State Tightens Rules on Termite Fumigation

Under emergency rules imposed by the state Environmental Protection Agency, California homeowners will pay more to have their houses fumigated for termites and will have to stay out longer after the treatment to avoid potentially harmful levels of toxic gas.

The new rules were imposed last month, after two studies showed that both types of gas used in California’s 150,000 annual fumigations for drywood termites remain in structures longer than previously believed.

Two other studies showed that the fumigant used most often in Southern California, methyl bromide, caused birth defects in animals exposed to high doses of the chemical. State officials said there is no evidence that methyl bromide causes birth defects in humans, but the length of time houses are aired out after fumigation is being extended as a precaution.

The emergency regulations were imposed following the deaths of two Redwood City residents after their apartment house was fumigated with methyl bromide. But Cal EPA spokeswoman Veda Federighi said the new rules were not prompted by the deaths. The state had been working on the new regulations for several months before the victims died, she said.

The Jan. 17 death of Gary Barthold was attributed methyl bromide intoxication. The March 31 death of Kathy Monahan, Barthold’s roommate, is still under investigation. Officials are also studying whether proper procedures were used by the fumigation company.

It has been more than a dozen years since a death occurred after a building had been cleared for re-entry. Several other deaths occurred when people deliberately entered houses while they were being fumigated. Those victims were either burglars or people who were drunk or trying to commit suicide, according to state officials.

In Southern California, most fumigations are done when a home is sold, because mortgage lenders require a report showing that any termites in a house have been eradicated, said John Munro, administrative assistant at the Pest Control Operators of California, an industry trade group. Home sellers typically want to save money and use the cheaper methyl bromide treatment, he said.

But many pest control operators are now switching to the more expensive fumigant, Vikane (sulfuryl fluoride), because it has a shorter waiting period after fumigation before occupants can re-enter a building.

Under the new regulations--which are temporary until additional tests are completed--fumigations with Vikane will require residents to stay out of the house for one or two days, while four days are usually needed for methyl bromide fumigations. The length of time depends on whether fans are used to help ventilate the house, and results of air tests to determine how much gas, if any, remains.

Previously, people usually only had to leave the house for about 24 hours.

Orkin spokeswoman Judith Donner said staying out of the house for the extra 72 hours is “a really big inconvenience to customers,” so the Atlanta-based company has stopped using methyl bromide.

Consumers will pay about 25% more for a fumigation because of the higher cost of Vikane, as well as the extra labor required to make additional visits to check the house, said Lee Blevins, president of Antimite , a Rancho Cucamonga-based pest control company.

A fumigation for a one-story house with 2,000 square feet of living space and a detached garage would have cost about $900 before the changes, Blevins said. The new price is about $1,120, he said.

Besides longer aeration periods, the state’s new interim regulations also require that lower levels of methyl bromide be reached before a building is cleared for re-entry. The level previously considered safe was five parts per million. But one study found levels rise after residents enter a home and close windows and doors.

Levels tend to rise as gas continues to seep out of furniture and walls, particularly areas with little air circulation.

The levels for methyl bromide have now been lowered to three parts per million, and fumigators must test air inside the walls, where gas levels may be higher than inside the room.

Rudolf Scheffrahn, a University of Florida associate professor who did one of the studies, said while levels of both fumigants can rise sharply, they don’t remain high for very long.

He said that in the worst-case scenario, where a person immediately re-enters the house after it is cleared for re-entry and closes all windows and doors, the levels peaked within 90 minutes of closing up the house, then dropped.

However, concerns about a different study, which found birth defects in animals exposed to high levels of methyl bromide, led officials to decide on a longer waiting period, said Federighi, who is with Cal EPA’s department of pesticide regulation.

The required longer aeration and lower levels of gas provide an extra margin of safety, she said. The state didn’t want to ban methyl bromide entirely because it costs less to use than Vikane. Research data indicates that Vikane does not cause birth defects.

The new rules also mandate that consumers be given a four-page fact sheet, which explains the fumigation process, describes symptoms of possible poisoning, and lists telephone numbers to call for more information. Any symptoms generally show up within a day or two after exposure, Federighi said.

The state expects to issue permanent regulations within several weeks. The U.S. EPA plans to adopt similar regulations and is asking manufacturers to voluntarily comply with the new directions until permanent changes go into effect within a few weeks.

The extra safety measures are not enough for several environmental groups, who want to see methyl bromide banned entirely.

“I’m not sure that any level of methyl bromide is going to be safe,” said Susan Cooper, staff ecologist for the National Coalition Against the Misuse of Pesticides.

Less toxic alternatives are available, said Sharon Taylor, pesticide reduction director for the Environmental Health Coalition in San Diego.

The longer aeration periods could lead more consumers to try alternatives to fumigation, including treatments that freeze or heat termite-inhabited spaces.

Jay Tallon, chief executive officer of Tallon Termite & Pest Control, said his company has received some calls from consumers seeking alternatives to the new fumigation rules. Tallon uses both freezing and heating methods.

Many traditional pest control operators say they are waiting to see more research that alternative methods can kill all termites in a house before adopting the new methods.

Statewide, methyl bromide is used in about half the fumigations and Vikane in the other half, according to the PCOC.

Another chemical, chloropicrin, is added to both fumigants to warn people of the presence of the odorless gases. Chloropicrin has a strong odor and irritates the eyes.

But methyl bromide has been used in as many as 75% of Southern California fumigations, mainly because it is cheaper, said Blevins, the pest control operator.

Northern California’s climate causes different termite problems and fumigations are done for other reasons besides home sales, Munro said, so methyl bromide is used less often in that region.

The choice of fumigant may also depend on other factors besides cost.

Methyl bromide is more effective against other types of pests, including powderpost beetles, but can react with rubber, furs and other substances to form a permanent odor.

Drywood termites are the most common type found in Southern California homes, according to the PCOC. Another type of termite, the subterranean variety, is treated by applying a different type of chemical into the soil. Some houses have both kinds of termites and need both a fumigation and soil treatment.

About 26% of the 28.1 million pounds of methyl bromide used in California during 1990 was used for structural fumigation; the rest was used to fumigate agricultural fields and commodities.

The state Department of Pesticide Regulation also plans studies on possible risks to agricultural workers from methyl bromide, to determine whether more protective measures are needed.

Besides possible health risks from fumigation, environmentalists would like to see the commercial use of methyl bromide banned immediately because they believe it depletes the earth’s ozone layer. Thinning of the protective ozone layer is blamed for increases in skin cancer and cataracts.

Although use of methyl bromide is supposed to be phased out by the year 2000 because of the federal Clean Air Act, environmental groups are concerned its use may be extended.