This backgrounder is not intended to discuss the merits of drug testing, or go into extensive details on the scientific considerations in setting up a program. It is simply intended to provide an overview of the main issues so that employers considering including testing as part of their alcohol and drug policy have a better understanding of the key issues.


Companies need to make a careful assessment of whether alcohol and drug testing should or should not be included in their overall policy. The introduction of testing in any workplace is a controversial decision, and should be made with full understanding of the role of testing in a comprehensive policy, and consideration of whether it is justified for certain employee groups.

Decisions are needed on who to test, under what circumstances, for what substances, using what technology, and what will be the consequence for failing a test, or refusing to be tested (including confirmed tampering with the sample).


Circumstances for testing can include:

  • pre-employment or pre-assignment (e.g. to a higher risk position) often now referred to as "certification to a safety-sensitive position" where the requirement to pass a test is one part of the certification or qualification process leading to appointment to the position;
  • as a condition of assignment to work at a particular site; (site access)
  • after a significant accident or incident as part of a full investigation;
  • with reasonable cause (i.e. to believe someone is unfit due to alcohol or drug use);
  • on a random basis at a specified rate per year;
  • as a condition of return to work after attending a treatment program or after a policy violation;
  • as a condition of continued employment after a policy violation; and/or
  • as part of a monitoring agreement after treatment.

Some companies may conclude testing will not play a role in the implementation of their policy. Others may conclude testing should be triggered for all employees under certain circumstances, or for certain groups of employees (e.g. high risk) under other circumstances. Each policy must be absolutely clear on when testing applies, and the procedures which will be used, as well as the justification for its introduction.


Existing technology has developed methods to accurately test for the presence of a wide range of drugs. Workplace testing programs authorized through the United States Department of Health and Human Services (DHHS) and accepted throughout North America, focus on six specific drug classes most commonly associated with abuse in the general population.

The standard testing panel is marijuana, opiates, amphetamines, phencyclidine (PCP), cocaine, and alcohol.

Programs are not limited to these substances if there are problems and grounds to "expand" the slate. Many Canadian companies are adding oxycodone to their opiate panel because of the significant problems with it's use and abuse across the country. The U.S. Secretary of DHHS has signed off on the requirement for adding oxycodone to the regulated slate of drugs (January 2012). For the most part, however, additional drugs are generally only tested for in post treatment situations on the advice of the substance abuse specialist.


There are three stages to the testing process: sample collection, laboratory analysis, and medical review and reporting of results. All three stages have been strictly regulated in the United States, and these procedures have been accepted in Canada as meeting the highest standard of accuracy and integrity of the process.

  • Urine specimens are collected under highly controlled conditions at a designated collection site by trained and authorized personnel who ensure privacy during collection, security and integrity of the sample. Chain of custody documentation follows the sample throughout the process, noting everyone who handles it (with every effort made to minimize the number of persons handling specimens).
  • If after a reasonable number of attempts the employee is unable to provide a sufficient sample for analysis, the company will be notified, and arrangements are made for a medical assessment. If there is a medical reason for the situation, the test will be cancelled; if there is no medical reason, this is considered a refusal to test.
  • Qualified laboratories must meet established scientific and technical guidelines for all drug testing programs, and therefore, only laboratories accredited and certified by the U.S. Department of Health and Human Services are used for employee testing programs.
  • After the specimen has been properly collected and forwarded to the laboratory, it is analyzed for the presence of drugs using two steps. The first, an immunoassay test is a screen to determine if a drug is present; if the screening test is positive, a second confirmation test is done using highly technical and accurate procedures and equipment called gas chromatography / mass spectrometry (GC/MS).
  • A sample will only be identified by the lab as positive if the presence of a particular drug is at or exceeds the cut-off level. Although laboratory equipment is sufficiently sophisticated to enable the identification of even minute traces of many drugs, higher cut-off levels are established to ensure accuracy and consistency in drug identification, and to discount minute nuisance intake as from the passive inhalation of second hand smoke, for example.

The positive levels for the five classes of drug tests are indicated in the table below:

Drug Initial Test Levels (ng/ml)* Confirmation Test Levels (ng/ml)*
Marijuana 50 15
Cocaine 150 100
Opiates 2,000
Morphine 2,000
Codeine 2,000
Oxycodone 100 100
6-acetylmorphine 10 10
Phencyclidine (PCP) 25 25
Amphetamines 500 250
Methamphetamine 500 250
MDMA 500 250
MDA 250
MDEA 250

* A ng/ml means nanograms per millilitre. A nanogram is one billionth of a gram.

A millilitre is one thousandth of a litre.

