Frequently Asked Questions


The HOUND® CANNABIS BREATHALYZER is a Fast, Instrument-read, Technical (FIT) solution that makes it easy to measure recent cannabis use in breath and to determine on-site within minutes whether a breath sample is negative or non-negative for THC. The system includes a handheld used to perform the collection and a base station used to analyze the breath sample.

Hound Labs is currently contracting with companies to purchase the system. Interested companies are encouraged to connect with sales.

The automated solution makes it simple for both collectors and donors. A donor breathes into the mouthpiece. A single-use cartridge automatically captures a breath sample sufficient for both immediate on-site processing and lab confirmation if required. After the breath sample has been collected, the cartridge is removed and placed in the base station for analysis. Within minutes, the base station will indicate whether the breath sample is negative or non-negative for THC. If non-negative, the remaining portion of the sample can be analyzed at a lab to confirm the on-site results.

It detects cannabis in the breath, isolating recent use that corresponds with the workday. The system works by detecting THC molecules in breath where they remain present for just a few hours after smoking, making it a reliable means by which to specifically isolate recent cannabis use.1

A Hound® Cannabis Breath Test includes both sample collection and analysis. During collection, the donor breathes into the handheld for approximately two minutes. From the time the breath cartridge is inserted into the base station for analysis, the timeframe for receiving results is approximately 20 minutes. 

The system does not require manual calibration. It self-calibrates with each test to ensure consistent, instrument-read, accurate results.

The system is anticipated to perform optimally for several years and process thousands of tests during its lifespan. 

“Shy lung” occurs when a donor is unable to, or chooses not to, provide an adequate amount of breath to perform a breath alcohol test. Unlike a breath alcohol test where the donor must blow continuously into a handheld for at least six seconds or until enough breath is captured, the Hound® solution allows the donor to breathe normally and pause between breaths as needed. If too much time elapses between breaths, a warning message will appear on the system touchscreen instructing the donor to resume breathing to avoid invalidating the collection. When a sufficient sample has been collected, the system will automatically cease collection and notify the collector on the touchscreen. If a donor does not provide an adequate sample or pauses too long between breaths, the system will provide an error message and end the collection. 

The following educational content is available on the Hound Labs website: 


The solution is ultra-sensitive, measuring in parts per trillion. In contrast, alcohol breathalyzers measure in parts per thousand. This means the solution measures in units one billion times more sensitive than an alcohol breathalyzer.

The Hound® system is specifically designed to measure only THC, the principal psychoactive compound in cannabis. It does not detect inactive cannabis metabolites, or other cannabinoids that have a different molecular structure.

The technology detects THC in breath using an Enzyme-Linked Immunosorbent Assay (ELISA), an ultra-sensitive immunological test used to detect and quantify specific substances.

The test detects THC in breath for approximately three hours after smoking.

THC is detected in the breath after it has moved into the lungs from the bloodstream.2 Regardless of how an individual ingests THC, a breath sample may indicate a non-negative result if the donor has consumed THC at a high enough quantity.

No. The test is specific enough to isolate the detection of THC and avoid detection of other cannabinoids such as CBD, which is a distinct molecular compound from THC.

The Hound® test is designed to detect THC, the psychoactive compound in cannabis. The system will measure delta-9 THC and delta-8 THC in breath samples and indicate a non-negative result if the combined amounts detected exceed the cutoff level.


The Hound® breath test is the only cannabis test that can identify recent cannabis use, isolating use that occurs within a few hours of a test. Conventional cannabis tests can render non-negative results for use that occurs days, weeks, or even months before the test. While oral fluid, urine, and hair tests can be effective for other drugs and for zero-tolerance testing programs, a breath test provides objective information about cannabis use that corresponds with the workday. The solution allows companies to balance SAFETY + FAIRNESS™ by limiting positivity to a recent use detection window.

Industry best practices recommend screening and confirmation using the same testing methodology. However, employers could conduct a cannabis breath test in conjunction with a urine or oral fluid screen to isolate the timeframe of use. Breath testing provides employers with objective information about recent cannabis use that has occurred within a few hours of the test. 

Yes. The Hound® Solution automatically and simultaneously captures a breath sample within a tamper-evident cartridge sufficient for both immediate on-site processing and later lab confirmation if required. Technology within the cartridge retains the portion of the sample required for lab analysis using LC-MS (liquid chromatography–mass spectrometry). If company protocols require LC-MS confirmatory testing, the tamper-evident cartridge (which contains the confirmatory sample) can be shipped to the laboratory following conventional chain of custody protocols, such as those used for oral fluid and urine. 

Quest Diagnostics is the provider of laboratory services for confirmatory testing of non-negative breath sample results generated by the HOUND® CANNABIS BREATHALYZER.

Established practices for drug testing recommend employers send all samples that screen non-negative to an LC-MS (liquid chromatography–mass spectrometry) laboratory for confirmation. The anticipated turnaround for lab confirmation of non-negative results generated by the Hound® system is 3-5 days from receipt at the lab, which is standard turnaround time for confirmation of non-negative screening results for all sample types.

The Hound® solution can be used in multiple drug testing scenarios including: 

  • Pre-employment
  • Onboarding
  • Pre-access
  • Reasonable suspicion
  • Post-incident
  • Random
  • Return-to-duty

Employers are advised to review state laws to ensure their drug testing programs comply with all aspects of the law. 

Hound Labs is not aware of any state where its solution cannot be utilized. Prior to implementing any drug testing solution, Hound Labs strongly encourages customers to seek the advice of qualified counsel.