Employers request drug tests for specific reasons. Usually, tests are done on a urine sample given by the employee.
First, drug testing may be done as pre-employment screening. The purpose is to screen potential employees for the presence of illegal drugs. Testing can be requested as a condition of being considered for employment.
Second, testing may be done for cause. After an accident or near miss, employee impairment may be considered as a possible cause of the incident. It also may be a condition of return to work when an employee in a safety sensitive occupation has a prior history of substance abuse and so agrees to periodic testing.
A third reason, to test for cause, is when an employee shows difficulties with job performance or physical behaviour and drug abuse is a possible reason.
A fourth reason – random testing – is perhaps the most controversial. In random testing, employees are selected by chance, often by a computer, to be tested.
To provide a valid urine sample, the employee is asked to use a washroom where the taps have been shut off and a blueing agent put in the toilet bowl. This is done so that the urine specimen cannot be diluted. In some cases, urine donation must be observed. However, in most cases it is not. The temperature of the urine is measured to make sure it is fresh. If it is below a certain temperature, it is rejected.
The urine sample must be kept in safekeeping at all times so that no one can tamper with it. Legal obligations must be satisfied. This requires complete and thorough checking to be sure specimens are not mixed up and that the laboratory does the testing accurately.
A large survey of company employees identified attitudes towards drug testing. Pre-employment testing, testing for cause, and testing after an accident are generally acceptable to many employees in safety sensitive positions. However, many feel random testing is not acceptable and an unnecessary violation of privacy. There are good arguments for and against drug testing in the work place.
Arguments in favour suggest that any way of increasing safety of workers or the general public should be encouraged. The legal requirement to test transportation industry and nuclear power plant workers is a good example.
Some work places, such as the oil fields, are in remote locations where workers are away from home and there is little in the way of medical resources. Such jobs are safety sensitive. A lack of access to alcohol or drug treatment programs may exist. Perhaps screening these workers for substance abuse issues makes sense.
When applying for jobs where drug testing is required, most people know in advance that they must provide a urine specimen. So, the results of any test may only show that the applicant has not used drugs in the past few days. On the other hand, this requirement does send a message to new employees that the company is concerned about substance abuse.
Arguments against drug testing suggest that it is not a good tool for assessing impairment. For instance, if one smoked marijuana on a Friday night, evidence of this would still appear in the urine on Monday morning. Although the most common cause of work place impairment is alcohol, testing urine for it is not particularly accurate.
Random drug testing misses other factors that can also affect job performance. Lack of sleep, marriage problems, other family stressors, fatigue, or mental disease can all create equal difficulties.
Studies have compared the performance of people with a full bladder with those who have had up to twice the legal limit of alcohol. Individuals with a full bladder performed more poorly than those who had used excessive alcohol.
Another study was done with individuals on a regular dose of narcotics for a medical condition. These people rapidly became able to withstand any effects of the medication on mental function. Within a few weeks on a regular dose, they had no more problems with mental function than any other worker.
Valid arguments exist for and against drug testing. Pre-employment testing, testing for cause and testing after an accident are generally acceptable to many employees in safety-sensitive positions. Random testing, however, is often seen as an unnecessary violation of privacy. Drug testing does not necessarily measure impairment in the work place. It is very expensive and is subject to both legal and human rights concerns. While drug testing may avert at least some accidents, no precise numbers can be given. It will miss other important causes of impairment.