Substance profile
Iodine
Iodine is bluish-black scales or plates; diatomic; violet vapor with a sharp characteristic odor.
01 · Identification
What Iodine is
Iodine is bluish-black scales or plates; diatomic; violet vapor with a sharp characteristic odor. It boils at 184 °C, melts at 114 °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 |
|---|---|
| H332 | Harmful if inhaled. |
| H312 | Harmful in contact with skin. |
| H400 | Very toxic to aquatic life. |
Precautionary statements: P260, P271, P273, P280, P302, P304, P312, P352, P391, P501
03 · Physical and chemical properties
Iodine 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 | 184.4 °C (363.9 °F) | HSDB | |
| 185 °C (365 °F) | NIOSH | ||
| 185 °C (365 °F) | at 760 mmHg | CAMEO | |
| Melting point | 113.7 °C (236.7 °F) | HSDB | |
| 113.33 °C (236 °F) | NIOSH | ||
| Density | 4.93 g/cm³ | NIOSH | |
| 0.0113 g/cm³ | at 20 °C | HSDB | |
| Solubility | Dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide to form purple solns. | HSDB | |
| 2.719 g in cyclohexane; 23 g/100 cc in methanol at 25 °C; 20.5 g/100 cc in alcohol at 15 °C; 20.6 g/100 cc in ether at 17 °C | at 25 °C | HSDB | |
| Vapor pressure | 0.233 mmHg | at 25 °C | HSDB |
| 0.3 mmHg | at 25 °C | NIOSH | |
| Lower explosive limit (LEL) | Noncombustible Solid | NIOSH | |
| Vapor density | 8.8 (air = 1) | ICSC | |
| 6.75 g/L at 101.3 MPa, 185 °C | at 185 °C, at 759813 mmHg | HSDB | |
| Odor threshold | Odor low= 9.00 mg/cu m; Odor high= 9.00 mg/cu m; Irritating Concn= 2.0 mg/cu m | HSDB | |
| Critical temperature and pressure | 546 °C (1014.8 °F) | HSDB | |
| Corrosivity | Vapor is corrosive | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Iodine
Storage conditions
Materials which are toxic as stored or which can decompose into toxic components ... Should be stored in a cool, well-ventilated place, out of the direct rays of the sun, away from areas of high fire hazard, and should be periodically inspected. Incompatible materials should be isolated ... .
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
The reaction between liquid chlorine and iodine is violent.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
IODINE is an oxidizing agent. Reacts vigorously with reducing materials. Incompatible with powdered metals in the presence of water (ignites), with gaseous or aqueous ammonia (forms explosive products), with acetylene (reacts explosively), with acetaldehyde (violent reaction), with metal azides (forms yellow explosive iodoazides), with metal hydrides (ignites), with metal carbides (ignites easily), with potassium and sodium (forms shock-senstive explosive compounds) and with alkali-earth metals (ignites). Incompatible with ethanol, formamide, chlorine, bromine, bromine trifluoride, chlorine trifluoride.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Iodine in the storage compatibility matrix →