Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

Build a label

Substance profile

Bromine

Bromine is a dark reddish-brown, volatile, mobile diatomic liquid; vaporizes at room temperature with a suffocating odor.

CAS 7726-95-6 Br2 159.81 g/mol Danger

01 · Identification

What Bromine is

Bromine is a dark reddish-brown, volatile, mobile diatomic liquid; vaporizes at room temperature with a suffocating odor. Its molecular formula is Br2 and its molecular weight is 159.81 g/mol. It boils at 58.8 °C, melts at -7.2 °C.

Under the GHS it carries the signal word Danger. It is classed as corrosives.

CAS number7726-95-6
EC number231-778-1
Index number035-001-00-5
Molecular formulaBr2
Molecular weight159.81 g/mol
Chemical class Corrosives

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.

Signal wordDanger
Hazard statements assigned to Bromine
CodeHazard statement
H330 Fatal if inhaled.
H314 Causes severe skin burns and eye damage.
H400 Very toxic to aquatic life.

Precautionary statements: P260, P271, P273, P280, P301, P304, P310, P331, P391, P501

03 · Physical and chemical properties

Bromine 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 58.8 °C (137.8 °F) HSDB
59.44 °C (139 °F) NIOSH
59.56 °C (139.2 °F) at 760 mmHg CAMEO
Melting point -7.2 °C (19 °F) HSDB
-7.22 °C (19 °F) NIOSH
Density 3.12 g/cm³ NIOSH
3.1023 g/cm³ at 25 °C HSDB
Solubility Water solubility: 35.8 g/L at 20 °C; 41.7 g/L at 0 °C at 20 °C HSDB
Solubility in water (25 °C): 0.2141 mol/L with formation of 0.00115 mol/L of HOBr at 25 °C HSDB
In water, 33.6 g/L at 25 °C at 25 °C HSDB
Vapor pressure 172 mmHg NIOSH
172 mmHg at 20.6 °C CAMEO
212 mmHg at 25 °C HSDB
Autoignition temperature Not flammable (USCG, 1999) CAMEO
Lower explosive limit (LEL) Fire and Explosion Hazards: Strong oxidizer. Heat of reaction may ignite combustibles on contact. May accelerate combustion reactions. HSDB
Noncombustible Liquid, but accelerates the burning of combustibles. NIOSH
Vapor density 5.5 (air = 1) ICSC
5.51 (air = 1) OSHA
5.51 (air = 1) at 15 °C CAMEO
Odor threshold ODOR THRESHOLDS OF 0.05-3.5 PPM HAVE BEEN REPORTED. HSDB
Odor low 0.329 mg/cu m; Odor high 24.5 mg/cu m HSDB
Air odor threshold: 0.051 ppm (v/v); water odor threshold: 0.0063 ppm (w/v) HSDB
Critical temperature and pressure 315 °C (599 °F) HSDB
Corrosivity Corrosive material HSDB
Vapor is highly corrosive to many materials and human tissue HSDB
Attacks most metals, including platinum and palladium; dry bromine does not attack lead, nickel, magnesium, tantalum, iron, zinc or (below 300 °C) sodium HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling Bromine

Storage conditions

Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Do not store in polyethylene containers. Handle and open container with care.

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

During bromination of acetone to bromoacetone, presence of a large excess of bromine must be avoided to prevent sudden and violent reaction.

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

BROMINE SOLUTION is an oxidizing agent. Bromine disproportionates rapidly in basic water to give bromide ion and bromate ion. The latter is also an oxidizing agent. Dissolution lowers reactivity compared to pure bromine. Reacts with reducing reagents. Reacts with hydrogen, diethylzinc, dimethylformamide, ammonia, trimethylamine, nitromethane, metal azides (silver or sodium azide). Can react with Mg, Sr, B, Al, Hg, Ti, Sn, Sb in powder or sheet form, to form bromides. Can react with methanol, ethanol, aldehydes, ketones, carboxylic acids, diethyl ether, carbonyl compounds, tetrahydrofuran, acrylonitrile, ozone, phosphorus, natural rubber. Reactions with red phosphorus, metal azides, nitromethane, silane and its homologues may be vigorous.[Bretherick, 5th ed., 1995, p. 109].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Bromine in the storage compatibility matrix →

Get the free GHS / CLP / OSHA deadline calendar

Verified 2026–2029 compliance dates in one PDF — plus alerts when the rules change.