  • If the results of the initial test are negative, the lab will advise the company or its Medical Review Officer that the test was negative and no additional tests on the specimen will be done.
  • If the results of the test are positive on the GC/MS confirmation test, or indicate tampering, this is reported as positive/tampered to the Medical Review Officer (MRO) for review and analysis. This review step will include discussion with the employee to determine whether there is an alternative medical reason for the results. The critical role of the MRO is outlined below.
  • Only when satisfied that it is a true positive or tampered result will the MRO notify the company's Program Administrator of this conclusion; otherwise, it will be reported as a negative.

Tests results provide qualitative and quantitative information indicating whether a specific substance is present in the urine. The concentration of a drug in urine is influenced by several factors: dose of the drug taken, how it is taken, frequency of use, time lapse from drug use to urine collection, amount of liquid consumed recently, time elapsed since last urination, time of day and any recent dehydrating exercise.

For drugs other than alcohol, a confirmed positive test simply indicates that the drug was ingested recently. Tests for alcohol use (breath) are more specific on the degree and timing of impairment, and can identify whether the person was under the influence of alcohol when the sample was collected through standard calculations equating test results to blood alcohol content.

A positive test confirms that laboratory analysis found the drug at or above the prescribed cut-off level. A negative test either confirms the drug was not found in the sample, or that it was present below the cut-off level.

On-Site Testing Devices: Undertaking an initial screen at the collection site (point of collection test or POCT) is becoming increasingly available and are particularly of interest for companies with remote operations where laboratory turn-around time could be longer because of distances. The test device is a "screen" in that it can screen out negative results. However, any result indicated by the screen as "not negative" must be forwarded to a lab for confirmation using the same chain of custody procedure, and a lab positive must be reviewed by an MRO before any employment action is taken.

In addition, companies should only use devices that have adulteration checks; otherwise, tampered samples could never be identified for further analysis at the lab. The U.S. government has approved the use of "mini labs" to do the screening step, but has not yet finalized approval for test cups.

For the most part in Canadian programs, test cups are being used in reasonable cause and post incident testing situations. Normally split sample urine testing is being used for all other testing situations except random, where in non-regulated random testing situations, oral fluid is often collected for analysis in the lab (see below). Some programs in northern Alberta are allowing POCT for site access testing when large numbers of people must have negative test results before getting on a site, and the laboratory process can not turn the volumes around quickly.

Oral Fluid (saliva) testing technology is now available which will allow efficient collection of a sample and analysis in a laboratory following similar security procedures as those for urine drug testing. Although not widely used in Canada at this time, employers are increasing looking at introducing this alternative technology because it is perceived as less intrusive, provides a tighter window to recent use of a drug, and has less potential for tampering as collection is observed. Although not currently approved for cross border regulated programs, the Secretary of DHHS has approved a plan to add oral fluid testing to the regulations.

The only accurate testing devices are those that collect samples for analysis in the laboratory. That is also the system that the DHHS is proposing in its regulations. There have been scientific studies undertaken over the past 6 to 8 years looking for devices that are specific enough to detect the drugs in oral fluid. These studies are being done to support the drugged driving legislation around the world, including under Canada's Criminal Code. To date, the researchers have not found a point of collection oral fluid device that is sufficiently accurate for use in these programs, and therefore none they would recommend for roadside or workplace programs.


Breath analysis for alcohol use is a widely used and accepted technology because breath is the most easily obtained bodily substance and the results are known within minutes of testing. Current-generation breath-alcohol analyzers have excellent accuracy, precision, sensitivity and selectivity or specificity for ethanol in breath specimens.

The concentration of alcohol in end-expiratory breath accurately reflects the alcohol level in the blood and can appropriately interpret the presence and degree of intoxication or impairment at the time the sample is taken.

Specific training and quality control measures are needed to ensure proper administration of the procedure and calibration of the device. Test results are displayed and confirmation results are printed using an Evidential Breath Testing Device. Collection is handled by a trained Breath Alcohol Technician, generally through an external collection agency; a company representative can be trained to operate the equipment if necessary because of unusual circumstances.

  • if necessary, two samples are collected a specific time apart to confirm the blood alcohol correlation;
  • if the first test result is below the designated cut-off, the collection process is completed;
  • if the first test result is above the designated cut-off, a confirmation test will be done after a 15 minute waiting period (but within 30 minutes after the screening test) to ensure the presence of mouth alcohol from recent use of food or hygiene products does not artificially raise the test result;
  • if the confirmation test is different from the initial test, the confirmation results will be considered the final test result, and in all cases, a breath alcohol testing form will be prepared for the company, with a copy for the tested individual; and
  • breath test results are reported directly by the collector to the company Program Administrator.

