L-Gel Decontamination Reagent
L-Gel is a coating that was developed at Lawrence Livermore National Laboratory (LLNL) in Berkeley, California. The coating is effective at decontaminating areas exposed to both chemical and biological agents. As such, L-Gel is potentially applicable to forensic science, both in the decontamination of a crime scene and in the pathologist's laboratory.
The need to decontaminate spills of liquid or powdered poisons or infectious organisms is potentially urgent. In order to prevent injury from chemical or biological warfare agents, for example, the source agent must be contained before anyone touches the material, or before the agents become dispersed in air currents.
The development of L-Gel began in the 1990s. Among those striving to develop a nonhazardous, portable, and inexpensive decontamination reagent were LLNL researchers. Their L-Gel formulation incorporates a chemical compound called potassium peroxymonosulfate into a material called silica.
Potassium peroxymonosulfate is an oxidant. That is, it contributes an electron to the chemical bonds of the target compound, which disrupts the bonds that hold the target together or make it active. Bleach is another oxidant. However, bleach produces noxious fumes, making its use in confined settings dangerous. Bleach is also corrosive, and could damage equipment and tissue that is being decontaminated.
The oxidant is incorporated into a gel. The thick gel is able to cling to surfaces better than water, and remains where it has been applied. A water-based solution will spread out and could even run down an inclined surface, which could further disperse the poison or infectious microbe. Another advantage of a gel is that the oxidant is kept in contact with the target longer than would be possible if the oxidant was dissolved in water.
L-Gel is effective at killing over 99% of populations of bacteria including Bacillus anthracis (the bacterium that causes anthrax) and Yersinia pestis (the bacterium that causes plague). Surfaces as varied as carpet, wood, and stainless steel are all efficiently decontaminated with L-Gel.
