California is still working to recover from the deadly 2018 wildfire season, when nearly 100 people died and tens of thousands of structures ignited in blazes around the state. As average global temperatures continue to rise, experts are pointing to a hot, dry future where wildfires occur earlier and with increased ferocity. Already, half of the largest fires in California’s history have occurred in the last five years.
For a century, the goal of firefighting has been suppression — stamp out all fire regardless of cost — and there have been few changes in the technology used to fight fires. But as many who work in fire research and prevention contend with the inevitable future, they are reassessing how and when we fight fires.
“Most people think that fires just sort of start willy nilly anywhere in the forest,” said Eric Appel, materials scientist at Stanford University. “But it turns out that that’s not really true.”
Appel is senior author on a new study published today in Proceedings of the National Academy of Sciences, reporting on the first field trials of a long-acting, environmentally-benign fire retardant that he hopes will reshape the way fires are prevented and fought in California.
“What we’re attempting to do is to completely change how you’re using [fire] retardants,” he says.
The study found that most wildfires start in the same locations, and that the retardant will protect an area for months.
“So what that means,” Appel says, “is that you would only need to treat a very small amount of land in order to prevent a majority of fires.”
The Spark of An Idea
For co-author Jesse Acosta, adjunct professor of Natural Resource Management at Cal Poly San Luis Obispo, a moment of inspiration came years ago, as he stood in the sweltering heat of Hawaii, working for the U.S. Forest Service in a Smokey Bear costume, trying to convince people to care about fire prevention.
“I don’t know if it was the actual discomfort of the suit that made me think about things differently, or if it was some sort of late-night epiphany,” said the former Fire Prevention Forester, “but it became very clear to me very quickly that [outreach] was not effective in terms of preventing fires.”
Likely, it was both, but it would take a move to Connecticut and a chance meeting with a colleague for the building blocks of a new approach to fall into place.
At the time, Eric Appel, now a materials scientist at Stanford University, was studying medical drug delivery at MIT, “answering the question of ‘How do we keep these drug molecules stable and get them where they need to go and keep them where they need to be?'”
The answer lead to the development of a “hydrogel” made of inexpensive, renewable, and benign materials that could deliver medications in a human body and keep them stable over time. For example, an early application allowed people with diabetes to receive a single injection that supplied insulin over six months.
Hydrogels themselves may seem an unlikely hero: they’re pale, shapeless blobs reminiscent of thick shampoo or mayonnaise. You mix them up in buckets, foregoing a lab coat for rubber boots. But to Appel, their beauty lies in the thoughtfulness of their design.
“The gels we’re making are sophisticated and scalable. They form from simple components,” Appel. “And they function like molecular Velcro,” meaning they can change their properties to allow them to be sprayed easily from a needle or nozzle.
Acosta was aware of Appel’s hydrogels and thought about what might happen if you replaced medications with a “molecular cargo” of flame retardants.
“It was around midnight when it finally dawned on me to use these hydrogels,” Acosta said, pointing out the many commonalities shared between what makes something safe for the human body and what makes something environmentally benign. “Let’s wrap up fire retardant in these hydrogels and see if they are able to stick to fuels and persist through weather.”
Out of the Lab and Into the Fire
After this unlikely series of events, Appel, Acosta and collaborators received funding through Stanford’s Realizing Environmental Innovation Program.
Appel and his collaborators began working withCal Fire to identify where fires start each year. They found fires reproducibly start year-after-year in the same places, calculating that 84 percent of wildfires in California in the last 10 years have started at high-risk roadside spots or with utilities infrastructure.
Following the success of a pilot study on small piles of pine shavings, this new study tests hydrogel performance on a larger scale.
They treated plots of native grass 10 feet long and 10 feet wide with their product and set both those and untreated control plots alight, watching how they burned.
“They just explode,” Appel said of the control plots. “It’s a pyromaniac’s best afternoon.”
Appel and Acosta also wanted to address a major shortcoming of current retardants — that they are not meant to persist long beyond their initial application.
In fact, much of the millions of tons of retardant that planes drop onto fires each year are rendered useless by subsequent dumps of water onto active fire-lines. Even heavy dews and fogs, common along the California coast, can decrease the retardants’ efficiency.
The hydrogel, by contrast, stays at full potency and continues delivering fire protection over months of the traditional fire season. The hydrogels also stand up to dew, fog, and moderate rain, although they are intentionally designed to wash away at the start of the wetter fall months.
“You can put 20,000 gallons of this on an area for prevention, or 1 million gallons of the traditional formulation after a fire starts,” said study lead author Anthony Yu, a PhD student in materials science and engineering at Stanford, in a media release.
The New Reality of Fire in California
According to Acosta, a policy of suppression and a cultural view that fire is villainous has pitted the country against a future where extreme fires are guaranteed. This is due to a massive buildup of fuel — dead trees, brush, and chaparral — in an ecosystem which has historically required fires as a natural part of the landscape.
“Every fire we fight, every fire that happens, has the potential to be the Mendocino Complex or the Thomas Fire or the Carr Fire or the Ferguson Fire.”
And the economic costs of fighting fires have become enormous. Last year the federal government spent $3 billion to put out blazes. Local agencies are also strapped. Fighting fires and defending one hot, 4-mile stretch along Highway 118 in Ventura County costs an average of $5.5 million annually.
The true importance of hydrogels, Acosta says, extends beyond their use as a long-term, environmentally benign treatment. By stopping fires from ever starting, it pushes the balance of power farther into our favor.
“We can stop fighting these catastrophic fires in June and July, Acosta said, “and fight them on our terms with prescribed burns in cooler, wetter weather and during times when we have more money freed up for fighting fires.”
In the next week, crews will apply the long-term fire retardant to some of Highway 118 and two other stretches of road in San Diego County. These will be the first large projects of a company formed to promote the retardant, which is now sold as FORTIFY™.
Wes Bolsen, president and CEO of Ladera Tech, estimates roadside treatments will cost the state Department of Forestry and Fire Prevention (Cal Fire) and the Department of Transportation (Caltrans) between $20,000 and $200,000, depending on the mileage and other factors.
Bolsen says utilities have also expressed interest in the retardant.
Projects such as this may signal the first drop in a flood of new tools and methods aimed at developing a more holistic approach to accommodating fires in the state. Acosta feels hopeful because ultimately everyone he has worked with — from politicians to firefighters to loggers — are working toward a common goal.
“These new technological advances,” he said, “are giving us the power to make new and better decisions.”