How do they do drug testing?

Tip #1. Drugs eventually show up in your body fluids and hair in one form or another. So, you'll be asked to "donate" a sample (specimen) of one of the two, which is submitted to a drug testing lab for chemical analysis.

• Because your hair grows slowly, certain drugs can be detected for longer periods historically, but typically only for heavy-duty and continuous use. Hair analysis is the least invasive, but might not reveal recent use.
• Blood analysis is the most accurate, but pricey, definitely invasive, and not allowed in the Federal drug testing program at this writing.
• Saliva and sweat analysis are accurate, but not yet popular methods at this writing.
• Urine analysis is less invasive than blood analysis, typically the least expensive, and can detect infrequent or recent single use.

For these reasons, urine analysis is the most common drug test, so a urine specimen is likely what you'll submit. It's also what we'll stick with when referring to your specimen. If the specimen-collection facility goes by the book, you'll start by replacing some or all of your street clothing with one of those hospital-type gowns that lets your backside stick out, to reduce the likelihood that you can smuggle something in to tamper with your specimen. Then an escort will steer you into a "dry room" that doesn't have much in it, to further prevent you from tampering with your specimen. In the absence of a dry room, it might be a restroom with the faucets turned off at the main valve and colored water in the toilets, also to prevent tampering. In either case, your escort might observe you or hover nearby while you urinate in the vial.

Then your specimen is off to a drug testing lab, where they'll typically test it for the drug itself or the substances (metabolites) produced by your body when it processes (metabolizes) the drug. If they follow the Federal drug testing guidelines, they'll perform an initial screening and then confirm the results with more sophisticated tests.

Under the Federal guidelines, drug testing has two cutoff levels for positive detection. That is, labs that follow the guidelines consider drug testing to be negative if detection is below either cutoff level. In the case of urine analysis, drug testing cutoff levels are measured in nanograms per milliliter (ng/ml). For example, an initial screening for marijuana must show at least 50 ng/ml, and then confirmatory tests must prove at least 15 ng/ml. If the initial screening doesn't show at least at least 50 ng/ml, then it's considered to be negative and the confirmatory tests aren't performed.

But, to put it into perspective, a gram is only thirty-five thousandths (0.035) of an ounce, and a nanogram is a mere one-billionth (0.000000001 or 10^-9) of a gram. So, we're talking about microscopic particles measurable in only a few drops of urine. Molecules. Consequently, even infrequent, recreational drug use might cause employees to fail drug testing.

Can I beat a drug test and pass?

For example, there is speculation that loading up on water before a urine drug test might dilute drugs and metabolites just enough, to put them below the cutoff levels. But, lots of water makes your urine look pale. It's a healthy sign that you're well-hydrated, but also a waving flag that you might have tried to "flush." NORML, a group working to reform marijuana laws, suggests that you might be able to beat watery-urine detection "visually" if you also take vitamin B-2, which tints your urine yellow.

See the sidebar for more of NORML's tips, but don't get too excited about them just yet. For one thing, labs have the option to conduct specimen-validity tests at their discretion. For another, on August 21, 2001, SAMHSA introduced a proposal to standardize and require urine validity tests across the board, to better detect specimen adulteration. Regardless of its color, labs can detect abnormal pH and creatinine levels in urine, and measure its specific gravity. So, even if you don't get busted for cheating per se, your persecutors might ask you to take the drug test again, on shorter notice and with closer observation.

Another myth is about claiming to be a "passive" user, like by incidentally inhaling ambient pot smoke at a rock concert. You can try using that excuse, but if you're a regular pot smoker, it likely won't fly. Your level will probably be above the cutoffs and far above that of the passive smoker, which, at only about 5 ng/ml or so, is well below the cutoffs. The same goes for passive absorption, like from maybe handling a dollar bill that was unknowingly rolled into a "straw" to snort coke. But, nice try.

It's true that poppy-seed ingestion can cause false positives for opiates a few hours later in urine tests. But labs claim that hair analysis can distinguish between opiate abuse and poppy-seed ingestion. Additionally, the Feds are familiar with urine-adulteration tricks. Consequently, the Feds upped the ng/ml detection level beyond that of "normal" poppy-seed ingestion, but still within the range of abuse. Normal ingestion is considered to be like two poppy-seed muffins in a day, tops.