No Tenting Tonight.

Alternative Treatments to Control Termites

If there's wood in your house, chances are at some point you'll have unwelcome houseguests: termites. Treatments to get rid of these trespassers can be environmentally nasty. Infestations in which the entire house is implicated are usually attacked with chemical fumigants. But concerns about ozone depletion and health risks associated with these chemicals have created a growing market for alternative treatments that still spell R.I.P. for the bugs.

Two basic types of termites may be cohabiting with you: drywood and subterranean. Drywood termites are more common in warm, dry climates and live in attics, garages and walls. They may start out infesting the fence surrounding your property, the woodpile out back or even the utility pole across the street. Subterranean termites tunnel in moist soil to find wood, putting decks and lower levels of buildings at risk.

Giving 'em Gas

These days, a house under attack from drywood termites may be chemically fumigated through a process known as tenting. A nylon tarp is draped around the entire building and a poisonous gas--usually Vikane (sulfuryl fluoride)--is pumped inside. Twelve to 24 hours later, the tarp is removed, and the home is aerated for at least six hours.

Consumers often opt for fumigation because of its ability to completely rid a structure of termites. Vikane gas is odorless, colorless and dissipates quickly, leaving no residue. But Vikane is extremely toxic and can depress the central nervous system. Long-term exposure can cause blood and bone problems.

Methyl bromide, which is still sometimes used as a termiticide, aerates more slowly and is an ozone depleter. The Environmental Protection Agency is phasing it out by 2005 in order to comply with Clean Air Act regulations.

Dr. Marion Moses, public health and environmental medicine specialist and founder of the Pesticide Education Center in San Francisco, says methyl bromide, which is still used widely in agriculture, has been linked to serious health problems among those who work around it, including migrant farm workers.

Dow AgroSciences, a manufacturer of Vikane, now offers an alternative method of killing subterranean termites called the Sentricon Colony Elimination System. In this process, worker termites are baited by compact monitoring stations to pick up a tiny amount of poison, which then spreads throughout the colony. The system uses only a fraction of an ounce of termite-specific chemical, and it is environmentally low impact compared with traditional spraying methods. Here are some developing fumigation alternatives for treating drywood termites:

* Heat them. Heating an entire structure or selected area to 120 degrees Fahrenheit will destroy termites and their eggs. The heat will also disinfect the area by eliminating most bacteria, odors and fungi. State-of-the-art digital thermometers and needle-thin probes ensure the wood core temperature is hot enough to kill the insects.

* Freeze them. Pumping liquid nitrogen through tiny holes drilled into infested wood will also eliminate termites. The -350-degree nitrogen is pumped in slowly to gradually lower the wood temperature to -20 Fahrenheit. Tallon Termite and Pest Control in Redondo Beach, California has been using the Blizzard System to freeze termites since 1988. CEO Jay Tallon says it's 100-percent effective. Technicians use fiber optics to pinpoint exactly where the termites are living within the wood.

* Microwave them. Microwave treatments involve a machine that looks like an oven without the door and essentially "cooks" the termites. It is used to treat unexposed areas, like walls or a stucco column. When treating an entire house, microwaving is usually part of the bigger pest-control solution.

* Shock theme. The electrogun is a hand-held device with a 90,000-volt electric current that penetrates wood to electrocute termites. Because the current is pulsating, it doesn't burn the wood.

* Oil them. Oil made from orange peels can kill termites on contact. The oil is injected into wood timbers or, if wood is unpainted, applied topically to soak in. Not only is it effective, but it smells good too.

CONTACT: Pesticide Education Center, [phone], [e-mail]; Ecola Services (electrogun and microwave treatments), www.ecolater mite.com; Tallon Termite and Pest Control (freezing, orange oil, heating and microwave treatments), [phone], www.tallontermite.com.

EILENE ZIMMERMAN is a regular contributor to FSB.com, an online service of Fortune magazine.