If after a reasonable number of attempts the employee is unable to provide a sufficient sample to register a breath test result, the company will be notified, and arrangements are made for a medical assessment. If there is a medical reason for the situation, the test will be cancelled; if there is no medical reason, this is considered a refusal to test.


In those situations when a breath analyzer is not available within a reasonable time period, alternative technology can be considered. Usually an alcohol saliva screen is used to "screen out" negative results. If a donor screens above the cut-off level, an oral fluid sample can be collected, sealed and sent to the laboratory for analysis. The device that can be used for this purpose is the one commonly used for oral fluid drug testing (noted above), called Quantisal and is approved by Health Canada. The Canadian laboratory testing oral fluid has developed the proper conversion process for a blood alcohol equivalent.


The process to collect and analyze breath alcohol samples is fully accurate provided an Evidential Breath Testing Device is used by a fully trained breath alcohol technician (BAT). The science on which urine drug testing rests is equally solid provided the process is handled by trained collectors, there is no break in the chain of custody, a screen positive is confirmed by GC/MS analysis and a qualified Medical Review Officer (MRO) reviews all lab positive, adulterated, substituted, or invalid results with the employee.

Although there has been considerable discussion about false positive test results (where a sample is reported to contain a drug that is not actually present above the cut-off level), any possible error in the sample analysis is eliminated through the two-stage screening process and regular calibration of equipment. To avoid any problem, companies should only contract with labs that meet the highest possible standards and are certified by the U.S. Department of Health and Human Services, with trained and qualified collectors, and with an experienced MRO who is fully independent of the laboratory.


It is the Medical Review Officer's job to determine if the laboratory result should be verified as positive, adulterated, substituted, invalid or cancelled after dialogue with the donor. Some the issues they must deal with are:

  • Second-hand Smoke: The cut-off levels are sufficiently high to eliminate exposure to second-hand smoke as a viable reason for a marijuana positive test. Research has found that it would be extremely improbable that subjects would tolerate this type of noxious smoke environment for the length of time required to absorb the level of marijuana necessary to show a positive result. It is possible for the passive inhalation of marijuana to result in detectable levels of cannabinoids in urine given sufficient time and intensity, however there would never be sufficient presence to result in a positive test result.
  • Cocaine: Derivatives of cocaine are in very limited use in certain dental or surgical procedures, which could be verified by the MRO after a cocaine positive finding by the lab.
  • Medications: Certain legal "over-the-counter" or prescription drugs can show positive for metabolites of tested for substances. For example, certain medications and diet pills may contain components that may be detected in the initial screen as an amphetamine-like drug, but these are properly identified by the GC/MS test or in a confirmed prescription. As such, the result would be reported as negative.
  • Codeine (contained in some cold medications) can be metabolized by the body into morphine, and therefore, could show positive for morphine in a test. When morphine is identified, the lab may be asked by the MRO to also look for codeine residues as an indication that the individual did, in fact, take codeine. Also, employees have an opportunity to note on their copy of the chain of custody form any legal or prescription drugs they are taking at the time of collection of the sample and advise the MRO accordingly.
  • having codeine or morphine levels at or above 15,000 ng/ml must provide valid proof they were authorized to use or were validly administered a medication. At levels between 2000 ng/ml and 15,000 ng/ml, the MRO must have evidence of misuse/abuse in order to determine if the test is verified as positive.
  • Poppy Seeds: Depending on the source, poppy seeds eaten with food (e.g. poppy seed cake) can show positive for opiates but the steps taken by the MRO to verify test results would eliminate the possibility that ingestion of poppy seeds would be reported as a positive result.


Tampering can take place when a person knows in advance that he/she will be asked to provide a sample (e.g. primarily in pre-employment/assignment or regular medical situations) where an attempt to substitute a clean sample is used, or in any situation with the help of an additive to "mask" presence of the drug.

Collection agencies and labs are aware of most, if not all, of the methods used to tamper with a sample (e.g. dilute it to move the drug level below the cut-off, use additives to mask the drug, substitute other samples or substances) and take appropriate steps to minimize or eliminate this possibility through the collection procedures and analysis checks. Therefore, there is no requirement for observation at the initial collection stage. However, in the event of confirmed tampering, some companies exercise the option to require observed collection on the next test, and in the case of companies complying with U.S. transportation regulations, there are requirements for observation in certain circumstances.

Additional information on testing programs can be found at:

"The information in this article is not intended to be legal advice, but simply presents an overview of current issues in Canada."

Barbara Butler & Associates Inc.


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