CFLs, or Compact Fluorescent Light bulbs, have been touted as the eco-breakthrough of the century. We’ve all been told to make the switch now, to reduce energy use and to prevent greenhouse emissions which contribute to global warming.

All of this hype is true, but before you change over completely, read on, because there is a dark side to CFLs.

Incandescent bulbs use more electricity than CFLs. This is true. However, when they break, we can vacuum them up, throw the residue in the trash, screw in another one and never think about it again.

A broken CFL is different. Before you go hog-wild over these “great” new light bulbs, you owe it to yourself, your family and future generations to learn the truth because soon, most of the incandescent bulbs we are accustomed to will either be illegal or just not available.

CFLs contain mercury. Mercury is the component that allows the efficiency of the light source. The fact that CFLs contain mercury, however, is a problem. Mercury is poisonous. Although they contain a small amount, it could be an environmental concern in the future for landfills, groundwater near those landfills, the air we breathe if that mercury becomes airborne, and water pollution from leaching out of soils. None of these problems will occur overnight, but as with most environmental disasters, the consequences appear over time.

Warning: Contains mercury. Handle with care.

A more pressing, immediate issue with CFLs was brought to my attention by the U.S. Environmental Protection Agency. This government agency has published guidelines on how to clean up after a CFL light bulb is broken in your home.

CFLs must be double-bagged in plastic bags, and labeled as hazardous waste. The EPA even describes the complicated ways the mercury is to be secured and picked up. Squeegies and sulfur dust (which is also poisonous) are suggested.

Many cities are purchasing machines to crush these bulbs under negative-pressure ventilation with a mercury-absorbing filter or cold trap which treats contaminated gases. Imagine having to treat every burned-out light bulb with such care to protect the environment and your family’s health! Do you really think the EPA and the people who oversee these things will go to these lengths to protect you?

The EPA advises that if you have a CFL break in your house, do the following (from the EPA website):

1. Open a window and leave the room for 15 minutes or more.

2. Carefully scoop up the fragments and powder with stiff paper or cardboard and place them in a sealed plastic bag.

* Use disposable rubber gloves, if available (i.e., do not use bare hands). Wipe the area clean with damp paper towels or disposable wet wipes and place them in the plastic bag.

* Do not use a vacuum or broom to clean up the broken bulb on hard surfaces.

3. Place all cleanup materials in a second sealed plastic bag.

* Place the first bag in a second sealed plastic bag and put it in the outdoor trash container or in another outdoor protected area for the next normal trash disposal.

Note: Some states prohibit such trash disposal and require that broken and unbroken lamps be taken to a local recycling center.

* Wash your hands after disposing of the bag.

* (Another site suggests taking this plastic bag to a hazardous waste facility.)

4. If a fluorescent bulb breaks on a rug or carpet:

* First, remove all materials you can without using a vacuum cleaner, following the steps above. Sticky tape (such as duct tape) can be used to pick up small pieces and powder.

* If vacuuming is needed after all visible materials are removed, vacuum the area where the bulb was broken, remove the vacuum bag (or empty and wipe the canister) and put the bag or vacuum debris in two sealed plastic bags in the outdoor trash or protected outdoor location for normal disposal. (Or take it to a hazardous waste facility.)

A thing of nostalgia.

The EPA also advises the poor consumer what he should never do (also from the EPA website):

* Never use a vacuum cleaner to clean up mercury. The vacuum will put mercury into the air and increase exposure. The vacuum appliance will be contaminated and have to be thrown away.

* Never use a broom to clean up mercury. It will break the mercury into smaller droplets and spread them.

* Never pour mercury down a drain. It may lodge in the plumbing and cause future problems during plumbing repairs. If discharged, it can cause pollution of the septic tank or sewage treatment plant.

* Never wash mercury-contaminated items in a washing machine. Mercury may contaminate the machine and/or pollute sewage.

* Never walk around if your shoes might be contaminated with mercury. Contaminated clothing can also spread mercury around.

The EPA is continually updating its recommendations on CFL cleanup. If more than two tablespoons of mercury are spilled in the home, it becomes a HAZMAT clean up, and too dangerous for the consumer to attempt alone. (Two tablespoons equal about 1 pound of mercury.)

Imagine if you had CFLs in all of your lamps at home and there were an earthquake. Every room could be contaminated with mercury.

Now that I have shown you the dark side, you can make an informed decision. Contribute to global warming, or contribute to pollution in your home if the bulb breaks? There are definite advantages to using these bulbs, and if they are cared for with great caution, disposed of properly, and if lamps are secured to the wall to prevent breakage, and if you never have a broken bulb, we all win. The bulb’s in your court.

Dianne Erskine-Hellrigel is executive director of the Community Hiking Club and president of the Santa Clara River Watershed Conservancy.