In the greening hierarchy, reuse is at the top of the heap. Purchasing a piece of refurbished equipment extends the life of the product, diverts material from the landfill and reduces the demand for new products that would require a large amount of resources to create. To be sure, the eco-friendly aspects of refurbished equipment aren't the primary draw, or what drives the market. It's the price tag, which can be 20% to 50% lower, depending on the piece of equipment. But you probably didn't know that refurbishers are some of the thriftiest, most environmentally conscious vendors around.

1. Trashed equipment does more harm than you know. Much of today's medical equipment is made of the same materials found in such consumer electronics as personal computers, televisions, DVD players and cell phones. These products contain toxic substances such as lead, fire retardants, oils and beryllium, which is used as a hardening agent for metal.

For example, a GI endoscopy system contains batteries, a computer circuit board, light bulbs and a monitor. Purchasing a refurbished system keeps all of this out of the ground, says Greg Wenthe, marketing director for repair services at Minneapolis-based SterilMed. "You're not putting 100 pounds (of materials) into the landfill," he explains.

It's important not to dump these items into landfills because of the risk of hazardous chemicals leaching into streams, lakes and our water supply. For example, a computer circuit board, which is common in many devices, can contain a handful of toxic substances, especially if it's treated with fire retardants such as polybrominated diphenyl ethers (PBDE) or tetrabromobisphenol A (TBBPA). Portable devices with rechargeable batteries usually have cadmium in them. Monitors and televisions with cathode ray tubes contain about 4 lbs. of lead, while mercury is used in flat-panel monitors, according to the EPA.

Several states and many local jurisdictions require you to properly dispose of your electronic waste. The national Electronics Recycling Infrastructure Clearing-house publishes an updated list of E-waste laws by state (www.ecyclingresource.org).

2. Refurbishing keeps products working. Depend-ing on the product, much of a device can be reused after refurbishing. At Siemens Healthcare, which has refurbishing programs based in Germany and Hoffman Estates, Ill., 68% of the material in C-arms, ultrasound devices and other imaging equipment that is returned to the factory goes back out in the refurbished products. Another 30% of that material is saved for spare parts, while just 2% goes into the trash. Cables, plastic and other consumable items account for most of the trash, says Sabine Duffy, vice president for refurbished systems at Siemens.

When Siemens buys used equipment or takes trade-ins, the devices are sorted by condition. Spare parts are harvested from non-repairable equipment and the same technicians who build new equipment disassemble reusable devices. Broken parts are replaced, covers and metal parts are painted, and computer hardware and software are updated. The equipment then goes through the same testing that new imaging devices do.

Sending the refurbished equipment back out on the market reduces the carbon footprint of the nearly 1,700 devices refurbished each year. "We're saving 20,000 tons of carbon dioxide" in comparison to the environmental impact of creating new devices, says Ms. Duffy. The CO2 savings is the equivalent to the CO2 generated by the electric power consumption of 5,700 households, according to Siemens.

3. Reused components depend on the device. The makeup of each component determines the eco-friendliness of a refurbished product. For example, a rigid endoscope has more reusable material than a flexible endoscope. Because most of the rigid scope is metal, refurbishing techs only have to replace the lens and fiber-optic components. Not much goes into the trash, which makes a refurbished rigid scope very eco-friendly, says Harvey Buxbaum, president of HMB Endoscopy Products, a firm based in Hollywood, Fla., that sells and repairs endoscopes. When refurbishing a flexible endoscope, however, you're replacing nearly everything except for the handle, says Mr. Buxbaum. "There's not much eco-savings."

4. Reuse lessens demand for resources. Medical equipment is often made of metal, plastic, rubber and other materials that require electricity, water, petroleum and other natural resources. All of this has an environmental impact before pieces of equipment ever leave the production line. When a piece of equipment is reused, the overall environmental impact is lessened. "You're not using the resources to make new equipment," says Mr. Wenthe.

5. Refurbishing diverts material to recycling. Not every part and every piece of used equipment is in suitable condition to be refurbished. Some devices are too old and can't be updated or are beaten up beyond repair. Still, what can't be salvaged for spare parts usually ends up in the recycling stream.

For example, very little material removed from used microscopes goes into the trash bin at Prescott's in Monument, Colo. "For us, there's no money in throwing things away," says Mark Redner, president of the company. Scopes beyond repair are disassembled and hauled away by a recycling company that takes the material to the appropriate scrap depots.

For some companies involved in extending the life of equipment and its parts, recycling has become a significant source of income. Troff Medical Services, based in Hendersonville, N.C., sells spare parts for radiology equipment. The company disassembles used equipment that it buys; anything that can't be sold as spare parts is recycled. Employees remove the plastic covering on wires and cables and sort the plastic and metal into piles of extruded aluminum, cast aluminum and copper wire. The leftover steel goes into a bin for a scrap dealer, while the plastics and more valuable metals go to recyclers.

Five years ago, Troff had to pay to have all its excess materials hauled away, says Mike Helms, owner of the company. But thanks to the evolution of the recycling stream, "it's turned into revenue rather than an expense." Recycling also saves more than 200,000 lbs. of metal from going into the landfill each year. Only non-recyclable materials such as fiberglass and some plastics end up in Troff's trash bin. "Most weeks it doesn't even get filled," says Mr. Helms.