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 for all the agents we have tested it against," Tadros 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 foam co-developer Mark Tucker of Sandia. "Spores are the most difficult."
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, Tucker adds. The researchers suspect the surfactants poke holes in the spore's protein armor, allowing the oxidizing agents to attack the genetic material inside.
Research papers on the work have been presented at various technical gatherings of the chem-bio defense community, most recently at the National Research Council Workshop on Chem-bio Warfare Physical Protection and Decontamination in Washington, D.C., Jan. 25-26.
Sandia has filed for a patent on the substance, tentatively called Decon Foam 100.
Effective, benign, and inexpensive
Currently available sprays, fogs, or other decontaminating products typically are based on bleach, chlorinated solvents, or other hazardous or corrosive materials, Tadros says. And many new and
Contact: john german
DOE/Sandia National Laboratories