Did You Know Drug Detection Times Depend on the Test You Order?
You finally found a drug test that covers all of the substances that you want to test your employees for. It seemed like a great choice. It was a good price, covered what you needed, and had fast turnaround times. You checked all your boxes, so what could go wrong?
Little did you know at the time that you ordered the wrong type of test and that you hired someone who introduced significant workplace safety risks as a result. Keep reading to find out how to avoid this scenario.
Listen to article
Table of Contents
What Are Drug Screening Detection Times?
Drug test detection times are exactly what they sound like—how long after use a drug test can still detect a substance in someone's system. It's simple to define, but hard to list exact timeframes for a few reasons. Detection times depend on the drug, how often it's used, how much of it is used, the person's metabolism, and the type of sample you collect.
How Do Drug Detection Times Work?
Detection windows all work in the same way, although the exact window is hard to define. Here's how it works.
-
Someone uses a drug. It enters their bloodstream within minutes to hours, but it depends on the type of drug and how it was used (smoked, swallowed, injected, etc.).
-
The body starts breaking it down. This creates drug metabolites. Some tests detect the substance itself, while others detect its metabolites.
-
Trace amounts show up in different samples at different times. This is one of the most important parts of choosing a drug test. For example, saliva picks up the drug almost right away, while hair can take a week or longer to detect the same substance.
-
The test then looks for levels above a set cutoff. If the amount detected in the sample is greater than the cutoff, then a positive result is reported.
-
Levels drop until the detection window closes. How fast that happens depends on many factors, including the individual and the type of test chosen.
Simply put, detection times work in the same way, but timeframes can vary according to many other factors. For example, saliva might detect that someone is currently under the influence, but hair testing would miss the same substances because not enough time has passed for the drug or its metabolites to make their way into the hair follicles. So the same person could test for the same substance at the same time, and get a positive test result for saliva while getting a negative test result for hair.
Factors That Influence Drug Detection Times
Biological Specimens
Different types of samples, such as urine, saliva, and hair, offer distinct detection windows.
-
Urine testing typically detects drug metabolites over several days
-
Saliva testing focuses on recent use within hours to a couple of days
-
Hair testing covers about 5 to 90 days back
Individual Person
A person's pattern of drug use and how their body processes the drug can influence detection windows. Some factors:
-
Metabolism
-
Frequency of use
-
Amount used
-
Type of drug used
-
Hydration levels
Type of Drug Test Used
Urine drug test detection times are much shorter than hair drug test detection times. Similarly, saliva detection times are shorter than urine.
-
Urine test: up to a week back
-
Saliva test: up to 48 hours back
-
Hair test: about 5 days to 90 days back
Accuracy and Reliability of Detection Windows
It is important for employers to understand that detection windows are estimates, not guarantees. Variability between individuals and testing types means that results must always be used carefully.
Confirmatory testing using advanced methods such as LC-MS/MS ensures the highest level of accuracy and reliability.
Choosing the Right Test
Finding the right test for your company depends on your goals and your risk profile.
-
Urine testing is commonly used for pre-employment screening or random drug testing
-
Saliva or urine testing is often used for post-accident or reasonable suspicion testing
-
Hair testing has a longer lookback at drug history, which is sometimes used for leadership or roles that require a high level of trust
Some industries regulate exactly which test you can use, when you can use it, and what situation you can use it in. It's important to stay up to date on federal and state regulations for your industry to ensure you're not violating any of these rules.
Common Mistakes Employers Make
Some of the common mistakes that we see employers make include:
-
Employers look only at the test price and the substances included. One of the biggest mistakes an employer can make is assuming the detection windows are all the same.
-
Not considering the specific risks associated with their industry. For example, using a basic panel in an industry with high prescription drug abuse may leave gaps in detection.
-
Waiting too long after an accident happens to drug test. The detection window starts closing fast, especially for immediate use tests like saliva. Too long a delay can cost you an answer.
-
Assuming a bigger panel looks further back. A 10 panel checks for more drugs than a 5 panel, but it doesn't have a longer detection window. Urine drug screen detection times all work the same way regardless of how many substances are tested.
How Detection Times Affect Workplace Safety
Testing methods that detect recent use can help prevent impaired employees from performing safety-sensitive jobs. Longer detection windows can identify patterns of substance use that may require intervention. However, no single testing method is good for all scenarios.
After a near miss in the warehouse with a forklift, a saliva test can show quickly whether the employee used recently. When you're hiring someone to drive a company vehicle, a longer window can show if drug use is a habit. Ordering the wrong test, or collecting it too late, can clear someone who shouldn't be cleared.
Frequently Asked Questions
How long do drugs stay in your system for a drug test?
Drug detection times vary depending on many of the factors covered throughout this blog article. For an idea of detection windows based on test type, take a look at our Type of Drug Test Used section above.
Which drug test detects recent use best?
Saliva tests are the most effective for detecting recent drug use. Saliva testing is commonly used in workplace settings because it is non-invasive, provides quick results, and can help identify recent drug use.
Can drug test detection times vary by person?
Yes, detection times can vary between individuals. This variability is why employers should rely on laboratory-confirmed results rather than assumptions. For more information about how drug detection times can vary by individual, see the Individual Person section above.
