Substance

Ethidium bromide

(Dromilac, homidium bromide)

CAS 1239-45-8

Formula

C₂₁H₂₀BrN₃

Physical Properties

Dark red crystals

mp 260 to 262 °C

Soluble in water (5 g/100 mL)

Odor

Odorless solid

Major Hazards

Potent mutagen

Toxicity

Acute toxic effects from exposure to ethidium bromide have not been thoroughly investigated. Ethidium bromide is irritating to the eyes, skin, mucous membranes, and upper respiratory tract.

Although there is no evidence for the carcinogenicity or teratogenicity of this substance in humans, ethidium bromide is strongly mutagenic and therefore should be regarded as a possible carcinogen and reproductive toxin.

Flammability and Explosibility

Ethidium bromide does not pose a flammability hazard (NFPA rating = 1).

Reactivity and Incompatibility

No incompatibilities are known.

Storage and Handling

Ethidium bromide should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C. Because of its mutagenicity, stock solutions of this compound should be prepared in a fume hood, and protective gloves should be worn at all times while handling this substance. Operations capable of generating ethidium bromide dust or aerosols of ethidium bromide solutions should be conducted in a fume hood to prevent exposure by inhalation.

Accidents

In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If ethidium bromide is ingested, obtain medical attention immediately.

In the event of a spill, mix ethidium bromide with an absorbent material (avoid raising dust), place in an appropriate container, and dispose of properly. Soak up aqueous solutions with a spill pillow or absorbent material.