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plane dropping fire retardant

Fighting Fires With Corn

–By Liz Morrison
The fire starts as a small yellow flame licking up from a pile of debris in an old wooden garage. Soon, orange flames are leaping high as black smoke fills the structure. A few seconds later, a bank of flames rolls along the ceiling and boils out the open door.

The entire structure is engulfed in flames and smoke when firefighters hit the blaze with a new corn-based fire-suppressant gel, called TetraKOTM. With a few blasts from the fire hose, the flames disappear, and a dense cloud of billowing steam fills the building. In seconds, the fire is out. The firefighters have used just 16 gallons of water mixed with TetraKO to quench the roaring blaze.

The demonstration burn, recorded on video, shows the firefighting power of TetraKO, a biodegradable water enhancer made by the South St. Paul, Minnesota, startup EarthClean Corporation. TetraKO changes plain water into an adhering gel that knocks down fires faster than water or foam — without harming the environment or wildlife. EarthClean, founded by veteran Minnesota entrepreneur Doug Ruth, launched TetraKO this year into the $6 billion global fire-
protection market.


Patented TetraKO is a powdered concentrate composed of cornstarch and proprietary thickening agents, explains Doug Root, AURI analytical chemist, who has worked with the company on bench tests. TetraKO is mixed directly into fire truck water tanks, where it turns water into a gel the consistency of hand sanitizer. The gel converts to a free-flowing liquid when it’s pumped under pressure through standard firefighting equipment.

After TetraKO leaves the fire hose nozzle, it reverts to a gel, which “sticks and stays” to walls, ceilings, roofs and other surfaces, providing a thick blanket of fire protection that doesn’t run off like water or foam. When heated by flames, TetraKO releases a cooling steam, which helps smother the fire and dramatically cuts the risk of rekindling.

On wildland fires, TetraKO clings to bushes, trees, and grasses for hours without falling to the ground, creating a fire barrier that can be applied from the air, trucks or backpack sprayers.


TetraKO “could revolutionize fire department operation,” says Nyle Zikmund, chief of the 60-member Spring Lake Park-Blaine-Mounds View Fire Department, which has been field testing TetraKO for more than a year.

Firefighter safety is the number one benefit, says Chief Zikmund, who also serves on the board of the International Association of Fire Chiefs (IAFC). Independent tests performed by EFI Global, an engineering and fire investigation service, found that TetraKO was 91% more effective in knocking out structure fires than water alone, and 86% more efficient than foam. This improved knockdown power lets firefighters attack the fire defensively, from a much safer position outside of the building.

It also cuts firefighting costs, Zikmund says: “Smaller trucks, smaller crews, less time on the scene, lower labor costs and less potential for injuries.” It takes significantly less water to put out fires with TetraKO, too, he says. That minimizes water damage to buildings. And the cost per gallon of mixed solution of TetraKO is about half that of firefighting foams, Ruth says.


Doug Ruth founded EarthClean Corporation, a South St. Paul, Minnesota, start-up that launched TetraKo

TetraKO was invented and patented by three retired Minnesota engineers and a firefighter. EarthClean bought the rights to the new technology in 2009 and founded EarthClean to commercialize
the invention.

Before investing in TetraKO, Ruth spent months researching the market for fire suppressants. Firefighters today use foams, retardants and additives to improve water’s effectiveness, but these products come with serious drawbacks, including high costs and negative environmental consequences.

By contrast, TetraKO doesn’t use toxic chemicals and won’t corrode equipment. It’s been independently certified as non-toxic to plants, fish and mammals, according to National Fire Protection Association standards (NFPA) and higher European standards. The technology has been independently tested to the EPA Office of Prevention, Pesticides and Toxic Substances (OPPTS) standard and verified to be as “ready biodegradable,” EPA’s top rating. Unlike other firefighting gels, TetraKO doesn’t contain super absorbent polymers, which don’t biodegrade. In fact, it’s the first fire suppression tool to receive the Environmental Protection Agency’s Design for the Environment (DfE) certification, which recognizes environmentally safe chemical products.

Ruth’s market research convinced him that TetraKO was very different from anything else currently available to fight fires. “I saw an opportunity to bring a new fire suppressant to the market.”


Under Ruth’s leadership, EarthClean has raised $4.2 million in equity capital. The startup worked with Aveka Group, a particle processing and research company in Plymouth, Minn., to finish product development and testing. Now, TetraKO is being field tested by about a dozen Minnesota fire departments.

The firefighting gel was also tested last fall by Texas A&M’s Engineering Extension Service (TEEX) at the internationally-recognized Brayton Fire Training Field. The tests included aerial drops on simulated wildland fires, and side-by-side comparisons with water and foam on structure fires.

TetraKO is a biodegradable water enhancer that changes plain water into an adhering gel that knocks down fires faster than water or foam

The Texas demonstrations prompted a white paper from the Technology Council of the International Association of Fire Chiefs, which concluded that “TetraKO has the potential of not only increasing the effectiveness of both wildland and structural firefighting, but doing so in a more environmentally friendly manner — a true win-win for the fire service.”

AURI is currently working to help EarthClean develop TetraKO as a Class A fire retardant and obtain USDA Forest Service certification, which will allow TetraKO to be used on federal wildland fires. The next phase is for AURI and EarthClean, with the help of the Minnesota Corn Research & Promotion Council and Minnesota Soybean Research & Promotion Council, to develop and certify a Class B or Class A and B fire retardant.

AURI staff are also helping the company develop a liquid version of TetraKO, which could be proportioned at the hose as needed. A liquid concentrate would be more acceptable to municipal fire departments than the current batch mix product, Chief Zikmund says.


TetraKO is being manufactured in Minnesota through multiple toll-blending manufacturers. EarthClean, which employs eight people, is now building a distribution network and projecting first year sales of about 40,000 pounds of concentrate.

“Starting a new company is a daunting task,” Ruth says. “As an entrepreneur, you have to be totally passionate about what you’re doing. I was interested in finding technology that makes a positive difference. I see this technology as a way to change how the world fights fires.”

To see TetraKO in action, go to:

AURI and EarthClean

Idea to opportunity: EarthClean needed certification by the USDA Forest Service in order to use their corn-based firefighting product TetraKO to fight forest fires. The company also wanted to develop a liquid version of TetraKO that would work better for municipal fire departments

Outcomes: With testing and product development help from several AURI scientists, EarthClean plans to have commercial quantities of TetraKO powder available for the 2012-13 wildfire season, and work on the liquid version of the firefighting product is well underway.

Funding Partners: A special thanks to our funding partners Minnesota Corn Research & Promotion Council and Minnesota Soybean Research & Promotion Council.