New Spray Catch Terrorists “Red-Handed”

Researchers from the Hebrew University in Jerusalem, Israel have recently developed a spray which can easily detect traces of explosive materials. In order to prevent terrorist activities, which have been increasing throughout the world, security forces must be able to detect traces of explosive materials. Theoretically, since anyone who works with explosives retains a small amount of the explosive substance on his hands, it shouldn’t be a problem to discover these traces. However, in practice, this is a very difficult task. A major advantage of this new spray is that unlike other sprays on the market, its production is relatively cheap.

Professor Josef Almog (Credit: the Hebrew University of Jerusalem)
Professor Josef Almog
(Credit: Hebrew University
of Jerusalem)

Professor Josef Almog of the Hebrew University, Jerusalem, has developed a new spray that can identify the chemical presence of Urea Nitrate – a powerful home-made explosive material. The detection process is extremely simple. The suspect’s hands are wiped with a sponge, which is then sprayed with the new explosives detection spray. If urea nitrate is present, the sponge turns red.

Urea nitrate is an improvised explosive, which is often used by al-Qaeda and the Palestinian terrorist organizations. For example, urea nitrate was the explosive material used in the first bombing of the World Trade Center in 1993. Amateur chemists can easily produce large amounts of urea nitrate and can apply it in home-made landmines and suicide bombers’ kits. It is common knowledge that such explosives have caused numerous deaths. The crystalline, sugar-like appearance makes the identification of urea nitrate very difficult. Because it resembles sugar so much, it is almost impossible to positively identify the substance without chemical analysis. The new, easy to use spray has the potential to save the forensics and the security forces a lot of time and trouble.

The project was supported in part by the US/Israel Bilateral Committee on Counter-Terrorism, and besides its obvious importance for legal procedures may help improve our understanding of the chemistry of urea nitrate. Although instruments for detecting the substance already exist, they are much more complicated and quite expensive. The new spray is cheaper and is capable of detecting even minute traces of the improvised explosive on the hands of suspects, door handles, luggage containers and vehicles. Prof. Almog claims it is only a matter of time before it will be used on a regular basis by law enforcement agencies.

The red color implies a positive reaction with the presence of urea nitrate. (Credit: Professor Josef Almog)
The red color implies a positive reaction
with the presence of urea nitrate
(Credit: Professor Josef Almog)

Almog has a long history of inventing color-changing test fluids for the security forces. Himself a former Police Brigadier General and former Director of the Identification and Forensic Science Division of the Israeli Police, he uses his knowledge of field-work as well as his expertise in chemistry to develop new forensic technologies.

In 2006, TFOT covered the development of TATP identification (another deadly improvised explosive), in the form of a pen-like device developed by researchers from the Technion in Israel. Another interesting TFOT report on a threat identification technology was the BioPen, which can be used to detect bio-warfare agents and also has medical applications.

For more information about Professor Almog’s work, see the Hebrew University’s official press release.