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TADDs® Explained || Precision Explosives
- Yana Allport
- Jun 5
- 8 min read
Hi there, science lovers!
The Training Aid Delivery Device - or TADD® - has quietly become one of the most important pieces of hardware in modern detection training. It's also one of the easiest tools to misunderstand… so let's break it down!
What Is a TADD®?
The TADD® is a containment and odor delivery system developed by SciK9®. It was originally built for the U.S. Army and designed by canine trainers and scientists working a problem that has plagued detection programs for decades; how do you safely contain a potentially dangerous training aid while still letting the target odor reach the dog's nose?
The answer is elegantly simple. At its core, the TADD® is a jar with a specialized membrane that lets vapor pass freely while physically blocking liquids, particulates, oils, and other material from escaping. One device handles containment as well as odor delivery; replacing the old "scent bag plus mason jar" routine with a single device.
Three components make it work:
The Jar: Glass or plastic, four sizes (Small, Medium, Large, Extra-Large). The transparent jars allow you to monitor your aid for decomposition or crystallization without breaking the seal!
The Odor Permeable Membrane Assembly: A gas-tight chemical-resistant gasket (Viton), a hydrophobic and oleophobic PTFE membrane, and a custom polypropylene membrane holder that has a safety grid to keep the membrane from being punctured.
The Gas-Tight Lid: Polypropylene, chemical resistant, fully hermetic when closed. Shuts down out-gassing during storage and transport.
Every TADD® component is NASA outgassing compliant (ASTM E595). That means that the
device itself releases extremely low levels of volatile organic compounds, so the background
odor is minimal.
TADD® Uses
TADD®s are used across a wide range of K9 disciplines and industries, including:
- Law Enforcement (LE): Explosives, narcotics
- Search and Rescue / Human Remains Detection (SAR/HRD): Human remains, blood, bone
- Conservation: Scat, bedding, fur
- Pest Detection: Bed bugs, scat, eggs, live ants
- Biomedical: Clinical samples, COVID-19 patient samples, biopsy tissue
- Medical Detection: Diabetes, seizure, cancer, allergen
At Precision Explosives, we partner with SciK9® to offer TADD®s pre-charged with POCR media - explosives, narcotics, and bed bug aids prepared in a clean environment, sealed, and ready to deploy. PE prepares all aids in a clean environment with tamper-evident seals to support chain of custody and program documentation.
What the TADD® Does Well
1. Preserves Odor Integrity
Traditional containment methods (mason jars, sniffer tins, zip-lock bags) introduce background odors from their own materials and allow environmental contamination to degrade the training aid over time. The TADD® eliminates this by combining the primary containment with odor delivery in a single, low-background device. The sealed system protects training aids from dog saliva, dirt, dust, and human scent between training sessions - maintaining a cleaner, more consistent odor profile across the life of the aid!
2. Reduces Handler Contamination Risk
Because the training aid never needs to be removed from the TADD® during normal training operations, handlers have far less direct contact with the substance itself, preventing cross-contamination as well as ensuring safety. For hazardous materials (explosives, narcotics, biological samples, human remains, etc.) this reduces the risk of accidental exposure or inadvertent contamination of the training environment. The gas-tight lid shuts down all odor emission during transport and storage, further reducing environmental scent spread.
3. Extends Training Aid Shelf Life
Training aids degrade with repeated handling and with exposure to different environmental
conditions. Because the TADD® is loaded once and then sealed, training aids remain in
cleaner, more controlled conditions for longer. Plus, the transparent jars allow for visual
inspection without opening!
The TADD® components have a ten-year shelf life when stored at room temperature.
4. Provides Operational Versatility
The TADD® has been deployed in an exceptionally wide range of environments: buried in sand, soil, and rubble piles; submerged in lakes, rivers, and toilet tanks; concealed in vehicles, warehouses, luggage, cargo, buildings, and open areas. Optional accessories can extend this versatility even further:
Odor Restriction Caps allow handlers to control the surface area of the membrane opening - from a fully open ~2,000mm² to as small as 2mm² - enabling progressive odor threshold training without changing the quantity of training aid.
