What precautions should be taken when using ethidium bromide

Ethidium bromide’s ability to bind with DNA makes it highly mutagenic. Exposure can occur through inhalation, ingestion and skin absorption. Avoiding any of these routes of exposure requires several precautions to be taken at every step from storage and handling to disposal.

Storage precautions:

• EtBr must be stored in a cool dark place away from potent oxidizing agents.
• Keep the container tightly closed when not in use to avoid accidental spills and limit exposure.

Handling precautions:

• Avoid using powdered EtBr as it generates dust that can spread and contaminate surrounding surfaces, increasing the risk of exposure.
• Use dedicated equipment and a fume hood to minimize exposure through inhalation or direct contact.
• Wear appropriate personal protective equipment including UV-blocking eyewear, long sleeved clothing, a lab coat and nitrile gloves. Wearing double nitrile rubber gloves is recommended when working with high concentrations for extended periods of time.
• Always wash hands thoroughly after taking off your personal protective clothing and gloves.
• Avoid microwaving EtBr in any form as this can generate toxic vapors that can be easily inhaled.
• After clean-up, check for residual EtBr contamination using a hand-held UV lamp.

Disposal precautions:

• Place solid contaminated items such as equipment used, gloves, agarose gels and paper towels in double-bagged, sealed, plastic containers and request a toxic waste removal.
• Liquid waste can be disposed of the same way as solid waste or it can be deactivated and poured down the drain along with copious amounts of water.