Saliva Drug Testing: How Accurate Are They?

Drug and alcohol testing has become a standard safety measure across Australia — not just in high-risk industries like mining, transport, and construction, but also in schools, sporting clubs, and even at home. As workplaces and communities continue to prioritise safety, compliance, and early detection, the need for fast and reliable screening tools has never been more important.

This is where saliva drug test kits stand out. Unlike laboratory tests that require specialised collection procedures and longer processing times, saliva testing offers a non-invasive, quick, and highly practical alternative. Results are available in minutes, collection is easy to supervise, and the process is far less intrusive than urine or blood testing. That’s why saliva drug tests are now widely used for:

• Pre-employment and workplace compliance
  
• Post-incident or reasonable-cause screening
  
• Random testing programs
  
• School, sports club, and community-based safety initiatives
  
• At-home or parental monitoring

In this guide, we’ll break down — in simple, clear terms — how saliva drug test kits work, how accurate they are, the types of substances they detect, and the features you should look for when choosing one.

We’ll also highlight the Screenclear S8 Saliva Drug Test Kit, a trusted, workplace-ready device designed to meet Australian testing standards.

What is a drug test kit? (and what is it used for?)

A drug test kit is a screening tool used to detect the presence of drugs or alcohol in a person’s system. These kits provide quick, on-the-spot results and are commonly used when decisions need to be made immediately — such as in workplaces, safety-critical environments (including healthcare), and post-incident situations.

While laboratories can run more detailed confirmatory tests, on-site drug test kits are designed for initial screening. They help identify whether a person may have recently used a substance and whether further steps (like medical assessment or lab confirmation) are needed.

Where drug test kits are commonly used

Drug test kits serve many purposes across different settings, including:

• Workplace compliance programs — ensuring employees are fit for duty
  
• Reasonable-cause testing — when impairment is suspected
  
• Post-incident testing — after accidents, near misses, or safety breaches
  
• Random testing initiatives — maintaining a safe work environment
  
• At-home or parental testing — for personal reassurance or monitoring
  
• Schools, sporting clubs, and community programs — supporting wellbeing and safety

Screening vs laboratory confirmation

It’s important to understand the difference:

• On-site testing (saliva or urine kits) - Provides preliminary or presumptive results. These are fast and cost-effective but not legally binding on their own.
  
• Laboratory testing - Provides confirmatory results using advanced analytical techniques (such as GC-MS). These tests determine with certainty whether a substance is present and at what level.

Types of drug testing: Saliva vs urine vs blood tests

There are three main types of drug testing used today. Each one detects substances differently, offers different time windows, and is suited to different situations.

Saliva (oral fluid) testing

Saliva testing is one of the most widely used methods for fast, on-site screening — especially in workplaces.

How it works:

A swab collects oral fluid from the cheeks, gums, or under the tongue. The device then analyses the sample for traces of recent drug use.

Strengths of saliva testing:

• Detects recent drug use (typically within the last few hours up to around 24 hours, depending on the drug)
  
• Non-invasive and comfortable for the person being tested
  
• Much harder to tamper with compared to urine samples
  
• Very quick — results are ready in minutes
  
• Ideal for workplace, roadside, and post-incident screening

Because saliva tests show what’s happening right now, they’re excellent for assessing current impairment risk.

Urine testing

Urine tests are another common method, but they serve a different purpose than saliva.

How it works: 

A urine sample is collected and either tested on-site or sent to a laboratory.

Key characteristics:

• Detects drug use over a longer detection window (days to weeks depending on the substance)
  
• More invasive, requiring private collection areas
  
• Higher risk of sample tampering or substitution
• Not as useful for assessing immediate impairment
  
• Better suited for ongoing monitoring or compliance programs

Urine testing focuses more on historical drug use rather than what’s happening at the time of testing.

Blood testing

Blood tests are rarely used outside medical or forensic settings, but they provide the highest level of accuracy.

How it works:

A trained clinician collects a blood sample and sends it to a laboratory for analysis.

Why blood tests are used:

• Most accurate test for detecting current intoxication
  
• Measures the exact concentration of substances in the body
  
• Essential in medical, legal, or coroner investigations
  
• Higher cost and slower turnaround
  
• Requires specialised personnel and equipment

Blood testing is the gold standard for legal or medical confirmation, but it’s not practical for everyday workplace screening.

How do saliva drug test kits work in general?

Saliva drug testing may seem technical, but the process behind it is actually quite simple. These kits are designed to give fast, reliable results by detecting drug metabolites — the chemical traces left behind after a substance is used — in a person’s oral fluid.

Here’s a breakdown of how the process works:

1. Collecting the saliva sample

A swab is used to gather oral fluid from the cheeks, gums, and underneath the tongue. These areas tend to hold higher concentrations of drug metabolites, which helps improve test accuracy.

2. The sample activates the test device

Once the swab has collected enough fluid, it’s inserted into the testing device. Inside the device are test strips coated with specific reagents (chemical indicators).

When the saliva reaches these strips:

• Drug metabolites (if present) bind to the reagents.
  
• This chemical reaction produces a visible result on the test window.

3. Results appear in minutes

Most saliva drug tests — including the Screenclear S8 at Aussie Pharma Direct— generate results quickly, typically within a few minutes.

The device will show one of three outcomes:

• Negative: No drugs detected.
  
