From the Decomposition of Chemical Warfare Agents to the Decontamination of Cytostatics

The need to protect the environment and reduce greenhouse gases emissions is currently a main global objective among stakeholders and policymakers. Metal oxides have been widely used to decompose hazardous substances into nontoxic products. However, owing to their slow reactivity, recent studies have focused on increasing the reaction rate to suit the current practical applications. For example, in previous studies, sulfur mustard, VX and soman were decomposed by using ferrihydrite and nanoscale anatase. Currently, various dopants such as mixed oxides are used in doping titanium dioxide to increase their stoichiometric activity. The result is an excellent degradation of soman and VX attributed to the defects in the crystal lattice induced by the Ce³⁺ atoms.

Recent nanotechnology evolution has proposed the reduction of sizes of the particles to nanoscale levels. Such nanostructured materials can be utilized in various decontamination applications like the military components. For instance, cytostatics which comprises of nitrogen mustards and their derivatives can be decomposed effectively by employing these nanomaterials. In fact, the role of the nanomaterial in the measurements against fog incorporated chemical warfare contaminants is currently being accessed in an EU project.

A group of researchers led by Professor Štengl Václav from Department of Material Chemistry, Institute of Inorganic Chemistry ASCR in the Czech Republic compared and contrasted the degradation activities of titanium (IV) oxide-based samples to that of commercial FAST-ACT products on chemical warfare agents (CWA). Their work is published in the research journal, Industrial and Engineering Chemical Research.

Generally, FAST-ACT are high-performing and nontoxic materials used for neutralizing toxic chemicals in various applications. They can also be used for degrading chemical warfare agents.

The authors observed that the prepared samples were excellent in decomposing CWAs as compared to the commercial FAST-ACT products. This was attributed to the first kinetics and high conversion degrees. To be precise, for samples containing 2.0 wt% of Ge and that doped with Zr⁴⁺, the reported degree of conversion were: 99% for VX, 100% for soman, and 95% for Sulphur mustard.

The presented destructive metal oxide sorbents were provided as an alternative in this case. It incorporated several improvements that positively impacted on the reaction and final product obtained. This included scaling up the decomposition of sulfur mustard from laboratory provided conditions to reaction condition. Consequently, the test results showed that the addition of water to the reaction mixture resulted in a significant reduction in detoxification and especially in the VX and soman cases. However, for sulfur mustard derivatives, no significant change in the detoxification was observed on addition of water because they have similar detoxification efficiency as that of water.

The objective of their study was not to replace the conventional methods, like commercial FAST-ACT, for decomposing chemical warfare agents and other toxic substances. Professor Štengl Václav and his colleagues wanted to develop an alternative efficient method that exhibits high reaction rates and efficiency with limited challenges for current practical applications which was indeed a success.