Understanding Cut-off Levels
Drug testing is more than a workplace policy – it’s a critical component of risk management, compliance, and employee safety.
What determines whether a drug test result is not-negative/unconfirmed or negative? Drug screening cut-off levels, as defined by the Australian and New Zealand Standards.
Cut-off levels are the minimum concentrations of a drug and/or its metabolites that must be present in a biological sample for a drug test to be reported as confirmed positive. These cut-off levels are designed to ensure accuracy and consistency, reduce false positives, and align with legal and safety requirements.
Australian and New Zealand Standards for Workplace Drug Testing
To maintain compliance and fairness, workplace drug testing in Australia and New Zealand follows two key standards:
AS/NZS 4308:2023 Procedures for specimen collection and the detection and quantification of drugs in urine.
AS/NZS 4760:2019 – Procedures for specimen collection and the detection and quantification of drugs in oral fluid.
These standards define specific cut-off levels for different drug classes. They are based on concentrations that can be reliably detected under both workplace and laboratory testing and consider real-world factors – such as passive cannabis exposure – to ensure fair and accurate results.
AS/NZS 4760:2019 Oral Fluid Screening Cut-off Level
Screening Cut-off | |
Opiates | 50 ng/mL |
Amphetamine Type Substances | 50 ng/mL |
Benzodiazepines | 10 ng/mL (optional) |
Cannabinoids (THC) | 15 ng/mL |
Cocaine & Metabolites | 50 ng/mL |
Oxycodone | 40 ng/mL |
Note: Benzodiazepine testing in oral fluid is optional and may be included based on workplace policy.
AS/NZS 4308:2023 Urine Screening Cut-off Level
Drug Class | Screening Cut-off |
Amphetamine Type Substance | 300 µg/L |
Benzodiazepines | 200 µg/L |
THC Metabolites | 50 µg/L |
Cocaine & Metabolites | 150 µg/L |
Opiates | 300 µg/L |
Cut-off Levels are Based on Scientific Research and Real-world Testing Conditions
- This ensures workplace drug testing is fair and legally defensible
- Ensures passive exposure (e.g., second-hand cannabis smoke) is unlikely to trigger false positives
- Protects employers and employees under a consistent compliance framework
Stay Compliant and Protect Your Workforce
Understanding cut-off levels is essential for organisations to apply policies and procedures correctly, maintain fairness in interpreting results, and provide the right support and education for your workplace.
For employees, education and awareness builds transparency and trust, helping make informed choices about medications and/or lifestyle factors, and reinforcing that drug testing is about preventing and safety – not punishing.
Explore Alcolizer Technology’s Workplace Drug & Alcohol Testing Solutions
Your one provider for workplace drug and alcohol safety – continue reading about our workplace testing solutions.
