The evolution of the threat concept for explosive devices has driven the technical capabilities of these Explosive Trace Detectors (ETD’s) which are now deployed in their thousand globally.

The aviation security industry and emergence of national and international testing agencies who now specify the type of substances needing to be detected, to what sensitivity levels and specific operational resilience to false or nuisance alarms has driven ETD manufactures to develop solutions that only address these specifications.

Unfortunately terrorists do not follow such rigorous specs and have steadily moved away from the common use of substances that are easily and reliably detected by existing deployed technologies and towards substances that are less difficult to obtain and existing equipment is not able to detect.

Home Made Explosives (HME’s) are now the primary threat to all environments where it is required to prevent improvised explosive devices (IED’s) entering and it has been noted by the various security agencies that not all HME’s are detectible by the ETD’s that have been available on the market.

Common use of Peroxides, Nitrates, Chlorates and Perchlorate substances, easily purchased from internet suppliers and manufactured at home or clandestine labs into very potent HME’s is now the primary concern as shown by data below published by the US by the Alcohol, Firearms and Tobacco Agency (AFT) through their subsidiary organisations of US Bombs Data Centre (USBDC) and the Bomb Arson Tracking System (BATS)

Detection Limitations and Solutions

Although some peroxide based compounds such as TATP are detectible by existing ETD technology the limitations of the science behind these instruments means that Fuel Oxidisers, Pyrotechnics and other inorganic substances are not.

Both IMS and MS based ETD’s rely on vapour analysis techniques that require a vapour to be generated from a solid sample collected on a sample trap or swab. The thermal desorption process is therefore focussed on generating vapours from organic explosive substances defined by international agencies. These substances generally have a boiling point of around 200c

Inorganic substances generally have boiling points much higher than 200c which  means that the core technologies currently utilised in practically all approved ETD’s on the market is not presented with sufficient vapour to analyse. These inorganic families of Nitrate, Chlorate and Perchlorate compounds make up more than 80% of all the explosive incidents that have been recorded and analysed in the last 10 years so it has been necessary to look for new detection solutions that address this gap in the detection spectrum.

GreyScan’s innovative ETD-100 is the worlds first, field deployable ETD specifically designed to detect inorganic Nitrates, Chlorates and Perchlorate compounds. Using the lab proven capabilities and reliability of Capillary Electrophoresis (CE), GreyScan, working in partnership with the University of Tasmania has developed a small, portable desktop system that not only delivers unrivalled detection standards as a stand alone instrument but also allows for complimentary deployment alongside existing IMS based ETD’s. GreyScan’s patented Capillary Zone Electrophoresis (CZE) detection process requires a liquid solution sample rather than a vapour phase specimen meaning that inorganics are dissolved into proprietary fluid reagents and analysed overcoming the issues around creating a vapour. Additionally, clear down times from an alarm state are far more reliable than vapour analyser type ETD’s

ETD of the Future

It is clear from the science of the various solutions already available and the challenge of emerging threats and more innovative terrorist chemists and operators that a single technology product that offers high definition detection capability for all substances is currently not available.

Future ETD systems need to be able to detect all current and newly defined threat substances with the added capacity to increase detection libraries to cover other threats as they emerge. Indeed these new threats may not be explosive materials at all but other chemicals that are able to cause damaging effect to people in various environments, including aviation.

GreyScan continues to work with cutting edge technology partners to design and develop a single box solution to all perceived threats, current and future, that may be countered by trace detection.

In the meantime, the ETD-100 offers a detection solution that fully compliments existing detection capabilities.

Deployed alongside IMS or MS based detection devices, it is possible to create a detection CONOPs that successfully covers the detection demands from organic and inorganic threats.

Inorganic Enabled X-Ray Alarm Resolution

In addition to the stand alone capabilities of the ETD devices, ETD-100 offers potential alarm resolution solutions to the planned implementation of enhanced cabin baggage screening processes, where Ai driven CT based X-Ray machines, now being deployed in airports across the world, are able to themselves discriminate between organic and inorganic substances and alarm criteria set for each.

Reliable and accurate resolution processes need to be introduced to allow cabin baggage that triggers an inorganic threat alarm in a CT X-Ray system to be double checked and cleared (or not) before being passed back to a passenger.

The ETD-100 is currently the ONLY ETD instrument that offers this capability.

Find out more at www.greyscandetection.com