L-Gel decontaminates better than bleach (Fighting ANTHRAX)

US Department of Energy ^ | March, 2002 | Arnie Heller

[Sabertooth]

Hoffman chose colloidal amorphous silica as the carrier material for several reasons. First, unlike crystalline silica, which is toxic, colloidal amorphous silica is safe to use and is found in many household paint formulations. Also, silicon dioxide colloidal particles are commercially available, don't require manufacturing in a special facility, and, because they are chemically inert, are compatible with oxidant solutions. When mixed with the oxidizer, the gel can be applied with simple delivery systems, such as paint sprayers. After application, it thickens and tends not to sag or flow down walls or drip from ceilings. Finally, silica gel materials can be easily vacuumed up after they have dried.

Livermore chemists have extensive experience with colloidal silica gel. From the late 1960s to the late 1980s, the chemists developed a series of extrudable high explosives based on the gelling of energetic liquids. Although this research did not advance to the explosives production stage, the development effort provided useful experience for working with silica-gel materials. It was a logical step to adapt this work to the gelling of aqueous oxidizers for candidate decontaminants, says Hoffman. "Our research with high explosives gave us a good feel for working with silica gels."

Hoffman selected Cab-O-Sil EH-5 fumed silica as the gelling agent. The final formulation was named L-Gel 115, which is a formulation of aqueous Oxone solution gelled with 15 percent EH-5 silica gel. The viscosity can be varied, depending on the application. Under development is a second formulation, called L-Gel 200, which contains 10 percent t-butanol cosolvent to promote penetration on surfaces with heavily coated paint or varnish.

Field tests prove effectiveness

The final L-Gel 115 formulation was subjected to a series of tests at Livermore facilities using surrogates of potential terrorist chemical and biological agents. The tests involved placing surrogate chemical and biological agents on various common materials—varnished wood, painted steel, glass, fiberglass, and carpet—adding L-Gel to the surface, allowing the gel to dry for 30 minutes to several hours, and then determining the percentage of surrogate that had been decontaminated. L-Gel proved greater than 99 percent effective on all surfaces and for all agents.

The Livermore biological researchers also tested L-Gel on safe strains of the deadly biological agents Bacillus anthracis (anthrax) and Yersinia pestis (plague). These strains—Sterne and Strain D27, respectively—could be safely used in experiments because they are nonvirulent, that is, they do not contain the genes that create the lethal toxins present in the real organisms. (See the article entitled Tracking Down Virulence in Plague about research on sources and pathways of virulence in organisms.) The researchers used the agar plate resistance test, a standard technique to measure the efficacy of antibiotics. In this test, about one million cells (or spores, in the case of B. anthracis) were combined with liquid agar, then poured onto a petri dish containing nutrients for cell growth. The strains were also tested against dilutions of L-Gel, which proved more than 99.9 percent effective in killing the cells and spores.

L-Gel also was tested against surrogate spore-forming bacteria in two field exercises. In December 1999, researchers Krauter and Tina Carlsen participated in biological warfare field tests that were conducted by the Soldier Biological and Chemical Command at the U.S. Army Dugway Proving Ground, Utah. The tests compared the ability of several decontamination materials to inactivate surrogate organisms placed on six 40-square-centimeter panels of acoustic ceiling tile, tightly woven carpet, fabric-covered office partition, painted wallboard, concrete slab, and painted metal. Each panel was contaminated with about 10 billion spores per square meter.

After L-Gel was applied, the panels were swabbed about 24 hours later. The number of live spores on most test panels was reduced by an average of 99.988 percent.

Very interesting. The article's almost a year old, but I hadn't seen this information posted.

Colloidal silicon dioxide is the substance used to coat and disperse the anthrax spore in the attacks following 9/11. Clean-up was difficult. Some buildings are still closed, but now ( according to this) we're using the same substance to diperse L-Gel as a disinfectant.

Take that, Saddam... fire with fire.

[Sabertooth]

((((((growl)))))

[Sabertooth]

((((((growl)))))

[Thane_Banquo]

Boom!

