7.19 Ethidium Bromide7.19 Ethidium Bromide
Mutagenic chemicals, such as ethidium bromide, pose a threat to organic life due to their ability to modify an organism’s genetic material that may be passed along to future generations.
Active ethidium bromide wastes may not be disposed of via the sanitary sewer or municipal trash without first being deactivated. Ethidium bromide wastes that do not fluoresce are considered to be inactive and could be acceptable for drain or trash disposal depending on the chemical constituents of the dye. There are a variety of options for disposal depending on the type of waste.
7.19.1 Dry Ethidium Bromide Wastes, Including Gloves and Papers7.19.1 Dry Ethidium Bromide Wastes, Including Gloves and Papers
- Materials that do not fluoresce under UV light may be disposed of directly in the trash.
- Deactivate the dye, dry the solids, and dispose via normal trash, OR
- Submit for Chemical Waste Collection a blue "Contaminated Waste Label" – identify the materials as “Ethidium Bromide”.
Ethidium Bromide Gels
- Gels that do not fluoresce under UV light may be disposed of directly in the trash.
- Deactivate the dye, dry the gel, and dispose via trash, OR
- Dry and submit to EHS for collection as Contaminated Waste (request blue EHS label through "askEHS").
- Aqueous dye solutions that do not fluoresce under UV light may be disposed of down the drain.
- Deactivate and dispose down the drain.
- Absorb the ethidium bromide waste on filter media (activated carbon) and submit the media to EHS for Contaminated Waste disposal using the blue EHS label through "askEHS". Options for this method include:
- Any ethidium bromide waste that contains a flammable liquid (such as butanol) should be submitted for Hazardous Waste disposal.
- Concentrated Mutagenic Dyes
- Concentrated mutagenic dyes that are unusable may be submitted for Hazardous Waste disposal. This includes mutagenic dyes that are concentrated by absorption onto a filter media.
7.19.2 Deactivation Procedures7.19.2 Deactivation Procedures
Deactivation is managed by breaking the chemical bonds of ethidium bromide. Within a laboratory setting, these bonds can be broken in several ways, including oxidization and UV radiation. Deactivation of ethidium bromide waste materials must be incorporated as a last step in the research protocol. The methods described here oxidize the mutagen to remove the risk.
The following is from Network News, Volume 8 No. 2, September 1994. Network News is a tri-annual publication of the ACS Department of Government Relations and Science Policy's Office of Legislative and Regulatory Programs. Margaret-Ann Armour is a professor in the Department of Chemistry at the University of Alberta.
Begin by wearing the proper personal protective equipment such as a lab coat, safety glasses, and gloves. To convert ethidium bromide (EtBr) to the physiologically inactive product 2-carboxybenzophenone, stir a solution of 34 mg of ethidium bromide in 100 mL of water (at room temperature) with 300 mL of household bleach for 2 hours. When ethidium bromide solutions of this dilute concentration are used, the product solution does not show excess mutagenicity over standards in the Ames test.
You should check the extent of completion of this process with a Ultra-Violet (UV) lamp. EtBr glows bright orange under UV. If you see no orange fluorescence under the correct wavelength of UV in the detoxified material, then it has effectively been degraded.