The advantages of narrow-window and wide-window drug testing for legal matters

Gail Evans, Alphabiolabs

By Gail Evans, Technical Trainer at AlphaBiolabs
Last reviewed: 30/05/2024

When it comes to drug testing for legal matters, the most common test methods are urine, oral fluid, nails and hair. Urine and oral fluid (saliva) testing are ideal for regular testing because they are quick, accurate and provide immediate screening results. As such, these tests are known as ‘narrow-window’ forms of testing: their period of detection is from 30 minutes after ingestion up to a few days, although this can depend on the particular substance taken. Hair or nails drug testing is particularly useful to gain a more comprehensive overview of a person’s drug use. These types are known as ‘wide window’ forms of testing, which can determine a history of drug intake for up to 12 months

Both narrow-window and wide-window testing can be used to produce court-admissible results and by using both together, social workers, legal professionals and local authorities can gain a much more detailed, accurate picture of an individual’s long-term and short-term drug use.

Table of contents
  • Narrow-window testing
  • Wide-window testing
  • Where can I get testing from for legal matters?

Narrow-window testing

Urine drug tests and oral fluid/saliva drug tests provide a narrow window of detection.

This means that each test can only tell us whether an individual has been using drugs in the few days prior to the samples being collected.

A urine drug test provides a window of detection of up to four days.

An oral fluid (saliva) drug test provides a window of detection up to 48 hours.

The narrower detection window means that these types of testing are ideal for regular use at pre-proceedings stage – for example, where a parent has sole custody of the child(ren) over a weekend or after planned child visits. Regular use of narrow window testing can complement hair or nail drug testing (which provide details of historic drug use) to potentially prevent the case moving into full care proceedings.

The testing can be done regularly via our UK-wide network of professional sample collectors or at one of our nationwide walk-in centres and, because it is carried out following strict chain of custody requirements, a court-approved report is also available if required. This is helpful if the case does eventually move to the care proceedings stage.

With both types of narrow-window testing, if the results are non-negative, the samples need to be sent to our UKAS ISO 17025 accredited laboratory for quantitative tests to determine exactly which drugs are present and in what quantity.

Urine Testing

AlphaBiolabs’ urine drug testing can test for 14 drugs and their metabolites: amphetamine, barbiturates, benzodiazepines, buprenorphine, cannabis, cocaine, ecstasy (MDMA), ketamine, methadone, methamphetamine, opiates, phencyclidine (PCP), propoxyphene and tramadol. Most drugs are flushed out of the body in a matter of days. Drugs including cocaine, MDMA and methamphetamine can be present in urine for roughly 4 days, but cannabis can stay in urine for as long as 28 days after chronic use.

AlphaBiolabs’ sample collectors follow strict procedures to ensure that chain of custody is maintained, and that confidentiality remains throughout the whole testing process. The drug screening kit has test strips built in to reduce urine handling, as well as tamper protection features to help ensure integrity of the sample.

The presence of a line or lines indicates a negative result for the corresponding drug.

Where no lines appear at the Test line, and only the band appears at the Control line, this indicates a reaction for the corresponding drug (a non-negative result).

For a non-negative result, the trained sample collector will transfer the urine sample in equal quantities into two separate containers, representing an A sample and a B sample. Each container is then sealed with tamper tape to ensure chain of custody is maintained.

Both urine samples (A and B) are then safely transported back to our UKAS ISO 17025 accredited laboratory for in-depth analysis, and confirmation of the results.

Oral Fluid (Saliva) Testing

Oral fluid testing can detect drugs from as quickly as 30–60 minutes after ingestion up to 48 hours afterwards, although this can depend on the particular substance taken.

An oral fluid (saliva) drug test provides results in minutes, using a self-contained screening unit that can detect a variety of drugs and their metabolites including methamphetamines, opiates, cocaine, cannabis, amphetamines and benzodiazepines. It is ideal for regular testing because it can be performed on site quicky and easily, and without the need for dedicated collection facilities.

