Arizona, USA — Wildland firefighters are generally encouraged at theprospect of another tool to keep houses tucked in forest settings from burning:a sticky goop, or gel, that holds many times its weight in water.
But they don’t expect to see an immediate rush among Arizona’s municipal firedepartments in the so-called urban-wildland interface to stockpile the stuff.
“I think it’s a valuable product,” said Paul Summerfelt, fieldmanagement officer for the Flagstaff Fire Department. “It’s very effective.There’s no question about its effectiveness.”
The gel is an absorbent polymer capable of retaining moisture for severalhours, and can be sprayed on structures such as homes or cabins from a truck, agarden hose, a backpack or even an airplane.
It will adhere to vertical surfaces and depending on the mix can havea building-sticking consistency almost like petroleum jelly.
Its effectiveness has been shown on houses and structures in forest fires insuch locations as South Dakota’s Black Hills National Forest and Colorado’s MesaVerde National Park and in California.
At least a half-dozen gel products approved after testing by the U.S. ForestService’s Missoula Technology and Development Center in Montana are being soldcommercially.
Since 2002, wildfires have destroyed more than 800 Arizona homes. TheRodeo-Chediski Fire, the largest wildfire in Arizona history, burned 491 homesthat year; the Aspen fire the next year destroyed some 320 cabins and homes onMount Lemmon, and in 2005, 11 homes were lost in Camp Creek, north of CaveCreek.
Firefighting gel “has a place in wildland fire protection, but I thinkalso this is a key component: If homeowners did work around their house beforethe fire, they wouldn’t have to use gel or foam or any other products,”Summerfelt said. “It may give a false sense of security to property ownersthat that’s all that they have to do.
“If you have to use that on their homes, the appropriate work was notdone before the fire” to clear out vegetation and debris.
“I believe it (gel) probably will be used more in the future,” saidDugger Hughes, wildland-operations specialist with Northwest Fire/RescueDistrict.
He said local fire departments also will be able to use additional gelproducts not yet tested at some point.
Hughes said he has not heard of any municipal fire departments stocking thegels yet, but that “as they become more tested, as they prove their value,I think we’ll start seeing departments stocking the stuff. . . . Most peoplelike myself haven’t used it enough to form any opinion.”
The nice thing about the gels is that they’re durable,” said ShirleyZylstra, a physical scientist and toxicologist at the Missoula center.
The polymers are “the same thing found in baby diapers,” she said.”They have a tremendous amount of ability to hold large amounts of waterrelative to their weight,” and they work like a cooling barrier against thebuilding.
“They kind of insulate it against the oncoming fire, Zylstra added.
The gels will remain effective as long as they retain water, which willdepend on such factors as heat, humidity, wind and the temperatures created byapproaching fire.
They typically can be applied two or more hours ahead of time longer thanfoam now in widespread use, which strong winds also are more apt to blow away.
Testing of gels in the Missoula lab for effectiveness and toxicity to peopleand the environment began about 8 or 10 years ago, Zylstra said.
She said such testing usually takes about two years, and that the market forsuch products usually is small for a few years after that.
They’ve gotten a lot more use in the last three, four, five years,”Zylstra added.
One drawback: The gel is messy, so cleanup can be difficult, she said.
The polymers love water, so once the water evaporates, the polymers will pullwater from the structure,” Zylstra said.
Scraping is one solution, though at least one manufacturer has developed adetergent-type formulation, she said.
Anyone can buy the approved products, Zylstra added.
Hughes of Northwest Fire said it’s likely homeowners in an urban-interfacearea will invest in gels and equipment to apply them.
The Forest Service will use gel agents only on federally owned structures,leaving private property to the discretion of municipal fire departments orlocal homeowners, said Rose Davis, a spokeswoman for the National InteragencyFire Center in Boise, Idaho.