What Drugs Are Tested for in a Workplace Drug Test?
The standard Australian workplace drug test screens for five drug classes under AS/NZS 4308. Here is exactly what is tested, how long each substance is detectable, and what happens with prescription medications.
The Standard Australian Drug Testing Panel
Workplace drug testing in Australia follows AS/NZS 4308:2008 (Procedures for specimen collection and the detection and quantitation of drugs of abuse in urine). This standard defines the drug classes that are included in the standard screening panel used for workplace testing.
The standard panel tests for five drug classes. These are the substances most commonly associated with workplace impairment and safety risk. Every workplace drug test conducted under AS/NZS 4308 screens for these five classes as a minimum.
Amphetamines (including Methamphetamine and MDMA)
This class covers amphetamine, methamphetamine (speed, ice, crystal meth), and MDMA (ecstasy). These are stimulant drugs that can cause impaired judgement, erratic behaviour, fatigue after use, and increased risk-taking. Methamphetamine is one of the most commonly detected substances in Australian workplace drug testing. The screening threshold under AS/NZS 4308 is 300 micrograms per litre for urine.
Cannabis (THC)
Cannabis testing detects THC (delta-9-tetrahydrocannabinol), the psychoactive compound in marijuana. Cannabis can impair reaction time, coordination, and decision-making. It is the most commonly used illicit substance in Australia. The screening threshold under AS/NZS 4308 is 50 micrograms per litre for urine. Cannabis has the longest detection window of the standard panel drugs in urine, which is an important consideration for both employers and employees.
Cocaine
Cocaine is a stimulant that causes short-term euphoria followed by fatigue, irritability, and impaired judgement. While less commonly detected than amphetamines or cannabis in Australian workplace testing, it is included in the standard panel. The screening threshold under AS/NZS 4308 is 300 micrograms per litre for urine. Detection in urine typically occurs for 2 to 4 days after use.
Opiates (including Morphine, Codeine, and Heroin)
This class covers morphine, codeine, heroin (which metabolises to morphine), and other opiate-based substances. Opiates cause drowsiness, impaired concentration, and slowed reaction times. The screening threshold under AS/NZS 4308 is 300 micrograms per litre for urine. Some prescription pain medications contain codeine, which is relevant for employees declaring prescribed medications before testing.
Benzodiazepines
Benzodiazepines include diazepam (Valium), oxazepam, temazepam, and alprazolam (Xanax). These are sedative medications commonly prescribed for anxiety and sleep disorders. They cause drowsiness, impaired coordination, and slowed reaction times. The screening threshold under AS/NZS 4308 is 200 micrograms per litre for urine. Because benzodiazepines are commonly prescribed, employees should be given the opportunity to declare any current prescriptions before testing.
Extended Drug Panels
Some employers request testing beyond the standard five-drug panel. Extended panels are not required by AS/NZS 4308 but can be added based on the employer's risk assessment and policy.
Common additions to the standard panel include synthetic cannabinoids (also known as synthetic cannabis or "spice"), oxycodone (a synthetic opioid not detected by the standard opiate screen), fentanyl, buprenorphine (Subutex/Suboxone), and tramadol. Some employers in high-risk industries also test for ketamine or methadone.
Extended panels increase the cost of testing because each additional substance requires separate screening and confirmation. Employers should consider whether the additional substances are relevant to their workplace risk profile before adding them to the testing regime.
Note on alcohol: Alcohol is not part of the AS/NZS 4308 drug panel because it is tested separately using a breath test (breathalyser). Most workplace drug and alcohol testing programs include both a drug screen (urine or saliva) and a breath alcohol test as separate components of the same session.
Detection Windows: Urine vs Saliva
How long a substance is detectable depends on the testing method. Urine testing and saliva (oral fluid) testing have different detection windows, and this difference matters when choosing which method to use.
Urine Detection Windows
Urine testing detects drug metabolites that the body produces as it processes the substance. Because metabolites take time to form and are cleared slowly, urine testing has a longer detection window. Typical windows: Cannabis - 3 to 30 days depending on frequency of use (occasional use 3-5 days, regular use up to 30 days). Amphetamines/methamphetamine - 2 to 4 days. Cocaine - 2 to 4 days. Opiates - 2 to 3 days. Benzodiazepines - 3 to 7 days for short-acting, up to 30 days for long-acting types at therapeutic doses.
Saliva (Oral Fluid) Detection Windows
Saliva testing detects the parent drug rather than metabolites, so the detection window is shorter and more closely aligned with recent use and potential impairment. Typical windows: Cannabis - up to 24 hours. Amphetamines/methamphetamine - up to 48 hours. Cocaine - up to 24 hours. Opiates - up to 48 hours. Benzodiazepines - detection in saliva is less reliable than urine for some benzodiazepines, with windows varying from a few hours to 2-3 days depending on the specific drug.
