VOC (Volatile Organic Compound)
Definition
Carbon-containing compounds that evaporate readily at ambient temperatures. Decomposing human tissue produces a complex, changing VOC mixture that HRD dogs are trained to detect.
- Definition scope
- Carbon-containing compounds that evaporate at ambient temperature
- Source in casework
- Decomposing human tissue
- Detected by
- Human remains detection (HRD) dogs
- Mixture behaviour
- Composition changes over the decomposition timeline
Common questions
Why can an HRD dog detect remains a piece of equipment struggles to find?+
Canine olfaction can detect the VOC mixture at concentrations well below the sensitivity of many portable chemical detectors, and dogs generalise across the shifting blend of compounds released at different decomposition stages rather than needing to be tuned to a specific target chemical.
Does the VOC profile of decomposition stay the same across a body's decay?+
No. The specific compounds and their relative proportions change as decomposition moves from the fresh through bloat, active decay, and skeletal stages, which is why HRD dog training uses scent material representing multiple stages rather than a single reference odour.
Related terms
- HRD Dog
- Human Remains Detection dog: a dog trained to detect and alert on the volatile organic compound signature of decomposing human tissue. Also...
- Passive Alert
- A trained response in which the dog sits, lies down, or freezes at the scent source without digging or pawing. Preferred in...
- Scent Cone
- The plume of airborne VOC molecules that diffuses upward and downwind from a buried source. A dog working downwind of a buried...
- Search Pattern
- The systematic geometric route walked by a dog handler to ensure uniform coverage of the search area. Standard patterns include the ladder...
- Tile Probe
- A solid steel rod used to probe suspect ground by hand pressure, detecting resistance changes in disturbed soil and releasing sub-surface gases...