As homeowners embrace more efficient lighting technologies, remodelers, electricians, and other contractors should think twice before tossing light bulbs and lighting fixtures in the trash.

Growing in popularity due to their long life and low energy usage, compact fluorescent (CFL) and other energy-efficient light bulbs such as linear fluorescent and high-intensity discharge (HID) lamps contain a very small amount of mercury, a poisonous substance. Ten states and multiple local jurisdictions prohibit the disposal of mercury-containing products--including CFLs and other mercury-containing bulbs--in solid waste. (For state-by-state regulations click here.)

Just as pros learned to safely dispose of old mercury thermostats, they will need to devise a plan for the way they dispose of remodeling waste containing these new types of bulbs, says Mark Kohorst, senior manager for environment, health, and safety for the National Electrical Manufacturers Association (NEMA).

“For example, in the past a contractor doing a kitchen remodeling project would gut the kitchen and didn’t worry about the old fixtures and bulbs—for the most part 25-cent incandescents—that were going in the trash,” says Kohorst. “As the marketplace changes, some of this lighting could now include CFLs, which need to be treated as special waste.”

But even with the threat of fines and penalties, the residential building industry has been slow to embrace CFL recycling, says Mark Tibbetts, director of NEMA’s recycling initiative.

“Recyclers find contractors to be a very tough market to crack, partly because there hasn’t been a real threat of enforcement,” Tibbetts says. “But as a contractor, you are liable if these lamps are part of your demolition.”

In coming years, pros are sure to find more of these types of bulbs in the houses they remodel, Tibbetts adds. CFL use is expected to grow in part because traditional incandescent bulbs will be phased out by 2014 under the federal Clean Energy Act. In many areas, energy companies already are offering incentives such as mail-in rebates to incite homeowners to switch to CFLs.

“The residential contracting community is going to start seeing a lot more of these in people’s homes,” says Tibbetts.

Although pricier than an incandescent, a high-quality CFL bulb can save about $30 over its lifetime and pays for itself in about six months. It uses 75% less energy and lasts about 10 times longer than an incandescent bulb.

The Home Depot, IKEA, and other hardware chains offer free in-store CFL recycling, and utility-run collection programs exist in Maine, Vermont, Wisconsin, Illinois, Washington, Oregon, Florida, California, and Minnesota. To find a recycler, click here.

Kohorst likened the push to raise awareness for CFL recycling among consumers and contractors to that of the government’s 1978 announcement banning lead-based paints and products in American homes. “It just required the contractor community to be aware of something additional in terms of what they do and in how they operate their businesses,” he says.

Jennifer Goodman is Senior Editor Online for EcoHome.