Frequently Asked Questions


The HOUND® CANNABIS BREATHALYZER – available in Collect + Send and On-Demand models – is the first breath test designed for the era of legalization by limiting cannabis detection to the workday. Both ultra-sensitive systems specifically target active THC, the psychoactive compound of cannabis, and isolate detection to use that has occurred within approximately three hours of the test. This novel technology standardizes and automates the collection process, giving employers an objective result to help maintain safety and promote the equitable treatment of their workforce.

Legalization is changing the landscape of workplace cannabis testing. The HOUND® CANNABIS BREATHALYZER gives employers accurate and objective data to drive informed business decisions, helping balance workplace safety with employee fairness and privacy. With two models, Hound Labs can provide solutions for a wide range of use cases. Customers who do not require on-site results are ordering the Collect + Send model. Customers interested in on-location results within minutes of the collection are pre-ordering the On-Demand system.

Both systems utilize the same proprietary breath collection science and novel technology developed to automate and standardize breath collection. The main difference between the two is how test results are processed. Collect + Send results are processed at a Hound Labs partner laboratory using ultra-sensitive Liquid Chromatography Mass Spectrometry (LC-MS) testing. Screening results for the On-Demand system (in development) will be available on-site within minutes of the collection. Positive screens will be sent to a partner lab for confirmation.

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


The donor breathes into a disposable mouthpiece attached to a handheld cartridge. The single-use cartridge automatically captures a breath sample needed for testing. Employers using the Collect + Send model will ship the cartridge to a partner lab for processing. Employers using the On-Demand model will insert the cartridge into a smart base station for processing on-location.

The product is designed to be intuitive and easy to use. The testing process is automated, and the smart base station provides simple touchscreen instructions to guide both donors and collectors through the collection process. For training on how to use the system, collectors can access our Learning Management System at no additional cost. A Certificate of Completion will be issued once training is completed.

The donor breathes into the collection system for approximately 2-3 minutes.

Best practice guidance, as aligned with the product insert, is to maintain a temperature range between 15-30 degrees Celsius (59-86 degrees Fahrenheit).

Both models support automated, on-location breath collections. The intuitive design facilitates a simple collection process and helps reduce human error by automatically ending the breath collection once a sufficient sample size has been captured. This automation ensures donors provide a standardized amount of breath each time – optimizing the validity of results, whether processed at the lab or on location. Hound Labs is also actively working to build a nationwide network of collection site partners. If employers prefer, they may send donors to an enabled collection site, or arrange for an on-site collection event facilitated by a third-party collector at their employee facility.

Both Hound® solutions integrate seamlessly with our proprietary software, Hound Labs Retriever™ results portal. The Retriever™ online portal makes it easy to track and manage test results. During sample collection, the smart base station provides real-time information to the Retriever™ portal and populates a customer dashboard showing the status of each collection. During sample analysis, Retriever™ integrates directly with partner labs to update the dashboard with test results.

Customers with Collect + Send use Retriever™ to view the status of each sample sent to the lab, receiving updates on the date and time of sample collection, arrival at lab, and result processing completion. Customers with On-Demand can use the smart base station to process samples on-site and view screening results within minutes of collection. Samples with a non-negative result can be sent to a partner lab for confirmatory testing. Both lab-based and on-site results will be available for tracking and management through Retriever™.

The anticipated lab turnaround time follows the industry standard of 24 hours from receipt at the lab for screening results and up to 96 hours from receipt at the lab for results requiring confirmatory testing. This excludes weekends and holidays. When available, results can be securely accessed through the HOUND LABS RETRIEVER™ database by those users with access permissions.


The test detects THC in breath for approximately two to three hours after smoking. A clinical study from the University of California – San Francisco (UCSF) confirmed that THC is detectable in breath for up to three hours after smoking marijuana. Beyond three hours, THC levels drop to virtually undetectable levels. These results are published in a peer-reviewed study in Clinical Chemistry.

Yes. Regardless of how an individual ingests THC, a breath sample may indicate a non-negative result if the donor has recently 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 test will quantify delta-9 THC and delta-8 THC in breath samples and provide a non-negative result if the combined amounts of both delta-9 and delta-8 THC exceed the designated cutoff level.

The HOUND® CANNABIS BREATHALYZER is designed to meet standards set by lab instrumentation with tight tolerances and consistent, accurate results. The Collect + Send model utilizes laboratory processing and matches the accuracy of any test using LC-MS analysis and instrumentation. The On-Demand model utilizes a highly-sensitive lateral flow immunoassay to produce a screening result on-site within minutes of collection. Non-negative screening results from the On-Demand test can be sent to a lab for confirmatory testing. Both models detect THC molecules in breath in parts per trillion (shown in pg/mL), with ultra-sensitivity needed to accurately detect recent cannabis use. Testing is performed at SAMHSA-certified lab(s) and follows standard chain of custody (CCF) procedures.

The Hound® breath test specifically targets active THC, the principal psychoactive compound in cannabis. The test is specific enough to isolate detection of THC molecules without interference, avoiding detection of inactive cannabis metabolites and other cannabinoids or drugs that are distinct molecular compounds from THC.

A cutoff level is the minimum quantity of a drug analyte needed for a test result to be rendered non-negative. The screening and confirmation cutoff level of the HOUND® CANNABIS BREATHALYZER is 20 pg/mL.


The Hound® breath test is the first 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 limits positivity to a recent use detection window that corresponds with the workday.

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. 

‘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 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 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.