Your questions, answered

Drugs are incorporated into growing hair. Because scalp hair grows at an average rate of approximately 1 cm per month, the analysis of a hair sample can provide retrospective evidence of drug use. Analysis of 3 cm of scalp hair should detect drug abuse during the previous 3 months approximately (it takes roughly one to two weeks for drugs to reach the part of the hair that can be sampled).

Yes. Modern technology has advanced so much in recent years that it is possible to detect the low concentrations of drugs present in hair.

There is no statutory scheme for hair testing in family and workplace cases. Accredited laboratories work in line with the consensus guidelines of the Society of Hair Testing (soht.org).

In the absence of a specific drug request, hair samples are screened for a standard panel which includes a range of commonly abused drugs.

Non-negative screening results are confirmed by a more specific method at an accredited laboratory before they are reported. Results are read alongside the case history.

Hair samples are taken by trained collectors at a central Belfast location, although collections can also be arranged at other locations, including Dublin.

A sample of hair (preferably two samples of scalp hair strands) about the width of a thin pencil is collected from the back of the head. Non-scalp hair (body, axilla) can be used if scalp hair is not available, and body hair can sometimes be used for alcohol too. Your collector will advise. The collector seals and labels the specimen and completes chain-of-custody paperwork, so the specimen is properly identified and tracked throughout the testing process.

Drug abuse can be detected many months after the last instance of use — 3 cm / 3 months is standard analysis practice. The detection window is longer with non-scalp hair.

It is possible. In the absence of drug metabolites there is some possibility that drug presence in hair was due to environmental exposure — less likely with non-powdered drugs (tablets). The presence of metabolites and the concentrations detected make environmental exposure much less likely as an explanation, alongside the laboratory’s washing procedures.

The presence of the drug will be reported to the organisation requesting the test — usually a solicitor or social worker.

Hair testing is well suited to supporting a statement of abstinence over a defined period. Urine analysis can also be used but the detection window is much shorter. Hair and urine are often used together — the urine picks up more recent use.

Alcohol itself cannot be detected in hair, due to its volatility. However, minor alcohol metabolites do become incorporated into hair, and measuring these can show the pattern of drinking over a period of months.

There are two types: ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs).

A low EtG result is consistent with abstinence or light drinking but does not rule out occasional drinking. A raised result counts against abstinence. FAEE can be added as a second marker. Bleaching, dyeing and perming can reduce both alcohol markers, and hair products containing ethanol can raise FAEE, so please tell the collector about any treatments. Hair analysis is not totally definitive — each case should be judged on its own merits, and results are read alongside the case history.

Yes. The sample selected for EtG analysis can also be used for drug analysis.

A Medical Review Officer: a qualified physician who reviews and interprets a confirmed laboratory result on behalf of the employer, independently of the laboratory. Results go to your employer in the usual way. MRO review is available on request once the laboratory result is back. The doctor may consider your medical history and prescribed medication when assessing the result, and may ask to speak with you.

When samples are sent to the laboratory for analysis, a chain-of-custody form is completed. Laboratory reports are linked to a donor’s sample by unique identifiers; donor names are generally not included in the laboratory report.

Your employer has the right to set up a testing programme for alcohol and drug abuse. Under most circumstances the types of tests, and the drugs included in the panel, are determined by your employer. There are standard panels used by many employers, and local drug abuse patterns may also be taken into consideration.

A cut-off level is a drug concentration value used to determine whether a sample is considered positive or negative. Cut-offs are based on recommendations from international guideline bodies. They can differ between guidelines and laboratories. If a test were too sensitive (a low cut-off), there could be a danger of a positive result from innocent exposure — such as passive exposure to cannabis smoke.

Non-negative screening results are confirmed by a more specific method at an accredited laboratory before they are reported. Results are read alongside the case history.

Most company drug testing policies call for some form of disciplinary action, up to and including dismissal.

Collection usually occurs on company premises. Sometimes the collection may take place at NIVHA premises.

A urine collection site must at a minimum provide: an enclosure where privacy for urination is possible; a toilet; a source of water for washing hands (alcohol-free wipes can also be used); a suitable writing surface for paperwork; and restricted access so the site is secure during collection. An oral fluid collection site does not require toilet facilities.

Testing is a two-stage process. First, an initial screening test is administered — on-site or in the laboratory. If it is non-negative for one or more drugs, a confirmatory test is conducted for each identified drug using a different, more sophisticated analytical process in the laboratory. Samples are collected by a trained person, sealed, labelled and documented on a chain-of-custody form. A urine specimen is divided into two or three portions at collection; only the primary specimen is opened for testing, while the other remains sealed at the laboratory. If the confirmation test is positive, the employee can request that the B sample be sent to another accredited laboratory — essentially an opportunity for a second opinion.

You do not have to strip or wear a gown. The collector can ask you to remove unnecessary outer garments such as a coat or jacket that might conceal items that could be used to tamper with a specimen, and may ask you to empty your pockets if tampering is suspected. Oral fluid collection is much less susceptible to tampering or adulteration.

Not very much. Your collector will tell you how much is needed.

If you are unable to provide a specimen initially, water is offered. If after a reasonable waiting time a specimen is not forthcoming, the employer is informed. It may then be necessary to determine whether there is a medical reason, and the case can be referred to a Medical Review Officer.

