MERCURY & CFLs - SSCI Environmental

CFL BulbsMercury is dangerous to us and animals.  This naturally occurring element can affect the nervous system of any animal with too much exposure.  Exposure to mercury during digestion is less hazardous to our bodies than inhalation of mercury gas.  People who inhale large amounts of mercury are susceptible to harm because the mercury absorbs in our lungs and begins attacking our nervous system.  Different animals can be extremely sensitive to ingestion of mercury.

As a child of the 1970s, I remember the scramble of a classroom when a mercury thermometer broke in a classroom.  I remember the hype associate with the proper disposal of mercury as an effort to remove mercury contamination in our landfills.  Being a child of the “no mercury” culture, I have a hard time purchasing a Compact Fluorescent Lamp (CFL) bulb labeled “CONTAINS MERCURY”.  Why not buy the cheaper bulb that does not contain a hazard warning?  Why bother with the hassles of proper disposal?

The facts are that CFL bulbs contain a very small amount of mercury.  On average, CFLs contain about four milligrams of mercury sealed within glass tubing.  By comparison, older thermometers contain about 500 milligrams of mercury – an amount equal to the mercury in over 100 CFL bulbs.  Manufacturers of fluorescent lighting products are working to reduce the amount of mercury content in CFL bulbs.  No mercury is released when the bulbs are intact (i.e., not broken) or in use, but CFLs can release mercury vapor when broken.

Other sources of mercury include thermometers, thermostats and old mercury switches.  Mercury is found in many rocks including coal.  When coal is burned at a utility power plant to produce electricity, mercury is released into the environment.  In the U.S., burning coal at power plants results in about half of all mercury emissions from man-made sources.

Small amounts of mercury can be released into the environment when CFL bulbs break, or if they are improperly disposed of.  Despite these emissions, the use of CFL bulbs actually helps reduce total mercury emissions in the U.S. because of their significant energy savings.  Using energy-saving CFL bulbs reduces demand for electricity, which in turn reduces the amount of coal burned by power plants, which reduces emissions of mercury when the coal is burned.

In the event mercury containing items are broken, keep children and pets away; immediately open windows in the exposed area (if possible); wearing gloves and a face mask clean up the area using rags and items that can be thrown away, this will help to prevent cross contamination into other areas of the house/building.  Place items in a concealed container and then discard.  Liquid mercury should be contained in a glass jar or plastic freezer type bag and delivered to a Household Hazardous Waste (HHW) facility for proper disposal.  Do not vacuum mercury containing bulbs or glass.  Additional directions for cleanup of broken CFL bulbs can be found at

What if I have already been exposed to a shattered CFL bulb?  If you believe you have been exposed to a broken CFL bulb, don’t worry.  The amount of mercury contained in a bulb is equal to approximately the same amount of mercury contained in the Food and Drug Administration (FDA) recommended amount of fish per week.  The FDA encourages people, including pregnant women, to eat fish, but recommends that they eat no more than one 6-ounce meal per week of fish such as Albacore tuna, which is relatively high in mercury content.  Albacore tuna is one of the most commonly consumed fish.  If you are concerned about your mercury exposure, you can limit your fish intake over the next couple of weeks.  (Natural Resource Defense Council).

How do I know if a bulb contains mercury?  The follow types of bulbs typically contain mercury:

  • Fluorescent bulbs:
    • Linear, U-tube and circline fluorescent tubes
    • Bug zappers
    • Tanning bulbs
    • Black lights
    • Germicidal bulbs
    • High output bulbs, and
    • Cold-cathode fluorescent bulbs.
  • High intensity discharge bulbs:
    • Metal halide
    • Ceramic metal halide
    • High pressure sodium, and mercury vapor.
  • Mercury short-arc bulbs; and
  • Neon bulbs.

If I choose to us a CFL bulb, how to I prevent breakage?  Do not touch the glass bulb with bare hands. Oils on your hands may make the bulb susceptible to overheating. Wear gloves or use a cloth. Switch off and allow a working CFL bulb to cool before handling.  Handle CFL bulbs carefully to avoid breakage.  If possible, screw/unscrew the bulb by holding the plastic or ceramic base, not the glass tubing.  Gently screw in the bulb until snug.  Do not over-tighten.  Never forcefully twist the glass tubing.  Consider using a drop cloth (e.g., plastic sheet or beach towel) when changing a fluorescent light bulb in case a breakage should occur.  The drop cloth will help prevent mercury contamination of nearby surfaces and can be bundled with the bulb debris for disposal.  You can also purchase CFL bulbs that have a glass or plastic cover over the spiral or folded glass tube.  These types of bulbs look more like incandescent bulbs and may be more durable if dropped.

There are energy efficient bulbs available as alternatives to CFL bulbs.  Other available options include LEDs (super-efficient, with very low energy costs; pricey, although prices are dropping rapidly), and halogens (inexpensive, more efficient than incandescents, but not as efficient as CFLs or LEDs).

How do I property dispose of CFL bulbs?  CFL bulbs should be disposed of a Household Hazardous Waste (HWW) center.  Centers can be located by visiting your local City or County website.

Why should CFL bulbs be properly disposed of at a Hazardous Waste Center?  CFL bulbs should be properly disposed of at a Hazardous Waste Center to reduce the risk of mercury being released into the environment.  Nearly every component of a CFL bulb can be recycled and reused.

For more information, please follow these links:

City of Houston Environmental Service Centers:

Harris County:

Brazoria & Galveston County:

Other Texas Contacts for HWW: