News | Apr 17, 2019

The air filter in ’10 Cloverfield Lane’ was critical for survival–the US Army agrees

Army researchers have invented an end-of-service-life indicator so we know when to change out the filter

Courtesy Paramount Pictures

Waiting out an apocalyptic alien invasion in your bomb shelter, like Howard in the film “10 Cloverfield Lane,” isn’t easy.

Survival depends on stockpiles of food, water, board games, and, as the film highlights, a collective protection air filtration system.

“I’m not sure yet if it’s chemical or nuclear,” says Howard, played by actor John Goodman. “But down here we’re safe.”

In real life, the readiness of these building-wide filters to stop a long list of toxins is critical for the military, which is why U.S. Army researchers at the Chemical Biological Center have been advancing their capabilities.

On Tuesday, Army researchers Gregory Peterson, Joseph Rossin, Jennifer Soliz, and Kathryn Killops were issued U.S. Patent 10,261,022 for novel zirconium hydroxide chemistry that allows an air filter to change colors as its filtering capacity decreases, providing an accurate indication of its residual life. Scientists call this colorimetric analysis.

“Air purification, including individual and collective protection filtration, is of major concern to the military, first responders, and industrial workers,” the patent states. “Filters typically containing activated, impregnated carbons are employed to filter toxic chemicals, and have limited lifetimes after exposure. Furthermore, due to interaction with environmental contaminants, such as low-level concentrations of sulfur oxide, nitrogen oxide, hydrocarbon vapors, etc., the capacity of filters can degrade even before a toxic chemical event.”

There are respirator cartridges with indicator technologies already being sold commercially; however, the Army says they have problems, including poor sensing of reactive gases and insufficient reactivity.

“Due to continuous operation of filtration devices, ambient and battlefield contaminants decrease physical adsorption and chemical reactivity of the filter material over time due to interactions with the pore structure and/or the impregnants associated with the filter material contained within the filter housing, such as for example activated carbon impregnated with salts of copper, zinc, molybdenum and silver, plus triethylenediamine, according to the Army’s patent.

“Residual life indicator technologies have been developed; however, most do not accurately determine the effects of acidic/acid-forming contaminants on the residual life of the filtration media.”

In coordination with the Army’s technology transfer office, TechLink is seeking businesses that could benefit from the Army’s research by licensing the indicator chemistry for integration in commercially available products.

TechLink is the Department of Defense’s partnership intermediary for technology transfer, providing businesses with no-cost licensing services and guidance through the technology transfer process.

Marti Elder, an invention licensing expert at TechLink who works closely with the Chemical Biological Center, is facilitating industry engagement with the lab.

Elder said this was just one of several recent inventions related to advanced filtration capabilities enabled by the Army’s research on metal-organic frameworks.

“Industry partners can help the Army transition the technology back to the warfighter and, in dual-use cases like this, possibly improve commercial sales by enhancing existing product lines,” Elder said.

Licensing inquires can be directed to Marti Elder at or 406-586-7621.