Urine — it depends on the drug, the amount and your metabolism. Many tested drugs can be detected for several days after use; cannabis metabolite can be detected for longer, up to several weeks in regular users. Oral fluid — in general the detection window is shorter than for urine, depending on dose.

Research has exposed non-smoking individuals to heavy concentrations of cannabis smoke in confined spaces. Although non-smokers can absorb some of the drug, cut-offs are set so that a positive from trace or passive exposure is very unlikely.

If you are taking prescribed medication, you should continue taking it. You will be given the opportunity to declare any medication at the time of sampling. There is no reason not to eat and drink as usual.

Laboratories use cutoff limits to determine whether a specimen is positive or negative. A negative result indicates the level of the drug or alcohol being tested for is either not present or below the cut-off concentration. A positive result indicates the substance is present above the cutoff limit.

Cut-offs are based on recommendations from international guideline bodies. They can differ between guidelines and laboratories.

Workplace testing does not measure impairment. It shows whether a substance has been used within the detection window, and this is assessed against the employer’s safety-based policy.

If a screening test flags a sample, it is called a non-negative rather than a positive. Some over-the-counter and prescription medications can give rise to non-negative screening results, but confirmatory testing identifies exactly which substance is present, so a medicine that cross-reacts on screening is not reported as an illicit drug. A confirmed prescribed drug is reviewed against declared medication. What is generally called a false positive is simply a screening result that has not been confirmed as a target drug.

Where an MRO review is requested, it is carried out by a suitably qualified professional, typically a registered physician with knowledge of substance misuse.

You can request a re-test. You will not be permitted to provide a new specimen; instead, the secondary B sample taken at the time of donation will be tested in another laboratory to confirm or refute the first positive report. You will normally have to pay for this re-test. B samples are transferred directly between laboratories and are not returned to the individual.

That depends on your company and its policies and procedures. However, company policies usually facilitate treatment and encourage self-referral.

Usually not. However, if you dispute a test and request a re-test in another laboratory, you will normally be expected to pay for it.

Urine alcohol and drug testing is well established — since the 1980s many millions of specimens have been collected worldwide and much research has taken place. Oral fluid testing is now increasing in popularity due to its ease of collection and donor acceptance, with established guidelines for practice.

For health and safety reasons, blood sampling is not recommended for workplace testing. Breath testing is the primary means of detecting alcohol — the technology is well established and the principles are enshrined within drink-drive legislation. For drugs, oral fluid testing is an attractive alternative to urine and is now mainstream in many circumstances.

Hair testing is appropriate when retrospective drug abuse is to be detected. Drugs become incorporated into growing hair, and as scalp hair grows at about 1 cm per month, a proximal 3 cm length represents roughly a 3-month retrospective period. Hair testing reflects use over the entire growth period and is unlikely to detect occasional or low-level use. Hair analysis can also help in the assessment of alcohol consumption.

The presence of drugs in oral fluid is related to their concentration in blood, although they can also arise from residual drug remaining in the mouth. Because drugs persist in oral fluid for a shorter time than in urine, their presence is more likely to reflect recent use. A drug concentration cannot on its own establish impairment.

Collection is non-invasive, easy, fast and requires minimal facilities. Sampling is always in sight of the collector, making adulteration difficult. Samples can be taken quickly following an incident, and no toilet facilities are necessary. Oral fluid testing is more likely to reflect recent use, which can help employers show they are using the least intrusive test relevant to safety, as the ICO expects.

Drugs which are smoked, inhaled or taken orally appear immediately after use because of mouth contamination. Drugs administered orally in capsules do not contaminate the oral cavity. Drugs administered intravenously are detected in oral fluid about 10 minutes after injection.

Yes. As with urine, international guidelines are available for the collection and analysis of samples, and laboratories should be accredited for oral fluid analysis.

Screening can be carried out using inexpensive manual devices (such as the Dräger DrugCheck 3000) as well as sophisticated automated electronic devices such as the Dräger DT5000. The choice of device depends largely on budget.

It is possible, but cutoff levels are likely to exclude all but the most extreme conditions.

Yes, a second sample is normally taken and kept sealed.

Oral fluid collection devices contain a visual sample volume indicator, which shows that sufficient sample has been collected.

Apart from physical disability or injury, the vast majority of individuals can provide a sufficient sample. Dry mouth conditions are occasionally encountered due to nervousness or stress; however, they can also be caused by drug use.

Yes. A period of at least 15 minutes is usual for workplace collection. It is important that there is nothing in the mouth during that time, such as food, drink, gum or smoking.

Usually yes, but this will depend upon the company substance abuse policy.

Yes.

Yes, the software in the DT5000 allows for retrospective data access.

No. Once calibration has expired the device should not be used for any result that may be relied on. Have it recalibrated first.

A period of at least 15 minutes must elapse before a breath sample is taken. This allows any mouth alcohol — residue remaining after the last alcoholic drink — to disperse.

Yes. Positive screening tests must be followed up with confirmation testing in the laboratory. Confirmatory testing identifies exactly which substance is present, and a confirmed prescribed drug is reviewed against declared medication.

No, it is not essential to carry out a drug screening test if alcohol alone is suspected.

This is routine practice. The lower of the two results is taken as the final result. Duplicate sampling enhances the quantitative certainty of the test and can detect anomalies such as mouth alcohol arising from regurgitation.