Ethidium Bromide
What is Ethidium Bromide?
Ethidium Bromide (3,8 diamino-5-ethyl-6-phenyl phenanthridinium bromide, dromilac), CAS #1239-45-8, is a DNA and RNA polymerase inhibitor used in several of Harvard's laboratories. It is known to be toxic and mutagenic and may be fatal if swallowed, inhaled, or absorbed though the skin. Lesser exposures may cause coughing or sneezing, and irritation of the skin and of the mucous membranes of the eyes and respiratory system.
How Can I Minimize Exposure To Ethidium Bromide?
Several steps can be taken to minimize exposure to ethidium bromide:
- Before working with a chemical, know all of the potential hazards and safety precautions (including what to do in the event of a spill);
- Wear a lab coat, rubber gloves, and goggles;
- Confine all work with ethidium bromide powders to a properly functioning, uncluttered chemical fume hood -- be sure the hood sash is at the correct height (14"). Chambers or enclosed weighing stations can reduce the effects of turbulence on the performance of scales. Also, consider using pre-mixed solutions or pre-measured quantities. It is recommended that you work in a fume hood or with local ventilation when working with stock solutions;
- As with all hazardous substances, work on a disposable mat in the hood, and dispose of used mat properly after work is done (see information below on management/disposal of waste).
What Should I Do in the Event of Exposure or Spills?
In the event of exposure and/or spills, take the following steps:
- In case of accidental inhalation, remove to fresh air and get medical attention.
- If swallowed, get medical attention immediately by calling the Harvard Police (Cambridge 5-1212, Longwood 2-1212).
- For skin exposure, remove contaminated clothing and wash skin with plenty of soap and water for at least 15 minutes; get medical attention.
- For eye exposure, wash eyes with plenty of water for at least 15 minutes, lifting upper and lower eyelids occasionally, then get medical attention.
- For spills of ethidium bromide, clean-up spilled material (avoid raising dust) and dispose appropriately (see below for information on management/disposal of waste).
As with all accidents or incidents, report any exposure as soon as possible to your Lab Supervisor. Remember that help at any time and especially at night and on weekends and holidays is available through the Operations Center (495-5560). Additional health and safety information on ethidium bromide and other chemicals can be obtained by referring to your Material Safety Data Sheet (MSDS) file, the MSDS database on the EH&S web-page or by calling your building Safety Officer, Lab Safety Coordinator, or the EH&S Office.
How Should I Manage and Dispose of Ethidium Bromide Waste?
Ethidium bromide is a mutagen that requires special storage, handling, and disposal as waste. Ethidium bromide waste streams typically include:
- Buffer solutions;
- Gels;
- Stock solutions;
- Crystals and powders; and
- Contaminated debris.
As with any waste generated from activities at Harvard, a concerted effort should be made to minimize ethidium bromide waste wherever possible. Examples of pollution prevention and waste minimization methods include:
- Substituting hazardous materials for less or non-hazardous materials;
- Using dilute rather than concentrated solutions;
- Using micro- or semi-micro techniques; and
- Using computer modeling/simulation, films, videotapes or demonstrations rather than individual experiments.
In addition, laboratories should consider the use of commercially available filter cartridges to remove ethidium bromide from buffers and other dilute aqueous solutions (see Resources below for links to possible vendors). For ethidium bromide waste that is generated at Harvard, each waste stream is to be accumulated and managed as described in the table below.
Ethidium Bromide Waste Management
Non-Hazardous Waste Streams |
||
Waste Stream |
Description |
Waste Management Procedure |
Buffer Solutions |
Typically contain very small concentrations of ethidium bromide (less than 0.01% by wt.) |
May be discharged to sinks |
Gels |
Typically contain trace amounts of ethidium bromide (0.3-0.5 μg/ml) |
Agarose gels with trace amounts of ethidium bromide may be disposed of daily in double bag-lined containers (e.g., five-gallon pails). This waste is not considered a hazardous waste. However, the chemical waste vendor will pick up any vendor-supplied pails that are labeled as "Non-Hazardous Ethidium Bromide Gel Waste". Cambridge labs that have mini-mains will have to bring the pails to the mini-mains when full. |
Hazardous Waste Streams |
||
Waste Stream |
Description |
Waste Management Procedure |
Stock Solutions
Crystals and Powders |
Typically contain relatively high concentrations of pure ethidium bromide |
Place empty stock solution bottles or unused stock solution bottles in double ziplock plastic bags. Place absorbents into bag if available. |
Contaminated Debris |
Includes ethidium bromide contaminated debris (e.g., gloves, mats, tips, spill clean-up waste) from spills of Stock Solution, Crystals or Powder |
Collect waste in double bags. |
NOTES:
- Ethidium bromide-contaminated pasteur pipettes and other sharps must be accumulated in sharps containers.
- If ethidium bromide is mixed with chemicals (e.g., solvents) that are required to be managed as hazardous waste, the waste must be managed and disposed as hazardous waste. For information on hazardous waste management and disposal see the EH&S Hazardous Waste Management webpage
- Resources
- EH&S Assistance and Hazardous Waste Disposal: 496-3322 (Cambridge), 432-1720 (Longwood)
- Material Safety Data Sheet (MSDS) Database
- Possible Ethidium Bromide Removal System (Cartridge) Vendor:
NAIAD Technologies, Inc.
2611 SW Third Avenue, Suite 200, Portland, Oregon 97201
(503) 274-4407 Toll Free: 1-888-ByNaiad (296-2423)
Updated 4/26/10