Typically, the oral fluid device consists of two components: an absorbent sample collector pad for obtaining a saliva sample, and a test cassette for the analysis (depending on the device being used).

The test cassette includes a detection window with two test strips, which displays the Control and Test lines.

Once the collector has taken the donor’s sample using the absorbent pad, it is then inserted back into the test cassette for analysis.

If the test result is negative, a line will appear alongside the respective substance class (drug). This means that none of the substance was detected in the sample.

If no line appears next to the substance class, this means that the substance was detected in the sample, indicating a non-negative result.

For a non-negative test result, a further two oral fluid/saliva samples must be collected for laboratory testing. Both samples are then returned to our UKAS-accredited toxicology laboratory for in-depth analysis and confirmation of the test result.

Wide-window testing

When a person consumes drugs, they are broken down by the liver and a proportion of the parent drug and its metabolites are released into the bloodstream, with a small amount being excreted by the body in a variety of ways.

Whereas urine and oral fluid (saliva) drug testing methods provide us with a ‘narrow-window’ of detection for drug use (from a few hours up to a few days), hair drug tests and nail drug tests offer what is known as a ‘wide-window’ of detection (up to 12 months).

This is due to the way in which drugs are retained in the hair and nails long after substances were first consumed. Unlike oral fluid or urine testing, hair and nail drug testing results are only available after analysis at the laboratory.

Hair drug testing

A hair drug test can provide an insight into historic drug use for up to 12 months after drugs were first consumed (depending on the length of hair available).

After ingesting a drug, it is absorbed into the bloodstream. Drugs and their metabolites are then transported through the root of the hair and become embedded in the hair shaft. These metabolites remain in the hair as it grows, hence it is a suitable method for detecting a person’s historical drug intake on a month-by-month basis. Unlike urine and oral fluid tests, hair strand analysis cannot show recent drug history, as it can take between 7–10 days for the hair containing the drug to grow above the scalp.

The advantage of hair drug testing is that drugs remain relatively stable in hair and can thus be stored indefinitely. This wide-window test can effectively confirm long-term exposure to drugs over a defined period depending on the length of hair collected (from 1 month up to 12 months – if sufficient hair is available).

Hair drug testing is commonly used during care proceedings and it is particularly useful to gain a more comprehensive overview of a person’s drug use. Hair can be sectioned for segmented analysis, which is a month-by-month view of drug intake. Alternatively, an overview analysis can determine historic drug intake.

Drugs routinely tested for include amphetamine, benzodiazepines, buprenorphine, cannabis, cocaine, ecstasy (MDMA), ketamine, mephedrone, methadone, methamphetamine, opiates, phencyclidine (PCP) and zolpidem. Hair drug testing can also be arranged for GHB, LSD, spice, steroids, tramadol and other less common drugs.

Nail Drug Testing

Nail drug testing is an extremely reliable and effective method for identifying historic drug use.

In nails, a proportion of the parent drug and its metabolites finds its way to the nail bed, becoming trapped in the keratin fibres along the entire length of the nail.

A nail drug test can also provide an insight into drug use for the period prior to samples being collected (overview of up to 12 months).

Either fingernail clippings or toenail clippings can be used for nail drug testing, however the two sample types cannot be mixed at the laboratory. This is because fingernails and toenails grow at different rates, with each offering differing insight into drug use – an overview of up to six months for fingernails, and an overview of up to 12 months for toenails.

Unlike head hair, which can be segmented to provide a month-by-month insight into drug use (depending on the length of hair available), nail clippings cannot be segmented. This means that only an overview of drug use can be provided for the period prior to samples being collected (up to 12 months).

Any artificial nail applications including acrylics, gels, polish, and nail extensions must also be completely removed prior to testing, so as not to impact the results.

