Workday detection matters

How long is marijuana detectable in a drug test? The short answer is – it depends. Several drug test types exist today, and they all detect the usage of marijuana (also known as cannabis or THC) over different timeframes. But in the era of cannabis legalization, knowing when – not just if – someone used cannabis is more important than ever. And to really determine that precise period of recent use, you need a test with the shortest cannabis detection window.



Many marijuana test types can provide positive results for days, weeks, or months after use. Why? Because they don’t isolate recent use to determine whether an employee’s cannabis use may impact workday performance.

“We have a lot of good folks that maybe partake on the weekend, but Monday through Friday at work they don’t.”

Motor Vehicle Manufacturer

With the shortest cannabis detection window in the drug testing industry, the HOUND® CANNABIS BREATHALYZER is the first and only ultra-sensitive breath test that helps detect and deter marijuana use correlating to an employee’s workday.


In cannabis testing, a window of detection indicates how long a test will detect THC in a biological sample, such as oral fluid, urine, hair, or breath. The detection window for THC (the principal psychoactive compound found in cannabis) varies depending on which type of drug test is performed (see Figure 1). Cutoff levels bookend the upper and lower bounds of drug detection. Drug levels below the cutoff will appear at both the front and back end of the detection window and are associated with a negative test result. Within the detection window, the presence of a drug above the cutoff level will trigger a non-negative or positive result.

The window of detection is dependent on a variety of factors, including frequency of use. For example, occasional users of cannabis may have THC in their system for only a few days after use, whereas frequent users may show traces of the drug in a urine test for up to a month.1

1 Quest Diagnostics

Hound Labs Cannabis Detection Times


YES - The detection window of a cannabis breath test only extends for 2-3 hours after use,2 making breath the only test type that can isolate cannabis use surrounding the workday. This is an important distinction because THC metabolites that are detectable in other test types like urine and hair may remain in a person’s system for weeks or even months after use, but the safety-impacting effects of the drug have likely long subsided.

This precise detection window of breath testing helps employers enforce policies that prohibit use immediately before or during work but do not penalize cannabis use outside of work as outlined in the employer’s policy.
2 Clinical Chemistry


Growing access to legal cannabis is leading to increases in workday use. In an era when most adults in the U.S. have access to legal cannabis, safety still matters. Employees do not want to sacrifice safety because the legal status of cannabis has changed.  Most people do not care what their coworkers choose to do after work hours, they just do not want their coworkers to use cannabis during the day and create safety concerns for others.


42% of employees in a safety-sensitive position have observed workplace cannabis use


53% of employers who dropped cannabis testing experienced an increase in safety incidents


75% of employees think recreational cannabis use during work affects performance

As much as safety matters to employees, so does fairness. Growing acceptance and rapid legalization of cannabis have created unintended consequences, especially when used during an employee’s personal time.

“Too many times in my career have I seen valuable experienced employees be reluctantly let go because of outdated beliefs that do not fit our new culture. This product would truly help.”

Manufacturing Industry Employer

Previously, employers faced challenges with workplace safety and equitable decisions regarding cannabis use. Now, with the HOUND® CANNABIS BREATHALYZER, employers have an option that provides objective data to balance workplace safety with employee fairness and privacy.


Cannabis legalization is increasing access, use, and drug test positivity – making it harder for employers to maintain safe workplaces, hire qualified applicants, and retain valuable employees. Their challenge? Legacy tests with long detection windows that do not provide relevant information about an employee’s workday.

  • Cannabis can be detected in oral fluid immediately after use and for as long as “32 hours with the occasional users and 72 hours with the frequent users.”3
  • The detection window for THC metabolites in urine can last as long as 30 days.4
  • Based on the length of hair being tested, THC metabolites are detectable starting about one week after the drug’s ingestion and for as long as three months.5

3 Department of Health and Human Services
4 Quest Diagnostics
5 Quest Diagnostics

Let’s take a closer look at each type of cannabis test to better understand how detection windows are determined.

Cannabis detection Times

Up to 3 Hours
Up to 3 Months
hound labs clock grey 900px _opt
Oral Fluid
Up to 72 Hours
Up to 1 Month

THC, the psychoactive compound in cannabis, is detected in breath, oral fluid, and blood. THC-COOH, a metabolite of THC, is detected in urine and hair.


Breath Testing

A University of California, San Francisco (UCSF) study confirms that THC is detectable in breath for up to three hours after smoking cannabis. After that, THC reduces to virtually undetectable levels. The detection window of a cannabis breath test aligns with this research, providing the shortest detection window of 2-3 hours after use.This is an important distinction from legacy tests using an oral fluid, urine, or hair sample. THC and its metabolites may remain in these sample types for days, weeks or even months after use, presenting the risk for a positive drug test long after the safety-impacting effects of the drug have subsided. Only the detection window of breath testing corresponds to the use of cannabis surrounding the workday.



Oral Fluid Testing

Cannabis can be detected in oral fluid immediately after use and for as long as “32 hours with the occasional users and 72 hours with the frequent users.”8 THC is present in oral fluid primarily through contaminating deposits that linger in the mouth after use of the drug. When someone smokes or consumes an edible containing cannabis (such as gummies or a brownie), THC is sequestered in the oral mucosa or tissue in the mouth and released into the saliva. Even though an oral fluid cannabis test has a shorter detection window than urine, it is still much longer than a breath test.
8 Department of Health and Human Services


Urine Testing

The detection window for THC metabolites in urine begins within a few hours after use and can last as long as 30 days. Urine is the most common cannabis testing sample, in part, because it’s been around the longest and is required by federal agencies and contractors. This timeframe is somewhat dependent on factors such as the donor’s frequency of use and testing cutoff levels.

The detection window for urine is even longer than for oral fluid because THC is metabolized into various inactive metabolites before being excreted in urine.9  Rather than THC itself, these metabolites are the target of urine testing.
9 Quest Diagnostics



Hair testing is typically used to detect a long-term pattern of repetitive use. Based on the length of hair analyzed, THC metabolites can be detected starting about one week after the drug’s ingestion and for as long as three months. Hair tests generally have the longest detection window – up to 90 days after cannabis use.

Similar to urine tests, hair tests don’t test for THC but instead test for the non-psychoactive THC metabolite, THC-COOH. Starting from the scalp, every centimeter of hair length equates to an approximate one-month detection window.10
10 Human Cannabinoid Pharmacokinetics, Chem Biodivers, Aug 2007


Deter Workplace Cannabis Use One Breath at a Time

The first breath test to isolate recent use