The Science Behind Employment Drug Testing

Today, employment drug testing is considered to be a “best practice” and should be a “condition of employment” which businesses of all sizes and industries should employ. Drug testing falls into many categories, however, the basic drug test utilized within most corporate drug testing programs looks to detect the following five categories of substances:

  • Cannabinoids, which include marijuana and hashish
  • Cocaine, including crack and benzoylecognine
  • Opiates such as heroin, opium, codeine and morphine
  • Amphetamines, including methamphetamines and speed
  • Phencyclidine, including PCP and Angel Dust

More sophisticated or “10 Drug” testing programs will also test for:

  • Barbituates
  • Methaqualone (qualuudes)
  • Benzodiazepines (i.e., various tranquilizers)
  • Methadone
  • Propoxyphene (i.e., Darvon compounds)

There are also employers who test for alcohol, LSD, hallucinogens and inhalants.

What is particularly important for organizations using drug testing is to understand the potential for false positive readings based on an applicant’s use of legally prescribed medications and/or over-the-counter drugs such as Ibuprofen, Midol, Nuprin, Sudafed, Vicks Nasal Spray, Vicks 44, Neosynephren and Ephedra diet products. With this in mind, one of the most important questions to ask applicants when drug testing is, What medications you are presently taking or have taken in the last 30 days?, as many drugs to remain in the system beyond the day they were taken. How long any drug remains in the system is a function of the drug, as well as the individual’s size, metabolism and body chemistry. For example, amphetamines typically remain 2-3 days, barbiturates remain 1 day to 3 weeks, anabolic steroids remain for 14-30 days and valium may stay in the system for as long as 30 days.

Drug tests come in two forms: urine sample tests or oral fluid tests. By and large, most small- to medium-sized employers and a good majority of large employers elect to outsource drug testing to a third-party administrator or their Professional Employer Organization (PEO). These organizations have relationships with recognized laboratories and have in place pre-employment drug testing programs, which also encompass policies and procedures for handling applicants with positive or abnormal test results. Further, because of the large volume of testing they manage, they can pass on scales of economy to their clients who, handling drug testing on their own, would incur higher costs. In these instances, the results will be subject to further evaluation by a Medical Review Officer who will provide the final results and analysis.

It should be noted that there are do-it-yourself drug testing kits on the market and while they may seem like a good idea for the average scenario, they can present challenges when false positive results emerge. Then, the employer must still seek out a laboratory to analyze and confirm the actual outcome prior to making any judgment or hiring decision regarding the prospective employee.


On March 8th, 2011, posted in: Help For Human Resources, Small Business Tips by
No Responses to “The Science Behind Employment Drug Testing”
Leave a Reply