Here are some urine drug testing facts. If you've applied for a job recently, chances are you've have to do a urine drug test. There are some things to know about the test, that may help you understand the procedure better. Typically the urine test, also known as the SAMHSA-5, looks for marijuana, cocaine, opiates, PCP, and amphetamines. Some companies also offer the option of testing for Barbituates, Hydrocodone, Methaqualone, Benzodiaepines, Methadone, Propoxyphene, Ethanol, or MDMA.
Most companies choose to use urine drug tests because they are the least expensive and least intrusive to perform. Urine tests are able to detect drug use within the past week, or even further back if the sample is from a habitual user. However, the test cannot detect the amounts of the drug, the method that was used (inhaled, intravenous, ingested) or exactly when the drug entered the system. The test typically is only able to detect a drug above a certain amount. Any amount less than that will result in a negative test. If the urine test is positive, it is tested again by gas chromatography/mass spectrometry. It is very unlikely to receive a false positive using this method.
The lab will test the temperature of all urine samples to insure that it is a fresh sample and not a substitute. If it is suspected that the sample has been tampered with they may also test the pH level, and creatinine level. It is possible to mislead the test by ingesting large quantities of liquid beforehand. This will dilute the urine, and possibly make the amounts of drug that are present lower. However, the lab may request a second sample if the first is too diluted.