Hook Magnets and Disc Magnets paired with Stainless Steel Scent Cans extend placement options to elevated or hard-to-reach hide locations.
Whatman Filter Paper allows target odor to be transferred to a more concealable medium for locations where the TADD® itself is too large.
Metalized Odor Barrier Bags serve as secondary containment for highly odorous aids.
5. Supports Hazmat Safety and Chain of Custody
For agencies handling regulated substances, the TADD®'s sealed design supports chain of custody documentation and reduces the number of times a hazardous substance needs to be physically handled. Precision Explosives provides pre-loaded TADD®s with tamper-evident seals for this exact purpose. TADD®s also safely contains liquids, oils, solids, small particulates, and certain hazmat materials, all while still permitting odor transmission through the membrane.
How People Misuse TADDs®
A TADD® can do a lot, but it cannot overcome bad handling. The hardware is excellent - but the dog only benefits if the human using it understands what's actually happening. Here are the misuses we see most often.
1. Opening the Membrane Holder Instead of the Cap
This is the most frequently reported handler error. The TADD® has two removable components that can look similar: the white gas-tight cap (which should be removed for training) and the black membrane holder (which should never be removed during training). Handlers who accidentally unscrew the membrane holder instead of the cap have effectively broken the seal on their training aid, potentially contaminating the environment or compromising the training aid itself.
Always remove only the white cap.
Always hold the black membrane holder in place.
2. Using Incompatible Training Aids
Not every substance belongs in a TADD® in its current form. Known incompatibilities include:
Nosework essential oils in liquid form (Birch, Anise, Clove): These oils are highly reactive with the TADD®'s Viton gaskets, causing them to swell and deform, which can lead to leaks.
Note: The TADD® is fully compatible with the NACSW cotton swab absorption method for these same oils; it is only the bulk liquid form that is problematic.
Bulk peroxide-based explosives (TATP, HMTD): The threaded jar neck presents a potential detonation risk if particulate becomes entrapped, and the TADD® jars are not made from electrostatic discharge (ESD) plastic as required for these materials.
100% acetone and similarly aggressive solvents: Acetone causes rapid gasket warping and destruction.
Accelerants (arson training aids) and nitromethane: These require modified gaskets before the TADD® can be used safely. Contact SciK9® before use.
3. Reloading the TADD®
The TADD® is designed to be loaded once. Once the membrane holder is torqued down onto the jar and gasket, the three components (jar, gasket, membrane holder) cannot be reliably reassembled under the same torque, which causes the membrane to pucker and compromises the device's barrier properties. Handlers who attempt to reload a TADD® after disposal or between different training aids risk an unsealed device that can leak, contaminate the environment, or give the dog an inconsistent odor picture.
4. Using Only TADD®s (No Containment Variation)
Every container has its own scent, and the TADD® is no exception. A dog that is trained exclusively with a single type of containment will learn to associate the container's background odor (however minimal) with the target odor picture. When the dog is ever asked to detect the same substance in a different type of containment (a tin can, a bag, or no containment at all), performance can suffer. Vary your training sessions: different training aids, different containers, different odor concentrations; this enhances your dog’s capability to generalize to the wide variety of threat presentations they’ll encounter in the real world!
5. Skipping Blank Controls
A common training shortcut is running hides without including blank, empty TADD®s in the search area. Without blank controls, the dog cannot learn to differentiate between the odor of the container (no matter how small) and the odor they are being trained to detect. SciK9® recommends including blank TADD®s in every training session. The dog should encounter empty TADD®s frequently enough that they become part of the background noise, not the signal.
