The differences between urine and oral fluid (saliva) drug testing

In this article, we explore urine versus oral fluid (saliva) drug testing, the benefits of each type for legal purposes and what the results can determine about an individual’s pattern of drug use.

How can drugs be detected in urine and oral fluid (saliva)?

When a person consumes drugs, they are broken down by the liver, and a proportion of the drug and its metabolites are released into the bloodstream, whilst some of the drug is excreted from the body in a variety of ways, including though urine and saliva.

This makes it possible to analyse a variety of samples and determine whether drugs and their metabolites are present in hair, nails, oral fluid (saliva) and urine. 

A small, self-contained screening device such as a urine sample pot or an oral fluid device can be used to detect these substances in a person’s urine or saliva.

Unlike hair drug testing and nail drug testing, urine drug tests and oral fluid/saliva drug tests provide what is known as a ‘narrow-window’ of detection.

This means both tests can detect substances for a short period of time (a few days) from when the person initially consumed drugs.

When are oral fluid and/or urine drug tests performed?

AlphaBiolabs works with many family law firms, legal practitioners, courts and local authorities to support decisions that protect children and families from the effects of harmful substances. Oral fluid or urine drug testing is most-commonly performed during the pre-proceedings stage of a family protection / child custody case.

A trained sample collector will take an initial sample and this will be immediately screened for the drugs in the panel (usually six drugs in oral fluid or fourteen drugs in urine). This can be done as a stand-alone collection or when collecting other sample types such as hair or nails (which provide an overview of up to 12 months of drug use).

A negative screening result for either urine or oral fluid will conclude the testing there and then.

A non-negative screening result will lead to two further samples being taken (A and B), which are then sent to our UKAS-accredited toxicology laboratory for more comprehensive confirmation testing.

What is the difference between a urine drug test and an oral fluid (saliva) drug test?

Both urine drug tests and oral fluid (saliva) drug tests provide a quick, simple, and non-invasive way to find out whether a person has recently consumed drugs.

However, there are a couple of fundamental differences between the two tests.

The most obvious difference is the type of sample used to test for the presence of drugs, with a urine drug test requiring a urine sample, and an oral fluid drug test requiring a sample of the individual’s saliva.

The other key difference is the detection window for each test i.e. the period during which drugs can be detected in a urine or saliva sample. See How long does it take for drugs to be detected in urine and oral fluid?

However, the procedure surrounding the sample collection process is the same for each test.

This means that samples collected for urine and oral fluid/saliva drug tests collected during pre-proceedings are always done under strict chain of custody conditions.

This reduces the likelihood of samples being tampered with, ensures samples are collected from the right people, and means that the test results are legally admissible.

All non-negative test samples for either urine oral fluid drug tests are also subject to stringent analysis by our expert team in our in-house toxicology laboratory, to provide final confirmation of the results.

How is a urine drug test performed?

During a urine drug test, the donor will be asked to provide a urine sample using a fully self-contained urine screening kit that can detect the presence of certain drugs in a donor’s urine sample.

Prior to sample collection, the trained sample collector will prepare a suitable toilet for the donor to use while collecting their sample, taking careful measures to prepare the area, the toilet, and the washing facilities to reduce the possibility of the sample being tampered with.

The donor will then collect their urine sample in private.

Once testing is completed, the sample collector will look at the test strips on the side of the pot to assess whether any substances were detected or not.

For a negative result, coloured lines will appear on the test strips indicating that none of the substances were detected in the sample.

For a non-negative result, no coloured lines will appear on the test strips for the corresponding drug. This indicates that the substance has been detected.

The urine sample will then be returned to AlphaBiolabs’ state-of-the-art toxicology laboratory so that a more in-depth analysis can be performed, and the result can be confirmed.

How is an oral fluid (saliva) drug test performed?

An oral fluid (or saliva) drug test is performed by using a self-contained oral fluid device to take a sample of a person’s saliva.

One of our trained collectors will take an initial sample, which will be immediately screened for the drugs in the panel. This can be done as a stand-alone collection or when collecting other sample types such as hair or nails.

The sample collector will prepare the oral fluid testing device.  This is equipped with an absorbent sample pad that is rubbed around the inside of the sample donor’s mouth to collect saliva for testing, and a test cassette for analysis (depending on the device that is being used for the test).

