Last updated: May 17, 2021
A blood drug test to determine if employees or employee prospects have drugs present in their bodies is an option rarely chosen. Professional sports teams are subjected to blood drug testing, as are the young athletes that compete in the Olympics, but this method has never been widely embraced by employers. Blood tests are considered to be very intrusive. Other methods can certainly be considered more employee friendly.
The hair follicle drug test, for example, can be administered literally anywhere. Just a small amount of hair snipped close to the scalp is all that is needed. This test has a detection window of 90 days. It can also determine how often the test subject uses drugs; i.e. an occasional or habitual user. Both hair and blood tests are considered very expensive, however.
The cost factor usually plays a large part in an employer’s decision-making process when choosing a drug testing method. The urine test is the most cost-effective testing method and produces highly accurate results.
It is the most widely used method for drug testing in the workplace. It is also the method chosen by the DOT (Department of Transportation) for drug testing all employees working safety-sensitive jobs. The urine drug test has become very commonplace; although considered to be intrusive, employees and employee prospects know what to expect upon arrival at the testing facility.
Another detection option that is becoming more popular among law enforcement agencies is the mouth swab drug test. It is not nearly as invasive as the urine or blood tests and determines if the user is impaired at that moment. These tests can be very useful if impairment is suspected during traffic stops.
But employers don’t often choose the mouth swab test. One reason being the short detection window of only 72 hours prior to the test.
No matter the drug, blood tests have a very small window of detection, as well. Below is a list of 9 commonly abused drugs and the amount of time they can be detected in the bloodstream.
- Amphetamines: 10-14 hours
- Methamphetamine: 24 hours
- Barbiturates: 1-2 days
- Benzodiazepines: 6 — 48 hours
- Cannabis: 6-24 hours
- Cocaine: 12-24 hours
- Codeine: 6-12 hours
- LSD: 0 — 3 hours
- PCP: 12-24 hours
How does a blood test work?
The test must be administered by a medically trained professional and specialized equipment must be used. Upon entering the test site, positive identification of the test subject is made and documented. The blood sample is then extracted with a needle from a vein on the inside of the arm; the back of the palm can also be used. The blood is drawn into one or more small tubes or vials for testing. The entire process is complete in just a few minutes.
The sample will then be transported to the lab for analysis following chain-of-custody protocol.
The test used at the lab is called an immunoassay screening with reflex to definitive testing. It is performed on whole blood specimens using immunoassay screening with reflex to definitive testing.
The wait time for lab results is roughly about a week. This is considered to be lengthy compared to other testing methods, such as the urinalysis or hair follicle test.
What drugs are identified?
5 Panel drug test
- Amphetamine
- Cocaine
- Marijuana (THC)
- Methamphetamine
- PCP/Angel Dust
9 Panel drug test
- Amphetamine
- Barbiturates
- Benzodiazepines
- Cocaine
- Methadone
- Marijuana (THC)
- Oxycodone
- Oxymorphone
- PCP/Angel Dust
10 Panel drug test
- Amphetamine
- Barbiturates
- Benzodiazepines
- Cocaine
- Hydrocodone
- Marijuana (THC)
- Methadone
- Methaqualone
- Methamphetamines
- Opiates
- PCP/Angel Dust
- Propoxyphene
12 Panel drug test
- Amphetamine
- Barbiturates
- Benzodiazepines
- Cocaine
- Ecstasy/MDMA
- Hydrocodone
- Marijuana (THC)
- Methadone
- Opiates
- Percocet/Oxycodone
- PCP/Angel Dust
- Propoxyphene
How accurate is a blood drug test?
Blood tests detect the presence of the parent drug in the bloodstream, not the inactive metabolites. Metabolites are defined as the products created after the body breaks down the drug during the metabolism process.
There is virtually no way to “fake” a blood test. That being said, blood tests produce the most accurate results when determining if someone is under the influence at that moment in time. Unfortunately, the detection window measuring drugs in the system after using is mere hours. This time factor only varies slightly depending on the drug.
Couple that fact with the cost factor. Then, add the longer wait time to receive results. The vast majority of employers don’t figure that equation sums up to being their testing method of choice.
There is certainly a time and place for using blood drug tests. And, yes, they are used by a minority of employers for employee drug screening. However, more likely than not, their use will be primarily reserved for post-accident situations, during a suspected DUI traffic stop, or delegated by court order for some reason rather than being used in the workplace for employee drug testing.
What do the results mean?
Positive
A positive result indicates that drugs have been detected. Employers are notified immediately of the results and the drug policy protocol in place will be followed from that point.
Negative
A negative result indicates no drugs have been detected.
Inconclusive
Inconclusive results are rare, but there is always a minute risk that they can happen. This means that for whatever reason no result can be determined one way or the other. The test must be retaken.