“Fooling fido”—chemical and behavioral studies of pseudo-explosive canine training aids

Abstract

Genuine explosive materials are traditionally employed in the training and testing of explosive-detecting canines so that they will respond reliably to these substances. However, challenges arising from the acquisition, storage, handling, and transportation of explosives have given rise to the development of "pseudo-explosive" training aids. These products attempt to emulate the odor of real explosives while remaining inert. Therefore, a canine trained on a pseudo-explosive should respond to its real-life analog. Similarly, a canine trained on an actual explosive should respond to the pseudo-explosive as if it was real. This research tested those assumptions with a focus on three explosives: single-base smokeless powder, 2,4,6-trinitrotoluene (TNT), and a RDX-based plastic explosive (Composition C-4). Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we determined that the volatile compounds given off by pseudo-explosive products consisted of various solvents, known additives from explosive formulations, and common impurities present in authentic explosives. For example, simulated smokeless powders emitted terpenes, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite. Simulated TNT products emitted 2,4- and 2,6-dinitrotoluene. Simulated C-4 products emitted cyclohexanone, 2-ethyl-1-hexanol, and dimethyldinitrobutane. We also conducted tests to determine whether canines trained on pseudo-explosives are capable of alerting to genuine explosives and vice versa. The results show that canines trained on pseudo-explosives performed poorly at detecting all but the pseudo-explosives they are trained on. Similarly, canines trained on actual explosives performed poorly at detecting all but the actual explosives on which they were trained.

Detection of prohibited treatment products on racing tires using headspace solid phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS)

“…2-Ethyl-1-hexanol also registers among the most telltale compounds, and is a known hydrolysis product of the plasticizers bis(2-ethylhexyl) phthalate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) sebacate. [13][14][15][16] In a number of products, the 2-ethylhexyl moiety is present in the form of benzoic acid 2-ethylhexyl ester, suggesting a possible source of origin.…”

Author's response to Sanchez et al. entitled “On the importance of training aids and the definition of an explosive odor signature: Commentary on Kranz et al.”

“…These canines did not reliably respond to authentic Composition C-4. Conversely, canines imprinted on authentic Composition C-4 did not reliably respond to either of the training aids [2].…”

Improvements in the vapor-time profile analysis of explosive odorants using solid-phase microextraction

“…A 25 critical aspect of successful canine detection relies on well-controlled initial and 26 maintenance training protocols. For example, Kranz et al [1,2] recently reported that 27 canines varied in performance when trained using different training materials. However, 28 use of contraband materials as training materials requires care in storage and chain-of-29 custody.…”

“…Alternative training aid materials (often termed pseudo-, mimic, or simulant 30 training aids) contain the characteristic odorants of the hazardous materials, but in a form hazardous materials [3]. Although the use of non-explosive training aids as replacements 1 for real explosives have yet to be widely accepted by the canine detection community, the 2 development of these alternative training aids would greatly facilitate canine training. 3 Developing alternative training materials not only requires presenting the key 4 characteristic odors, but also requires knowledge about the longevity of the odor release 5 by the training aid.…”

“…3 Developing alternative training materials not only requires presenting the key 4 characteristic odors, but also requires knowledge about the longevity of the odor release 5 by the training aid. The vapor profiles of complex materials such as decomposing human 6 remains [4, 5] and explosive materials [1] are known to change over time, yet few studies 7 have been performed to evaluate their vapor-time profiles. As part of the development of 8 alternative training aids, the vapor-time profile of the aids must be monitored to 9 determine its functional lifetime.…”