Sudsy brew neutralizes viral, bacterial, nerve agents in minutes
By John German
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A better option may be available soon. Researchers in Developmental Technology Dept. 6803 have created a foam that begins neutralizing both chemical and biological agents in minutes. Because it is not harmful to people, it could be dispensed on the disaster scene immediately, even before casualties are evacuated.
The all-in-one decontaminating foam soon may be the best first response available in the event of a chem-bio attack. "Whatever you do, it's best to act very quickly," says Maher Tadros (6803). "This foam can start neutralizing an agent or combinations of agents right away, even before you know what you're dealing with."
The US has a number of strategies to prevent a chemical or biological attack from ever occurring in this country, says Greg Thomas (8120), Sandia program manager for chem-bio nonproliferation. "But if we are attacked," he says, "we'll need to have the tools available to respond."
One decontaminant does it all
In laboratory tests at Sandia the foam destroyed simulants of the most worrisome chemical agents (VX, mustard, and soman) and killed a simulant of anthrax -- the toughest known biological agent.
Against the anthrax simulant, the foam achieved what the researchers call a 7-log kill -- after one hour only one anthrax spore out of 10 million is still alive.
International law prohibits the Sandia researchers from possessing real chemical or biological agents, but they have taken samples of the foam to the Illinois Institute of Technology Research Institute in Chicago where the foam was tested against actual nerve agents VX, mustard gas, and soman. In those tests the foam neutralized half the remaining chemical agent molecules every 2 to 10 minutes, depending on the agent. For most chemical agents the contamination remaining after one hour of exposure to the foam is insignificant. The foam neutralizes viral particles in minutes, as well.
"It has performed superbly against all the agents tested," Maher says.
More tests planned for April will pit the foam against real anthrax and other bacterial spores.
"If you can kill spores, you can kill germinating bacteria and you can deactivate viruses," says Mark Tucker (6803). "Spores are the most difficult biological agents."
The foam -- a cocktail of ordinary substances found in common household products -- neutralizes chemical agents in much the same way a detergent lifts away an oily spot from a stained shirt.
Its surfactants (like those in hair conditioner) and mild oxidizing substances (like those in toothpaste) begin to chemically digest the chemical agent, seeking out the phosphate or sulfide bonds holding the molecules together and chopping the molecules into nontoxic pieces.
How the foam kills spores -- bacteria in a rugged, dormant state -- still is not well understood, Mark says. He suspects the surfactants poke holes in a spore's protein armor, allowing the oxidizing agents to attack the genetic material inside. The research has been presented at various technical conferences, including the Scientific Conference on Chemical and Biological Defense Research at Aberdeen Proving Ground, Md., Nov. 17-20, 1998, and the National Research Council Workshop on CBW Physical Protection and Decontamination in Washington, D.C., Jan. 25-26, 1999.
Sandia has filed for a patent on the foam, tentatively called Decon Foam 100.
Effective, benign, inexpensive
Currently available sprays, fogs, or other decontaminating products typically are based on bleach, chlorinated solvents, or other hazardous or corrosive materials, Maher says. And many new and emerging decontaminants are designed to work against only a limited number of either chemical or biological agents.
They also are expensive, he says. A new nerve-agent decontaminant made in Germany, for example, costs about $150 a pound. The Sandia foam, in comparison, could be produced for about 15 cents a pound.
As it expands to about 100 times its liquid volume through a special nozzle that draws air into the spray, it fills space and automatically seeks contact with chemical or biological agents in crevices and other hiding places, or in the air for airborne agents. In several hours the foam collapses back to its compact liquid state and, in theory, is benign enough following a chem-bio incident to be washed down the drain like dish soap.
"The foam gets around the traditional approaches that have high water demand and use more damaging chemicals," says Greg. "It also offers an 'all-in-one' approach that would greatly simplify deployment considerations."
Like a fire retardant, the foam could be sprayed from handheld canisters. (It also works as a fire retardant.) For open areas, airports have trucks that can dispense foams over runways.
Ideally, tanks of the foam could be incorporated into the fire sprinkler systems of high-profile government buildings or other potential targets -- embassies, congressional buildings, the White House, subways, and the New York Stock Exchange, for instance.
"That's the best scenario," he says. "You could flip the switch as you evacuate and begin decontaminating immediately." Several government organizations including Sandia are working to develop sensors that would automatically detect and identify contamination by a chemical or biological warfare agent.
The more the better
The foam is more effective at neutralizing combinations of chem-bio agents than other existing or emerging decontaminating agents, Maher says. But, he adds, this is not a competition. "The more products we have available, the better," he says.
Maher cautions that much research and independent testing need to be done to verify the foam's effectiveness and ready it for real-world applications and acceptance. Rita Betty and Joanne Paul (both 6803) continue to test and refine the foam in the laboratory. (Paul Baca, 1845, also has been involved in its development and testing.)
Already Sandia is working with the US Army, the Los Angeles Police Department, Los Alamos and Lawrence Livermore national laboratories, the New York and Washington, D.C., subway systems, and the San Francisco international airport to identify places where the foam might be deployed initially.
DOE is funding development of the foam as part of its larger Chemical and Biological Nonproliferation Program. The program seeks to develop intelligence capabilities, sensors, and other technologies that allow the US to detect, deter, and respond to terrorist attacks involving weapons of mass destruction.
Last modified: March 12, 1999
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