Urine is probably the most popular means of drug testing (others being saliva, blood, sweat, breath and hair) to determine if illegal substances have been taken.
It is common for employers to order random drugs test for current employees, and also before offering a position to a prospective employee.The person will be informed that they need to attend an appointment for a drugs test at a specific laboratory. Once there, they will be asked to provide a urine sample.
Various measures will be in place to make sure that the sample can not be swapped, diluted or contaminated.
There are different tests available, some more in depth than others but the most common is the 5 panel test (shown above) which is dipped into urine, and then a cap is replaced over the test strips.
After just a minute or so, the results are clear. Two lines is a negative result; one line is positive.
The standard five panel test can detect the following drugs:
Cocaine
Marijuana
Heroin, morphine, codeine
Phencyclidine
Amphetamines
For government and health related jobs, etc. A more in depth test will be used which tests for a greater variety of drugs.
Results are usually given to the employer in a few days, though if a positive result is found, the lab will often call the person who has been tested, to determine whether there is a legitimate reason for failure, i.e prescription drugs which can, and do, sometimes show up.