Workplace Drug Testing BLOG

Pre-employment Drug Testing

Maintaining a drug-free workplace, is a crucial part of workplace safety. Taking this preventive step has proved to reduce the risk of drug-related work accidents. It is important to understand what employee drug testing entails and why it is beneficial for the workplace.

Next is what you need to know about Pre-Employment Drug Testing as well as information on the types of drug tests employers utilize for the screening of potential applicants and employees. Also see information related to what type of drugs companies use for the testing of employees.

What is Pre-Employment Drug Testing?

A Pre-Employment Drug Test is a screening service used to determine whether a potential hire abuses drugs or alcohol. As part of the application process, it may be a requirement that the prospective applicant undergoes a drug screening test. Depending on state law and company policy, employers may perform a screening test prior to the proposal of a job offer or as a contingency for a job offer. Federal employers are required to follow drug test procedures created by the Substance Abuse and Mental Health Services Administration (SAMHSA).

What drugs will my potential employer test for?

For Pre-Employment drug screening, most employers require the standard 5-Panel Drug Screen or what is sometimes referred to as the SAMHSA-5. The above test is used to test for the following substances:

  • Amphetamine/Methamphetamine
  • Cocaine
  • Opiates (heroin, codeine, morphine)
  • PCP (phencyclidine)
  • THC (the main psychoactive component in cannabis)

The 10-panel drug test is also widely used by several employers. It specifically tests for recreational drugs and prescription meds like Valium, Xanax, Ativan, Rohypnol, and other weight-loss drugs.

  • Amphetamine
  • Barbiturates
  • Benzodiazepines
  • Cocaine
  • Methadone
  • Methamphetamine
  • Opiates (heroin, codeine, morphine)
  • PCP (phencyclidine)
  • Propoxyphene
  • THC

Employers may request various other tests to determine substance abuse. An employee’s test of choice depends largely on the hiring position in question. Safety or security sensitive positions may involve more extensive drug testing. No testing or screening may be performed without the prospective candidate being notified of the test prior to the testing.

When are workplace drug tests administered?

The purpose of a clearly written drug testing policy is to outline, among other things, just exactly under what circumstances employee drug testing is to be done. Employers cannot indiscriminately order drug tests on any or all of their employees unless they explicitly state it in their drug-free workplace policy, lest they are sued for discrimination.

  • Pre-employment Drug Screening
  • Random Drug Testing
  • Reasonable Suspicion Testing   
  • Post-accident Testing
  • Return to Work Testing 
  • Follow-up Testing

Drug Testing Methods Used in the Workplace

Employers use a variety of employment-related drug and alcohol tests. Types of drug tests that confirms the presence of drugs or alcohol, include Pre-Employment Drug Testing. This is a powerful way to reduce or eliminate accidents in any workplace. There are many ways to conduct Pre-Employment Drug Testing:

  • Urine drug tests
  • Saliva drug tests
  • Blood drug tests
  • Hair drug tests
  • Breath alcohol tests

What is the most common drug testing method used in Pre-Employment?

The Urine Test is a test that most of the job applicants will likely encounter during their job hunting. It is the most widely-used method.

The employee is handed a Urine cup and is directed to the restroom with toilets with blue water. You are not allowed to have any personal belongings on you as person. You may be requested not to wash your hands, or not to flush the toilet before handing in your urine sample.

How long does it take to receive the drug test results?

Labs generally deliver blood test results as fast as they deliver urine test results. For most labs, results are available within 24 hours after the specimen testing . In case of physical delivery of the results, results can be available within 48 hours or more. If results are positive, one can look at a turnaround time of three days after the test.

How long do drugs stay in the system?

Different substances have different detection times in the body, depending on the following factors:

  • Metabolism – People with faster metabolic rates are able to expel toxins faster so the window of time any drug may be detected in their system is generally shorter. Conversely, the drug detection time for a person with slow metabolism tends to be longer. Metabolism is a factor of age, body type and physical activities (sedentary vs. active) and physical condition (illness/wellness). Older people tend to retain drug residues longer.
  • Body fat – Fat tissue stores some drug metabolites like THC and PCP. And a person with more fat tissue tends to have a slower metabolism as well. Longer drug detection times can be expected.
  • Intake method – How long any drug stays in the body is also a factor of the manner by which that drug was taken. For example, marijuana that was eaten takes longer to flush out than if it was ingested thru smoking.
  • Urine pH – Human urine is naturally acidic but the lower the urine’s pH value the shorter the drug detection times.
  • Chronic vs. Occasional use – Chronic users will have developed some tolerance to their drug of choice and therefore are able to flush the toxins out faster, resulting in shorter detection times.

Approximate Drug Detection Times






3-5 days

Up to 90 days


2-4 days

1-3 days

7-90 days


3-5 days

1-3 days

7-90 days


2-4 days

1-3 days

7-90 days


2-4 days

1-3 days

7-90 days

Ecstasy (MDMA)

1-3 days


15-30 days

6-12 hours

7-90 days


7-14 days

1-3 days

7-90 days


2-4 days

7-90 days


4-7 days


3-7 days


3-5 days


1-2 days


2-4 days


2-4 days


2-4 days


2-4 days

What Can Cause a False Positive Drug Test?

There has been reporting of false-positive results for the following formulary and nonprescription medications:

  • Brompheniramine,
  • Bupropion,
  • Chlorpromazine,
  • Clomipramine,
  • Dextromethorphan,
  • Diphenhydramine,
  • Doxylamine,
  • Ibuprofen,
  • Naproxen,
  • Promethazine,
  • Quetiapine,
  • Quinolones (Ofloxacin and Gatifloxacin),
  • Ranitidine,
  • Sertraline,
  • Thioridazine,
  • Trazodone,
  • Venlafaxine,
  • Verapamil, and a nonprescription nasal inhaler.

False-positive results for amphetamine and methamphetamine were the most commonly reported.

False-positive results for methadone, opioids, phencyclidine, barbiturates, cannabinoids, and benzodiazepines were also reported in patients who take commonly used medications.

The most commonly used urine tests for the screening of drugs of abuse, are immunoassays. False-positive results for drugs of abuse have however been reported when a number of these rapid-screening test products were used for testing. Relevant test results should be validated additional analytical methods, including gas chromatography-mass spectrometry.


What does a faint line on a drug test mean?

If a faint line appears in the Test Region of a drug test, this still counts as a NEGATIVE TEST RESULT. Drug test results do not vary based on the intensity of the colored lines. This means that even if the line is very faint, the test has not found any trace of that specific substance.

What does a negative drug test mean?

A negative drug test does not necessarily mean the donor has never used any of the substances being screened. If a preliminary drug test result is negative, this could mean that drug metabolites in the donor's system did not meet or exceed the cutoff concentration levels established by SAMHSA. In order for a test result to be positive, a certain quantity of metabolites is required to react with the built-in test strip reagents.

How accurate are at home drug tests?

Most home drug tests are FDA Approved to perform just as well as corporate drug tests. A very faint line on a home drug test is indicative of a negative test result, as mentioned above.