Summary: Oral Fluid Testing
Advantages Disadvantage Legal application
Narrow window of detection: 30-60 minutes after ingestion up to 48 hours Small detection window – will not pick up any drugs that were consumed historically Ideal when it is suspected that someone might be under the influence of drugs in the ‘here and now’
On-site screening with indicative results available on site and confirmation testing at the laboratory Tests for a smaller panel of drugs than other methods of testing Ideal for regular testing at pre-proceedings stage of family protection / child custody cases
Can ascertain recent drug use so ideal for monitoring day-to-day drug usage Screen & confirmation for 6 of the most used drugs -methamphetamines, opiates, cocaine, cannabis, amphetamines, benzodiazepines
Low cost
Sample easy to collect, hygienic and non-invasive
Apparatus is compact and can be used anywhere
Summary: Urine Testing
Advantages Disadvantage Legal application
Narrow window of detection: most drugs up to 4 days Small detection window – will not pick up any drugs that were consumed historically Ideal when it is suspected that someone might be under the influence of drugs in the ‘here and now’
On-site screening with indicative results available on site and confirmation testing at the laboratory Needs dedicated toilet facility for the collection Ideal for regular testing at pre-proceedings stage of family protection / child custody cases
Can ascertain recent drug use Donor may not be able to produce enough urine Screen & confirmation for a wide variety of commonly used drugs
Ideal for monitoring day-to-day drug usage Done out of sight of collector – more opportunity for donor to attempt to tamper with sample
Low cost
Tamper-prevention features protect against ‘fake ‘samples
Summary: Hair Testing
Advantages Disadvantage Legal application
Wide window of detection: 1 month up to 1 year Cannot determine recent drug use Head hair can be used to create month-by-month profiles, to determine a detailed pattern of drug usage.
Most accurate testing method for giving an overview of an individual’s drug use Most expensive testing method Drug Screen Plus service can tell you whether any additional substances were present in the sample that you didn’t specifically ask us to test for
Can determine historic drug use via segmented or overview analysis

 

Results are not immediate – must be processed by the laboratory Test results are accepted by Family Courts and the Child Maintenance Service
Can test for the widest variety of drugs
Impossible to ‘cheat’ a hair drug test
Summary: Nail Testing
Advantages Disadvantage Legal application
Wide window of detection: 6 months up to 1 year Cannot determine recent drug use Ideal where hair testing is not possible (e.g. when donor has little or no hair or cannot provide a hair sample for religious reasons)
Simple, non-invasive method of testing Can only provide an overview of drug use, not a month-by month analysis Test results are accepted by Family Courts and the Child Maintenance Service
Can determine historic drug use via overview analysis (6 months fingernails, 12 months toenails) Results are not immediate – must be processed by the laboratory
Can test for wide variety of drugs and their metabolites Artificial nail applications including acrylics, gels, polish, and nail extensions must be completely removed prior to testing

Where can I get testing from for legal matters?

AlphaBiolabs has extensive experience providing drug testing services for local authorities, family law professionals and social workers. We have also invested in the very latest technology for our state-of-the-art UKAS ISO 17025 accredited laboratory, so you can be confident of receiving a 100% accurate result.

We have a UK-wide network of professional sample collectors, and all sample collections are performed under strict chain of custody conditions.

We also offer FREE sample collection for legally-instructed drug tests from any of our nationwide walk-in centres.

For expert advice on which testing method is best for your client, or to request a quote, call AlphaBiolabs’ Legal team on 0333 600 1300 or email testing@alphabiolabs.com.

Alternatively, complete our online quote form, and a member of the team will be in touch to discuss your needs.

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Gail Evans, AlphaBiolabs

Gail Evans

Technical Trainer at AlphaBiolabs

A professionally-trained forensic scientist, Gail joined AlphaBiolabs in 2012 and holds the role of Technical Trainer.

Her day-to-day responsibilities include delivering in-depth training sessions both internally and externally, covering DNA, drug, and alcohol testing.

Throughout her career at AlphaBiolabs, Gail has held a variety of roles, including within the Legal and Workplace sectors of the business.

Before joining the company, Gail was a practicing forensic scientist with 25 years’ experience working for the Forensic Science Service, attending scenes of crime, and analysing physical and biological material with potential evidential value.