[Alamo-Girl]

Thanks for the heads up!

[MHT]

Is Tinactin the same thing? Will this be the next product to disappear from the shelves along with duct tape?

[GOPJ]

bump

[Victoria Delsoul]

Very interesting, indeed. Is this product available on the open market, and do you know how much is it?

Thanks so much for the info.

[Sabertooth]

Is this product available on the open market, and do you know how much is it?

In the raw form, it's sand and ozone. Prices may vary.

[Victoria Delsoul]

Thanks Saber.

[Brad’s Gramma]

Thanks, Saber!!!! Now, where can we buy this? CAN we buy this??

[ppaul]

Now, where can we buy this?

Yeah.
Where?

[kcvl]

News about L-Gel has spread rapidly, and Raber has been interviewed by several newspapers, television stations, and National Public Radio. She has also received a large number of inquiries from emergency response groups across the country interested in additional information and samples.

The developmental work for L-Gel 115 is complete, and Raber's team has begun to develop a new formulation to decontaminate ventilation systems. "Right now, we don't have an easy way to decontaminate air ducts," she says. The team is working on an encapsulation method to aerosolize L-Gel (make it into tiny droplets) so that it could be blown into ventilation systems.

In the meantime, licensing of L-Gel manufacture is well under way, and Raber is hopeful that major organizations will soon have an important yet nontoxic new weapon to counter any biological or chemical attack.

For further information, contact Ellen Raber (925) 422-3985 (raber1@llnl.gov).

[Boot Hill]

From the article:   "Hoffman selected Cab-O-Sil EH-5 fumed silica as the gelling agent."

Interesting! Cab-o-Sil is also an ingredient used in the production of anthrax spores!

--Boot Hill

[SLB]

Guess I better get the plexiglass dome up and sealed. Maybe I am uninformed, but I just do not see a huge threat to where I live, or you LLD, from chemical agents. Now, if I lived in NYC or LA maybe so, but not in rural country. We might have problems with other things such as water supplies or food supplies, but I cannot see anyone interested in getting more bang for the buck using VX or mustard here.

[snopercod]

Geez', I had a couple gallons of CAB-O-SIL in the shop that I used once on a fiberglass part. Figuring it would never be needed again, I tossed it. (You buy the stuff at aircraft hombuilding stores, like Aircraft Spruce).

During the first anthrax scare, FReepers found a commercially-available decontaminant. I took a printout of it's specificatations down to the county hazmat guys where I live. Now, I seem to have forgotten what it was...

[Lion Den Dan]

I just do not see a huge threat to where I live, or you LLD, from chemical agents.

Hard to say. Army sent me to megga Chem school in 1972. From that training, unless the chem strike was right on top of you, dispersion would reduce or eliminate the risk for the agents I know about. Mustard, though, is something else. It is persistant as all get out and settles in low places, there to remain forever, I guess.

[SLB]

When my son came home from work last night he said they were talking about the incease in sales they have had for plastic and duct tape.

[Thane_Banquo]

Nah. I don't know what L-Gel is.

[harpseal]

Re: Chem and Bio weapons against small town America. As you know a chemical or bio weapon works best against a dense population of enemy. Dilution is one of the primary safeguards against becoming a chem or bio casualty. If milligram is deadly then a nanogram or picogram is probably not a problem. The dispersion of the active agent is done of an area. A liter/sq mile is a good means of measurement. Due to the dispersion of the population in small towns the bad guys might cause a hundred casualties with the same amount of agent that in a city would cause 100,000 casualties.

When it comes to more conventional terrorism it just may be that small towns will be viewed by the Terrorists as potentially more inviting targets. Much smaller police forces cover a significantly larger area. Thus from casuql glance by someone unfamiliar with the details of American culture it would seem a small town would be a much better place to drive in shoot some Americans and drive out.

Should the tangos try this they just might get a very unexpected response. I know I would takwe it as a personal affront if someone started shooting people in my local supermarket and I would be upset enough to make my displeasure known to the terrorist in a 185gr complaint.