6. Smothering the Membrane
During field hides, particularly in mud or soft soil, the membrane can become physically smothered by the substrate, blocking odor from escaping. When burying or concealing a TADD®, handlers should create an air gap between the membrane and the surrounding environment to ensure odor has a path out. Similarly, the membrane may "wet out" (pores clogged from long-term liquid exposure under pressure), thus the TADD® should be allowed to dry thoroughly before reuse.
7. Cooking Your Plastic TADD®s
Plastic TADD® jars can deform at temperatures above 150°F (65°C), which can be reached inside a vehicle during hot weather. Handlers who leave plastic TADD®s in patrol cars during summer months may return to find warped or compromised jars. Glass TADD®s are more temperature-stable, though even glass TADD®s should be transitioned slowly between temperature extremes (e.g., from freezer to ambient) to prevent pressure-related membrane stress.
8. Puncturing the TADD® membrane
You’re paying for the fancy membrane - don’t puncture it! Just because you can’t see through it doesn’t mean odor isn’t getting through. The membrane is what keeps the source free of contaminants while still allowing the odor you’re training your dog on to pass.
9. Forgetting to Discard the Blue Paper When Loading the TADD®
TADD®s from SciK9® come with a creased blue piece of parchment paper between the jar and membrane gasket. This paper should be discarded prior to loading and sealing the TADD with your training aid as it will severely inhibit training aid odor emission.
Lower Odor Concentrations with Restriction Caps
As the dog develops confidence and proficiency, the Odor Restriction Caps can be used to gradually reduce the amount of odor available from the TADD®. Moving from the fully open membrane (~2,000mm²) down through progressively smaller openings (500mm², 200mm², 20mm², 2mm²) trains the dog to work at lower odor concentrations, approximating real-world operational scenarios where target substances may be in trace amounts. This also reduces the risk of a dog becoming dependent on a high-odor presentation from the device.
For a deeper dive on the importance of training for trace odor, see our post on training detection dogs to find small amounts of odor.
TADD®s and Fentanyl
Fentanyl, fentanyl analogues, and now cychlorphine… TADD®s are the only containment system on the market capable of safely delivering the drug odor. If you are working a dog on fentanyl, let us know - we will make sure you get the appropriately sized membrane for the job to keep both you and your K9 safe.
Proofing off of TADD®s
If you train with membrane devices, you need clean blanks. You need the dog to work problems where the device is present without target odor. You need to vary placements, hide contexts, search order, and problem design so the dog is not learning a shortcut. You also need to be careful that “blank” truly means blank. A blank that has lived next to loaded aids, ridden in the same bag, or been handled carelessly is not a blank anymore.
One of the most important (and most neglected) aspects of working with TADD®s is proofing the dog off the device itself. A dog that is "container dependent" will struggle in operational environments where the substance is not in a TADD®. Conversely, a dog that is properly proofed will seek and respond only to target odor regardless of its packaging.
In another proofing exercise, place empty TADD®s near live hides of another containment type, or place live-loaded TADD®s in areas with strong environmental distractors. The dog should work through the presence of the TADD® container without false alerting, and should respond to target odor in non-TADD® containment without hesitation.
A Note on Documentation and Chain of Custody
For law enforcement and government agencies, the TADD®'s sealed design supports formal training documentation and chain of custody logs. Precision Explosives provides pre-charged TADD®s with tamper-evident seals to assist with this process. Agencies are encouraged to log TADD® serial numbers or batch information, the date the TADD® was loaded, the handler and dog assigned to the aid, and each training session in which the aid was deployed. Maintaining this documentation not only supports legal defensibility but also enables trainers to track training aid performance and shelf life over time.
TADD®s Bottom Line
The TADD® is one of the most scientifically rigorous training aid containment and delivery systems available to detection K9 programs today.
When used correctly, the TADD® preserves odor integrity, protects both handlers and their dogs, reduces cross-contamination, and supports training in nearly any operational environment.
The path to getting the most out of the TADD® is the same as the path to getting the most out of any detection training tool: introduce it systematically, proof against it, and never let the container become the cue.
