Drug Testing Methods

The term “drug testing” is defined by the use of chemical technologies to inspect biological samples to screen and detect the evident use of a drug. The most commonly used samples for testing are urine and blood, hair, sweat, and saliva.

There are many reasons for the use of drug tests. Some drug tests are requested from doctors for medical reasons, or requested by employers to make sure that employees are not working while under the influence of illegal drugs. As mentioned above, drugs may be detected by testing samples of urine, blood, or hair. The following sections will summarize the various types of drug testing methods.

Employers have many options for drug testing methods available depending on how many substances are being screened. The test sample can vary from the following:

  • blood
  • urine
  • hair
  • saliva
  • sweat
  • breath

It is important to understand the different types of drug and alcohol tests available.

A Breathalyzer can be used to test blood alcohol levels. This is used if an employee is suspected of being intoxicated at the workplace. A breath alcohol test can only test for current blood alcohol levels and does not indicate past use.

With a blood test method, blood is drawn to check the number of drugs or alcohol in the system. Blood tests for employment drug screenings are generally used to find illegal substances. The most commonly screened drugs with a blood test are:

  • marijuana
  • amphetamines
  • cocaine
  • opiates
  • methamphetamines
  • alcohol
  • nicotine

A drug test used on hair samples shows the furthest history for viewing for past drug use. Drug tests that use hair samples will show a three to a six-month history of drug use. Hair tests will not show the use of alcohol, but can be screened for:

  • methamphetamine
  • marijuana
  • cocaine
  • opiates
  • phencyclidine

Some companies prefer drug testing with saliva. With this method of screening, a sample of the employee’s saliva is taken from inside the mouth. The saliva is then tested and shows drug use as recently as the last few hours and up to a few days.

Urine tests are one of the most common methods, with this type of test, drug use can be detected for different periods of time. Generally, substances can be detected for up to a month. The most common drugs tested with urine samples include:

  • alcohol
  • nicotine
  • amphetamines
  • marijuana
  • cocaine
  • opiates
  • methamphetamines

According to the National Council on Alcoholism and Drug Dependence, it costs employers about $81 billion per year in damages as a result of employee drug abuse.

Employers can reduce their losses when it comes to drug testing by working with a direct drug testing lab to get accurately verified results. Most labs have either a five-panel or 10-panel screening.

The Five-Panel screen tests for:

  • Methamphetamine and Amphetamines
  • Cocaine
  • Opiates including codeine, heroin, and morphine
  • PCP or Phencyclidine
  • Marijuana (THC)

The 10-panel screening will have employees tested for:

  • Methamphetamine
  • Cocaine
  • Amphetamine
  • PCP or Phencyclidine
  • Opiates including morphine, codeine, and heroin
  • Marijuana (THC)
  • Methadone
  • Propoxyphene
  • Barbiturates
  • Benzodiazepines

There are also other tests to detect less commonly seen drugs such as:

  • Quaaludes
  • Hallucinogens
  • Inhalants
  • MDMA
  • Anabolic steroids

Different drugs have various windows of detection. The detection window is the amount of time that the drug will remain in the employee’s system.

Approximated detection windows for different substances are:

  • 5 hours for 1 oz. of alcohol
  • 48 hours for amphetamines
  • 2-10 days for barbiturates
  • 2-3 weeks for Benzodiazepines
  • 2-10 days for cocaine
  • Less than 1 day for heroin metabolite
  • 2-3 days for morphine
  • 8 hours for LSD
  • Up to several weeks for marijuana
  • 2-3 days for methamphetamine
  • 2-3 days for methadone
  • 1 week for PCP or Phencyclidine

It is important to note that prescription medication may also be detected and give a false positive for illegal drug use.

Employees taking prescription medications should notify the testing facility so that it can be documented and verified. Some of the standard prescription medications that may show a false positive includes:

  • Penicillin
  • Adderall
  • Novocain
  • Oxycodone
  • Hydrocodone
  • Certain weight loss medications
  • Valium
  • Xanax
  • Ativan
  • Rohypnol

Drug Testing in the Workplace

Pre-employment drug tests can improve company turnover rates, improve absenteeism, and improve overall workplace morale. When employers are suspicious about whether a current employee is using illegal substances, they may ask the employee to take a drug screening test. There are many drug testing methods available to request. Drug testing is most effective when requested based on a clearly written policy available for all employees to acknowledge, along with educating employees about the potential dangers of alcohol and illegal drug abuse.


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