The common types of drug tests used are:
- Urine drug testing
- Hair alcohol testing
- Saliva / Oral fluid-based drug screen
- Sweat drug screen
In urine testing, the urine sample is split into two aliquots. The first aliquot is screened using an analyzer which is capable of performing immunoassay. If it proves to be positive, the second aliquot is analyzed by means of gas chromatography – mass spectrometry (GC-MS) methodology.
Hair alcohol testing detects fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) which lingers in the hair long enough for it to be tested, analyzed and detected. The more alcohol that are consumed, the more of these substances are detected through analysis. Hair analysis has many advantages as an initial screening method to detect present substances of toxic nature. Aside from its non-invasiveness and low cost, this method allows for large number of toxic and essential biological elements to be tested and measured.
The saliva or oral fluid-based method is used to detect consumption of drug or alcohol in the previous days. This method is used more prevalently due to its convenience and also because it is hard to adulterate with contaminants. Furthermore, it allows for the implementation of random testing programs which is proven the most effective type of drug testing. It is used most commonly by employers for either of the following reasons for testing:
- Return to duty testing
- Post accident
- Reasonable suspicion
- Pre-employment
The sweat drug screen is used exclusively by parole departments, child protective services and government institution to detect prolonged drug use. Patches are attached to the skin to collect sweat for a set period of time about 10 to 14 days. To keep from being secretly detached and then reapplied, the patches have security features. After the patch has been worn for the set time period it is removed and sent for analysis in a lab.
Two types of detection methods are used during the laboratory testing. The first is screening test which is applied to every sample that has passed the initial checking of temper-evident seals. The second is known as confirmation test which is applied only to samples that are tested positive during the screening test.
Different types of drug testing are used as mandatory procedures for evaluation purposes:
- Pre-employment drug testing
- Random drug testing
- Post-incident drug testing
- Diagnostic screening
