BROMINE

Bromine
CAS 7726-95-6

Br₂

Dark red-brown liquid
bp 59 °C, mp -7 °C
Slightly soluble in water (3.5 g/100 mL)

Odor can be detected at concentrations as low as 0.05 ppm; exposure to concentrations below 1 ppm causes lacrimation.

5.5 (air = 1.0)

175 mmHg at 20 °C

Noncombustible

LD₅₀ oral (rat) 2600 mg/kg

LC₅₀ inhal (rat) 2700 mg/m ³

PEL (OSHA) 0.1 ppm

TLV-TWA (ACGIH) 0.1 ppm (0.7 mg/m³)

STEL (ACGIH) 0.3 ppm (2 mg/m³)

Highly corrosive to skin and eyes; moderately toxic via inhalation; reacts violently with readily oxidized substances.

Bromine is highly corrosive to the skin, causing irritation and destruction with blister formation. If bromine is not removed from the skin immediately, deep-seated ulcers develop, which heal slowly. Severely painful and destructive eye burns may result from contact with either liquid or concentrated vapors of bromine. Bromine is a moderately toxic substance via inhalation. There are good warning properties for bromine: lacrimation begins at ~1 ppm, and 50 ppm is highly irritating to humans. A short exposure (minutes) to 1000 ppm would likely be fatal for humans. Vapor exposures can cause irritation and damage to the upper and lower respiratory tract (nose, throat, and lungs) to varying degrees depending on the concentration. If exposure is sufficiently high, it will cause pulmonary edema, which could lead to death. Other reported symptoms of overexposure include coughing, tightness of chest, nosebleed, headache, and dizziness, followed after some hours by abdominal pain, diarrhea, and a measles-like rash on the trunk and extremities.

Animal studies on the chronic toxicity of bromine revealed disturbances in the respiratory, nervous, and endocrine systems after exposure to 0.2 ppm for 4 months; similar exposure to 0.02 ppm did not produce any adverse effects.

Bromine alone is a noncombustible substance (NFPA rating = 0).

Bromine reacts violently with easily oxidized substances, including many organic compounds and a number of metals. Explosions have been reported to occur, for example, on addition of bromine to methanol, acetaldehyde, and DMF. Fires and/or explosions may result from the reactions of bromine with hydrogen, acetylene, ammonia, aluminum, mercury, sodium, potassium, and phosphorus.

Bromine should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C. In particular, work with bromine should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and rubber gloves should be worn at all times when handling this corrosive substance. Containers of bromine should be stored at room temperature in a secondary container separately from readily oxidizable substances.

In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. If irritation or burns develop, seek medical attention. In case of eye contact, promptly wash with copious amounts of water and obtain medical attention. If bromine is ingested, give the person large amounts of milk or water to dilute the bromine (do not attempt to induce vomiting) and obtain medical attention immediately. If a significant amount of bromine is inhaled, move the person to fresh air and seek medical attention at once.

Treat small spills of bromine with sodium thiosulfate and an inert absorbent, place in an appropriate container, and dispose of properly. Large spills may require evacuation of the area and cleanup using full protective equipment.

Excess bromine and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines. Special care should be taken not to mix bromine with incompatible waste materials.

The information in this LCSS has been compiled by a committee of the National Research Council from literature sources and Material Safety Data Sheets and is believed to be accurate as of July 1994. This summary is intended for use by trained laboratory personnel in conjunction with the NRC report Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. This LCSS presents a concise summary of safety information that should be adequate for most laboratory uses of the title substance, but in some cases it may be advisable to consult more comprehensive references. This information should not be used as a guide to the nonlaboratory use of this chemical.

Copyright 1995 National Academy of Sciences. All rights reserved.