Once the sample has been taken from the donor, the sample collector will put the absorbent pad into the test cassette.

For a negative result, a line will appear next to each of the substance classes on the device, indicating that no substances were detected in the sample. A negative screening result will conclude the oral fluid testing there and then.

For a non-negative result, a line will fail to appear next to one or more of the substance classes on the device. This indicates that the corresponding substance was detected in the saliva sample.

If the test returns a non-negative result, two further saliva samples will be taken by the sample collector and returned to AlphaBiolabs’ state-of-the-art toxicology laboratory for in-depth analysis, so that the result can be confirmed.

How long does it take for drugs to be detected in urine and saliva?

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 tests 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.

Where the court requires a historic overview of drug use, nail drug testing or hair drug testing can provide a ‘wide window’ of detection (up to 12 months for head hair and up to 12 months for nails).

Learn more about hair and nail drug testing.

How long does it take to get the results of a urine drug test?

An AlphaBiolabs urine drug test provides results in minutes, using a self-contained screening unit that can detect up to 10 different drugs.

The drug screening kit has test strips built in to reduce urine handling.

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 a line 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 the laboratory for in-depth analysis, and confirmation of the results.

AlphaBiolabs provides fast confirmations with results available within 7 days from sample receipt into our in-house, UKAS-accredited toxicology laboratory.

How long does it take to get the results of an oral fluid (saliva) drug test?

An AlphaBiolabs 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.

Typically, the oral fluid device consists of two components: an absorbent sample collector 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 the toxicology laboratory for in-depth analysis and confirmation of the test result.

AlphaBiolabs provides fast confirmations with results available within 7 days from sample receipt into our in-house, UKAS-accredited laboratory.

How accurate are oral fluid (saliva) and urine drug tests?

Both urine drug tests and oral fluid (saliva) drug tests are extremely accurate and reliable, based on the sample provided by the donor at the time of collection.

Our sample collectors follow strict procedures throughout the collection process to ensure that chain of custody is maintained and results are legally admissible.

This includes confirming the identity of the sample donor by checking acceptable photographic ID such as a passport or driving licence.

Tamper tape is also used to secure non-negative samples before they are returned to the laboratory for confirmation testing.

The addition of this laboratory confirmation provides further reassurance that all drug tests results are 100% reliable, and that the findings are accurate. Furthermore, detailed laboratory analysis removes any doubt whatsoever about which substances were detected.

Each of these steps helps ensure that pre-proceedings results are defensible, whichever method of testing you choose.

Which drug test is better – urine or oral fluid (saliva)?

Thanks to advances in modern toxicology testing, both urine drug tests and oral fluid/saliva drug tests are extremely accurate and reliable, based on the sample provided at the time of collection.

The self-contained testing kits used for urine and oral fluid (saliva) screening are both extremely sensitive, detecting trace amounts of substances in the donor’s sample.

Social workers or family law professionals who are considering ordering testing at pre-proceedings stage should consider the benefits of each of test, and how each test might suit the needs of their case.

For example, oral fluid/saliva drug testing can be useful if there isn’t anywhere suitably private for the donor to collect a urine sample, or if a urine sample cannot be provided for another reason. Oral fluid testing is hygienic, discreet and cheat proof, as the sample collector collects it directly.

Oral fluid drug testing has become increasingly popular as it is a discreet, non-invasive way to carry out drug testing. Some donors may also feel more comfortable providing a saliva sample, than they would providing a urine sample for testing.

However, an oral fluid/saliva drug test can only provide a window of detection of up to 48 hours after drugs have been consumed.

Urine drug testing is a highly accurate and well-established method of testing for drug use, providing a wider window of detection than oral fluid drug tests (up to four days).

Both urine drug tests and oral fluid drug tests can be used to complement hair or nail drug testing, which provide a wider window of detection (or up to 12 months) and can indicate historic use.

Where can I get a urine or oral fluid drug test?

AlphaBiolabs has extensive experience providing drug testing services for local authorities, family law professionals and social workers. We have invested in the very latest technology for our state-of-the-art toxicology laboratory, employing the best scientists, so you can be confident of receiving an 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.