What are the Different Types of Drug Tests?

February 13, 2023
Checkr Editor

Many American companies require employees to comply with workplace drug testing policies. Depending on federal, state and local laws, industry requirements, and the organization’s needs, the types of drug tests will vary.

The organizational case for mandating different drug tests is clear. From a business perspective, illegal drugs, certain prescription drugs, and the presence of alcohol may contribute to increased absenteeism and decreased productivity. Plus, businesses are responsible for providing a secure working environment to keep their employees safe from harm.

It’s good practice to be transparent about your drug testing methods if you want to attract and retain the best talent for your team.  This can avoid applicant confusion about the types of drug testing they must undertake, when the drug testing is conducted, and how it works.

Types of drug tests and commonly screened drugs

Different kinds of drug tests are used to identify specific substances and how long they have been in an applicant’s or employee’s system. Below are some of the most common drug tests, and their uses.

Urine testing

Urine testing, also known as urinalysis, is the least invasive type of drug testing. It’s also the most commonly used and the approved method of testing for federally mandated drug screening. Urine testing involves checking samples for the presence of metabolites. Metabolites are trace residues that remain in a person’s system even after the effects of drug use have worn off. This means that a positive result doesn’t necessarily indicate that someone is under the influence at the time of the test, only that they had been at some point prior to the test.

Hair testing

Hair testing is considered one of the most reliable types of drug tests due to its cheat-proof nature. It also has the longest detection window. Because hair testing is able to identify substances up to 90 days after use, it is often used to detect repeat drug use. Impervious to concealment by bleaches or dyes, hair tests also eliminate the opportunity for employees to abstain from substance abuse for short periods before testing. Analysis of hair by comparative testing can reveal exactly which drugs were taken, for how long, and when usage stopped.

Oral fluid testing

Also known as a saliva test or mouth swab, analyzing oral fluids is one of the most cost-effective types of drug test. They are quick, time-sensitive, and can often be collected on-site. Identifying residual drugs using oral fluid testing is particularly efficient because samples can reveal drug usage between just a few minutes and up to 48 hours prior to collection.

Typically, the drug testing methods listed above check for the presence of the following controlled and illicit substances:

  • Marijuana/THC
  • Cocaine
  • Amphetamines (including MDMA and methamphetamine)
  • Opiates (including heroin, codeine, morphine, hydrocodone, oxycodone, hydromorphone, and oxymorphone)
  • Phencyclidine (PCP)

Other types of drug tests

Of course, it’s not just illegal substances that employers need to screen for. The presence of alcohol also needs to be monitored—especially for employees who will operate vehicles, machinery, or hold otherwise safety-sensitive positions.

Breath alcohol testing: In contrast to other drug test types, breath alcohol tests can only identify an individual’s level of intoxication at the time the test is administered. Most breathalyzers can detect alcohol up to twelve hours after the consumption of a single drink. This level of accuracy explains why it’s the most commonly used type of drug testing in many workplaces.

Blood tests: Blood screens can be used to test for both alcohol and illicit drugs. However, they are expensive and invasive and are therefore seldom used. As with breathalyzer testing, blood samples can only reveal substances that are present at the time of testing.

Why employers drug test

Alcohol and drug abuse is a bigger problem than many people realize. According to the 2021 National Survey on Drug Use and Health by the Substance Abuse and Mental Health Services Administration (SAMHSA):

  • 61 million Americans aged 12 and older admitted to using illicit drugs within the previous year.

Alcohol and drug abuse can create health and safety hazards for all employees, which in turn can cost organizations hundreds of thousands of dollars. Some common reasons for employers to administer drug tests may include:

  • Restricting the hiring of alcohol or drug addicts;
  • Preventing existing employees from abusing alcohol and drugs;
  • Ensuring a safe working environment for everyone;
  • Reducing absenteeism and lateness;
  • Lowering the risk of workplace accidents;
  • Protecting business partners and the general public;
  • Identifying employees who need help to overcome drug/alcohol problems;
  • Maintaining high productivity and employee morale;
  • Reducing the cost of healthcare and short-term disability claims;
  • Complying with local, state and federal laws and regulations; and/or
  • Benefiting from Workers’ Compensation Premium Discount programs.

How drug tests are conducted and their reliability

Different types of drug tests necessitate different collection techniques. Regardless of the type of drug tests a company chooses to use, steps must be taken to prevent the tampering, manipulation, or substitution of samples, and the falsification of results.

Urine samples are often conducted in bathroom stalls. Direct supervision could be considered an invasion of privacy, so multiple measures are taken to ensure fair play, including:

  • The use of specific stalls;
  • Putting dye in the toilet water; and/or
  • Turning off the water supply.

Test administrators may also impose special instructions, such as avoiding water intake and urinating for a couple of hours before testing. Employers should always be aware of any federal, state and local laws and regulations which may provide additional guidance on how urine samples are collected.

