On-site drug testing has become a standard practice across many industries. The testing itself, although some employees may perceive it as intrusive, is conducted to boost workplace safety. And by safety, we’re talking about both employee-relationship and work accident-related issues.
So, if your employer announced that a drug test will be happening in the near future, we should talk about how the test will be conducted, which drugs will be tested for, and ultimately, what to expect when the results come in.
Before we begin, please note that this article provides general information and does not replace legal advice.
What is On-Site Drug Testing? As the name suggests, on-site, aka employment drug testing, is the process of screening employees for the use of drugs, and in some cases, alcohol. Mostly, the main industries that conduct these tests regularly involve a significant amount of responsibility, ranging from operating heavy machinery to performing high-stress jobs.
So, let’s touch on the industries with the highest testing standards, and let’s see which drugs are most commonly screened for.
Which industries have the highest testing standards?
Before we dive into the specific industries and their testing standards, it’s important to note that laws regulate drug testing differently in most states (especially in the United States). There are general rules for how the testing must be performed, but to be sure, it’s always best practice to double-check with your local labor laws.
Here’s a list of industries and sectors that test their employees regularly ( mostly annually, post-incident, or under reasonable suspicion ):
Construction, manufacturing, and warehousing – as we mentioned, wherever heavy machinery is operated, drug testing is performed as a measure of preventing injury Mining, energy, and utility – these are sectors with highly hazardous environments that have a low tolerance for on-site intoxication Transportation – the DOT drug test is heavily regulated, both during employment and pre-employment Healthcare – employees who have access to controlled substances are tested to prevent and discover on-site abuse Aviation – similar to transportation, both flying (pilots and crew) and ground control are tested due to the high-responsibility nature of the profession Federal roles and public safety – again, due to high stress and responsibilities, law enforcement, firefighters, military, and federal agents are eligible for drug testing as well Which drugs are most commonly screened for? The drug panel used for screening may vary across different sectors. The federal SAMHSA test is a 5-panel test. However, there is a common, extended 7-panel test designed to discover the use of the seven most commonly used drugs in the US:
THC (cannabis, marijuana) COC (cocaine and crack cocaine) OPI (opiates, including heroin, morphine, and codeine) AMP (amphetamines) MET (metamphetamines) BZO (benzodiazepines, like diazepam and alprazolam) MDMA (Ectasy) Some sectors and industries do a smaller, 5-panel test that doesn’t include MDMA and methamphetamines. Some employers may also conduct separate alcohol breath testing, particularly in safety-sensitive roles. Most likely, the employer will announce this in advance. But, if you’re unsure, it’s best to check the local labor laws.
How Is Employment Drug Testing Conducted? The most common sample used in on-site drug testing is urine. A certified agency will send a trained sample collector to collect specimens. A Medical Review Officer (MRO) later reviews and verifies any positive results. If the screening results are positive, the sample will be sent to a laboratory for confirmatory testing.
Screening test Screening tests are done at a higher cutoff level. This represents a threshold that detects the presence of drugs or drug metabolites in the system. It’s expressed in nanograms per milliliter (ng/ml )of the sample provided.
For example, the standard cutoff level for a screening test for THC is 50 ng/ml , which is enough to detect both recent and prolonged use.
Confirmatory test If the screening test turns out to be positive, the sample is sent to a laboratory for confirmatory testing. This type of test is done using chromatography (GC/MS or LC-MS/MS), and it’s much more strict when it comes to the detection threshold.
For example, the standard cutoff level for THC confirmatory tests is 15 ng/ml . A confirmatory test is also designed to eliminate accidental exposure, like secondhand smoke.
What to Expect When The Results Come In
Now, if the test comes back negative, the process of on-site drug testing ends then and there. But if the screening and confirmatory tests come back positive, depending on the local labor laws, your employer will present you with one of the following scenarios:
Referral to a rehab program Temporary suspension , especially if the job includes working in high-risk or hazardous conditions Disciplinary action , previously agreed upon in the case of a positive drug test result *Outcomes depend on company policy, labor laws, and union agreements.
False positives While on-site drug testing is designed to be an exact method to detect drug use, there are nuances to it.
For example, certain medications prescribed for specific medical conditions can affect the initial screening test. That’s why it’s crucial to convey this to the MRO before you take the test. These include:
Certain cold medications (pseudoephedrine and ephedrine) Prescription ADHD medications (amphetamines) Antidepressants (may give false positives for benzodiazepines and amphetamines) Sleep and anxiety medications (benzodiazepines) Strong pain medications (opiates or opioids) Hemp-based pain relievers (THC) Another source of false positive results, although rare, is certain foods or supplements. Frequent poppy-seed consumption may trigger a false positive for opiates on the screening test. Additionally, hemp-based foods (oils, seeds, hemp protein) can trigger a false positive on a THC test.
What matters is – if you suspect that some of these foods or medications may trigger a false positive, make sure to declare that to MRO on the day of the test. Ultimately, the confirmatory test is designed to rule out false positives .
In Conclusion All in all, on-site drug testing is pretty straightforward. The most commonly used sample, urine, is collected on the day of the screening test. If the test comes back positive, a confirmatory test is conducted at a certified laboratory.
To avoid confusion, make sure to convey to the MRO if you’re taking any medication that might interfere with the test results.
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