• Presumptive Positive: Drug metabolites are present.
  
• Invalid: Not enough saliva or an error occurred during testing.

4. What “cut-off levels” mean

Saliva tests are designed with cut-off levels, which indicate the minimum amount of a drug metabolite needed for the test to register a positive result.

Think of it as a built-in threshold:

• If the amount is below the cut-off → the result is negative
  
• If it’s above the cut-off → the result is presumptive positive

Cut-off levels are important because they help avoid false positives from trace environmental exposure and ensure the test reflects recent, meaningful drug use.

Why saliva testing is so fast and practical

Because metabolites enter saliva quickly after drug use, saliva testing:

• Works well for detecting recent drug use
  
• Reduces the risk of tampering compared to urine tests
  
• Is simple enough to use on-site without lab equipment
  
• Provides quick decision-making in workplaces and safety-sensitive roles

Are saliva drug test kits accurate?

Yes — when used correctly, saliva drug test kits are highly accurate for detecting recent drug use, which is why they are widely used in workplaces, roadside testing, and compliance programs across Australia.

What makes saliva testing reliable?

Saliva drug test kits are designed to meet strict performance standards. High-quality devices undergo thorough laboratory testing to demonstrate:

• Sensitivity — their ability to detect even small amounts of a drug metabolite
  
• Specificity — their ability to detect only the target drug and avoid cross-reactivity
  
• Reproducibility — consistent results across multiple tests
  
• Accuracy — a combination of sensitivity, specificity and overall reliability

Cut-off levels: How they improve accuracy

As mentioned before, every saliva drug test kit uses cut-off levels, which act as thresholds to determine whether a substance is present in meaningful amounts.

These levels:

• Prevent false positives from trace or environmental exposure
  
• Ensure the test reflects actual use, not incidental contact
  
• Standardise results across different test brands

For example, minute amounts of cannabis detected from passive smoke would fall below the cut-off and therefore not trigger a positive result.

When accuracy may be affected

Several factors can influence saliva test performance:

• Insufficient saliva collected
  
• Eating, drinking or smoking shortly before the test
  
• Incorrect timing (testing too soon or too late after use)
  
• Improper storage of kits
  
• Expired kits
  
• Poor swab contact with oral surfaces

Following the instructions closely — especially with sample collection — is key to ensuring an accurate result.

What test kits can and cannot tell you

Saliva drug tests are excellent screening tools, but like all point-of-care tests, they have limitations.

They CAN:

• Indicate recent drug use (typically within hours)
  
• Support workplace decisions about fitness for duty
  
• Help guide whether a follow-up laboratory test is needed

They CANNOT:

• Determine exact drug concentration
  
• Identify long-term or historical drug use
  
• Act as a legally binding final result on their own

A “presumptive positive” on a saliva test is usually followed by a confirmatory laboratory analysis (e.g., GC-MS) to verify the result.

Screenclear S8 Saliva Drug Test Kit at Aussie Pharma Direct

At Aussie Pharma Direct, we stock the Screenclear S8 because it provides reliable on-site testing, meets quality expectations for Australian workplaces, and is suitable for both professional and personal use.

The Screenclear S8 is a dependable, easy-to-use saliva drug test kit designed for workplaces, healthcare settings, community programs, and home users who need fast, accurate results. Known for its simple collection method and clear readout window, the S8 offers a practical solution for screening recent drug use.

What the Screenclear S8 Saliva Drug Test Kit detects

The Screenclear S8 is a multi-substance saliva drug test designed to detect a wide range of commonly misused drugs. It is verified to AS4760:2019, meaning it meets the strict Australian standards for workplace saliva drug testing.

Here are the drug classes it detects, along with their cut-off levels:

1. Delta9-THC (Marijuana / Cannabis)

• Cut-off: 15 ng/mL

2. Methamphetamine

• Cut-off: 50 ng/mL

3. Amphetamines

• Cut-off: 50 ng/mL
• Includes substances such as dexamphetamine.

4. Opiates

• Cut-off: 50 ng/mL
• Detects drugs such as morphine and codeine.

5. Cocaine

• Cut-off: 50 ng/mL

6. Benzodiazepines

• Cut-off: 10 ng/mL
• Covers sedatives like diazepam, temazepam, or alprazolam.

7. Oxycodone

• Cut-off: 40 ng/mL

8. Alcohol (via colour chart)

• Range: 0.02 to 0.300

Why choose the Screenclear S8 Saliva Drug Test Kit?

Saliva drug testing has become one of the most trusted ways for workplaces, schools, and safety-critical industries to screen for recent drug use quickly and efficiently. It offers the ideal balance of speed, accuracy, and convenience, allowing organisations to make informed decisions without the delays or complexity of lab-based testing.

When choosing a saliva drug test kit, reliability matters — and that’s what the Screenclear S8 Saliva Drug Test Kit offers. Designed specifically for Australian workplaces, it delivers everything a modern safety program needs:

• ✔ Fully compliant with AS4760:2019, ensuring your testing procedure meets national standards
• ✔ Multi-drug detection, covering the most commonly encountered substances
• ✔ Workplace readiness, with fast on-site results that support immediate action
• ✔ Cost-effective screening, reducing the need for expensive laboratory testing
• ✔ Easy training and implementation, thanks to its simple, non-invasive collection process

Order the Screenclear S8 Drug Test Kit Today