What is a Confirmatory Drug Test?
A confirmatory drug test is sometimes necessary when the initial test comes back with a positive result. Here is what you need to know about a confirmatory drug test
Having to go through a drug test is stressful enough in any circumstances. But what happens if you test positive? Your employer may require a “confirmatory drug test.” They might not even tell you it’s being done—just the result, once it’s over. What is a confirmatory drug test? When and why is it necessary, and how does it work? What does it mean for you? Here’s what you need to know.
What Is Confirmatory Testing?
A confirmatory drug test is sometimes necessary when the initial test comes back with a positive result. The problem is, on a low level test, coming back positive doesn’t necessarily mean there are drugs in your system. There are a number of legitimate, prescription medications that can trigger a positive result. Even eating poppy seeds can cause you to test positive.
So to confirm whether you actually have drugs in your system, or if it’s just a false positive, another, more rigorous test must be done. This confirmatory drug test uses more sophisticated technology, to test more precisely. These tests can tell your employers exactly what substances are in your urine, and separate acceptable substances from banned ones.
The good news is, it doesn’t require you to submit to a second test. The confirmatory test takes a second sample from the same initial batch you gave for the first test. The bad news is, if you did have drugs in your system when you took the initial test, you won’t have an extra few days to get them out before the confirmatory test.
The Necessity for Confirmatory Testing
If the initial drug test can yield a false positive, then why don’t employers just perform the more accurate test from the beginning, and eliminate the need for a second one? Well, because the more accurate tests are expensive.
The initial drug test is usually one called immunoassay. It can be done in-house, with a drug testing kit. For the people who pass the first time, that test is enough. The samples where there’s doubt, on the other hand, need to be sent out to a lab for a gas chromatography/mass spectrometry test. These tests are much more accurate, but they’re also much more expensive.
Therefore, to keep costs down, employers start with the standard, immunoassay test. That’s usually enough to clear most of the workforce. They only pay for the lab test when there’s doubt. That’s why it’s called confirmatory testing.
What This Means for You
It’s important to know whether or not you can pass your initial test, so you can be prepared for the possibility of confirmatory testing. If you know that something in your system could turn out a false positive, you can let your employer know in advance, so you can both plan for it.
This is one of the ways that a clean urine sample can help. Using a home drug test, you can compare your own sample with a control sample that you know is clean, to find out in advance whether or not you’ll test positive. Then, you can be prepared for what to do next, rather than being blindsided by a positive result and confirmatory test.
To learn more about drug testing and what your options are, read more on our blog.