Other drug test types only require small samples which are easier to collect under direct supervision. SAMHSA, the federal agency tasked with leading public health efforts to combat substance abuse, has stringent guidelines to ensure that no specimens can be interfered with after collection:

  1. Official chain of custody documentation details each sample’s collection, handling, storage, analysis, and disposal.
  2. Samples are split so that a second test can be performed in the event of a positive result.
  3. An initial screen is undertaken. In the case of a positive outcome, the second analysis is performed to eliminate the possibility of a false positive.
  4. Using the second part of the split sample, a confirmation assessment is conducted. Only if both tests return the same result can a positive outcome be recorded.

A positive result is determined by a minimum baseline presence of a drug, known as the cut-off level. SAMHSA guidelines set cut-off levels relatively high to account for passive exposure and random false positives.

No type of drug testing is 100% reliable. Still, false positives are less likely than false negatives—provided strict collection, handling, and analysis procedures are followed.

Suppose the initial and confirmation screenings both come back with a positive result. In that case, a licensed doctor specializing in substance abuse will review the results to ensure the chain of custody was adhered to, the specimen was stored correctly, and the correct chemicals were used for testing. The licensed physician will also contact the individual directly to obtain any additional information around the positive result, after which, the specialist will declare the outcome. Some prescribed medications can trigger positive results. In those cases, if the medication in question is taken at the recommended dosage and under the direction of  a licensed physician, the test is declared negative.

False negatives are more common than false positives primarily due to the timing of sample collection. Different kinds of drug tests will identify the presence of substances at varying optimum periods (after ingestion). It’s therefore possible an employee with a regular drug habit could return a negative test if the sample was collected too early or too late from their last use.

When drug tests are conducted

There are several scenarios in which employers may conduct drug tests. The type of drug tests used in each case may vary depending on the employer’s purpose.

Pre-employment: Pre-employment drug testing helps organizations meet business objectives, mitigate risk and ensure safety in the workplace. In some sectors, pre-employment drug testing is mandatory. For example, federal Department of Transportation (DOT) regulations stipulate that all new employees need a negative drug test on file before commencing duties.

Post-accident: If an employee is involved in—or is the cause of—an accident, an employer may require a drug and alcohol test for the affected employee. This is especially true in heavy industries and/or in situations where injuries or fatalities occurred.

Random: Some companies require regular random testing to ensure the workplace remains drug-free. These employers must ensure that the selection process is without unlawful bias or discrimination. Managers may request a test based on observed behavior but there must be reasonable cause. Testing employees based on their age, gender, race, religion, sexual orientation (or other protected categories under federal, state or local laws) could result in discrimination claims brought against the employer

Periodic: Unlike random testing, periodic drug screening is scheduled and conducted regularly throughout the year. They are often bundled into an employee’s annual physical examination and may also be requested if an employee transfers departments or enters a new role.

Return-to-duty: Following a previous violation, employees may be asked to retake tests until they are deemed fit to return back to duty.

Reasonable suspicion: Subject to (any) applicable laws, employers may request drug testing if an employee shows visible signs of inebriation or early warning signs of substance abuse. Example indicators include:

  • Slurred speech;
  • Uncoordinated movements;
  • Excessive sweating;
  • A scent of alcohol;
  • Evidence of needle marks;
  • Personality change;
  • Mood swings;
  • Erratic behavior;
  • Social withdrawal;
  • Complaints from customers or colleagues; and/or
  • Increased tardiness and decreased work output.

Additional drug testing information

Aside from the what, why, when, and how, below are the most frequently asked questions about drug testing.

  1. Is drug testing legal?

There is no federal prohibition against employer drug testing.  However, states and localities may regulate the types of drug tests employers can require as well as restrict the positions for which drug testing may be required, for example to safety-sensitive positions. It is employers’ responsibility, working with their legal counsel, to implement a drug testing policy and program in accord with applicable federal, state, and local laws and/or regulations.

  1. Who pays for drug testing?

It’s standard practice for the employer to pay for drug testing, and under the federal Fair Labor Standards Act (FLSA), the employee’s time in taking the drug test is considered hours worked.

  1. Who can see the results of a drug test?

No matter the type of drug test, privacy protections prevent the public release of drug and alcohol testing results.  Employees may need to sign a release for their employer to access the results. Employers should consult their legal counsel to ensure their drug testing policy and procedure(s) are in accord with any applicable federal, state or local privacy laws.

Choose Checkr

Need help with drug and alcohol testing for your organization? Checkr offers onsite oral fluid drug testing that you can administer directly at your work locations. For clinic-based testing, our nationwide network of more than 600 labs can customize pre-employment drug testing that is tailor-made for your hiring needs.

Contact our team today to learn more about how to protect your business, retain the best employees, and maintain a safe work environment with our modern approach to employee drug and alcohol testing.



Nothing in Checkr’s Blog should be construed as legal advice, guidance, or counsel. Companies should consult their own legal counsel about their compliance responsibilities under the FCRA and applicable state and local laws. Checkr expressly disclaims any warranties or responsibility or damages associated with or arising out of information provided.

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