These detection windows are approximate and vary depending on the individual's metabolism, the amount used, frequency of use, and other factors. They should be used as a general guide rather than precise cut-offs.
Prescription Medication Considerations
Several prescription medications can produce a positive result on a workplace drug test. This does not mean the employee has done anything wrong - it means the testing process needs to account for legitimate prescribed use.
The most common prescription medications that can cause positive results include codeine-containing pain medications (detected as opiates), benzodiazepines prescribed for anxiety or sleep disorders, dexamphetamine prescribed for ADHD (detected as amphetamines), and some cold and flu medications containing pseudoephedrine (which can cross-react on amphetamine screens).
A well-run testing program handles this by giving the employee the opportunity to declare any prescription medications before the sample is collected. If a positive result occurs for a declared medication, and the employee can provide evidence of a valid prescription, the result is typically not treated as a policy breach. However, the employer may still need to assess whether the medication affects the employee's fitness for duty in their specific role, particularly if the role is safety-critical.
Employee health information, including declared medications, must be handled in accordance with the Privacy Act 1988 and relevant state health records legislation. This information should only be disclosed on a need-to-know basis and stored securely.
The Confirmatory Testing Process
Workplace drug testing is a two-stage process: initial screening followed by confirmatory testing if the screen is non-negative.
Initial screening
The first test uses an immunoassay-based screening device (either a urine cup with built-in test strips or an oral fluid device). This produces a result within minutes - either negative or non-negative (sometimes called a "preliminary positive" or "presumptive positive"). A negative result at this stage means no further testing is required.
Confirmatory testing
If the screening result is non-negative, the sample is sent to a NATA-accredited laboratory for confirmatory testing. The laboratory uses gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS/MS) to confirm the presence and quantity of the specific substance. This is a more accurate and definitive test than the initial screen.
Result and action
Laboratory confirmation typically takes 2 to 5 business days. If confirmed positive, the employer follows the process set out in their drug and alcohol policy. If the laboratory result is negative (i.e., the initial screen was a false non-negative), the employee is cleared and no further action is taken. Employers should not take disciplinary action based on a screening result alone - confirmation is required for a fair process.
Important: Employers should not take disciplinary action or terminate employment based on a non-negative screening result alone. The confirmatory laboratory test is the definitive result. Taking action before confirmation exposes the employer to unfair dismissal risk if the screen was a false positive. The employee should be stood down from safety-critical duties pending confirmation, but final action should wait for the lab result.
What Employers Should Know
When setting up or reviewing your workplace drug testing program, the standard AS/NZS 4308 five-drug panel covers the substances most relevant to workplace safety risk. Extended panels are available for employers who need broader coverage based on their specific risk assessment.
Your testing provider should be able to advise on which panel is appropriate for your industry and roles. At Wellworx, we deliver on-site drug and alcohol testing across Sydney using AS/NZS 4308 compliant procedures with instant screening results. Contact us to discuss your testing requirements.
Frequently Asked Questions
Does a standard workplace drug test detect alcohol?
Alcohol is not part of the standard AS/NZS 4308 drug panel. It is tested separately using a breath test (breathalyser). Most workplace drug and alcohol testing programs include both a drug screen and a breath alcohol test as separate components of the same testing session.
Will my prescription medication show up on a workplace drug test?
Some prescription medications can produce a non-negative result on a screening test, including codeine-based pain medications, benzodiazepines for anxiety, and dexamphetamine for ADHD. Employees should declare prescribed medications before testing. A valid prescription typically means the result is not treated as a policy breach, though fitness for duty in safety-critical roles may still need to be assessed.
How long does cannabis stay in your system for a workplace drug test?
In urine, cannabis can be detected for 3 to 30 days depending on frequency of use. Occasional use may be detectable for 3 to 5 days, while regular heavy use can be detected for up to 30 days. In saliva, cannabis is typically detectable for up to 24 hours. These are approximate windows and vary between individuals.
Key Takeaways
- Standard panel tests 5 drug classes
- AS/NZS 4308 compliant testing
- Extended panels available
- Alcohol tested separately via breath test
- Prescription medications can be declared
- Confirmatory lab testing for non-negatives
- On-site testing across Sydney
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Content reviewed by Jovi Villanueva, AHPRA Registered Physiotherapist, SIRA Approved Provider, Principal Physiotherapist at Wellworx Workplace Solutions.
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