• four times more likely to injure themselves or others on the job
• five times more likely to file a Workers’ Compensation claim
• three times the medical costs than their non-drug-using coworkers
• 33 percent less productive than non-drug-using employees.
Surprisingly, while employers use this valuable tool in their work environments, many know little about substances that they are asking the medical provider to test for. Here are some answers to the most commonly asked questions.
What drugs are typically tested for? There are many drugs that are looked for during drug testing, though most tests are five-panel tests that follow the Department of Transportation guidelines. These are amphetamines, cocaine, cannabis (marijuana), opiates (morphine and codeine) and phencyclidine hydrochloride (PCP).
How long after use can drugs be detected? Many factors influence how long a drug can be detected in the urine. These include the amount of the drug taken, the frequency with which it is taken, the period of time from ingestion to collection of the sample and the cut-off threshold. The window of detection, or length of time, varies greatly from person to person. The table below is a rough guideline only.
| Amphetamines (speed) | 1-3 days |
| Barbiturates (short/intermediate acting) | 2-4 days |
| Phenobarbital | several weeks |
| Benzodiazepines | 1-3 days |
| Cannabis (marijuana) | 4-30 days |
| Cocaine | 1-3 days |
| Opiates (morphine and codeine) | 2-3 days |
| Phencyclidine Hydrochloride (PCP) | 2-3 days |
| Synthetic narcotics (meperidine, etc.) | 1-2 days |
| Ethanol (alcohol) | less than 24 hours |
Can an employee test negative for a drug that has been taken recently? The cut-off threshold, or concentration, is the amount of drug present in urine that determines whether the result is positive. If the amount of drug in the urine is equal to or more than the cut-off threshold, the test results are positive. If the amount is less than the cut-off threshold, the test is reported as negative. Therefore, it is possible that an employee can test negative for a drug that he or she has used recently.
Do poppy seeds test positive for an opiate? Some types of poppy seeds used on bagels and other baked goods may cause positive test results for the opiate morphine. This is one reason why the results don’t go straight to the employer as positive. The medical review officer interprets the results of the second confirmation test and determines if there are legitimate reasons for positive results.
Can a person test positive for marijuana without smoking it? Passive inhalation, which is the involuntary breathing of secondhand smoke from others, can cause marijuana metabolites to be present in a person’s urine. The cut-off threshold, however, is such that it is extremely unlikely that passive inhalation could produce a positive result.
Can an over-the-counter antihistamine cause a positive test? Taking an over-the-counter antihistamine will not cause a positive result for an amphetamine. IBI