | HSDB | ||
| Upper explosive limit (UEL) | 2.29 % by volume | HSDB | |
| 2.29 kg/m3 (dust) (NTP, 1992) | CAMEO | ||
| Corrosivity | WILL CORRODE COPPER, ZINC, ALUMINUM AND THEIR ALLOYS | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Citric acid
Storage conditions
Crystalline citric acid, anhydrous, can be stored in dry form without difficulty, although conditions of high humidity and elevated temperatures should be avoided to prevent caking. Storage should be in tight containers to prevent exposure to moist air. Several granulations are commercially available with the larger particle sizes having less tendency toward caking.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Potentially explosive reaction with metal nitrates.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
CITRIC ACID reacts with oxidizing agents, bases, reducing agents and metal nitrates (NTP, 1992). Reactions with metal nitrates are potentially explosive. Heating to the point of decomposition causes emission of acrid smoke and fumes [Lewis].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Citric acid in the storage compatibility matrix →
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