What are the Australian Standard Drug Class Screening Cut-off Levels

The Australian Standard Drug Class Screening Cut-off Levels are essential benchmarks for ensuring accurate and reliable drug testing in various settings, including workplaces. These standards are defined under AS/NZS 4308:2023 for urine testing and AS/NZS 4760:2019 for oral fluid testing.

AS/NZS 4760:2019 (Oral Fluid Testing) – outlines the cut-off levels for oral fluid testing, which is increasingly used due to its non-invasive nature and ability to detect recent drug use. The cut-off levels for oral fluid testing are as follows:

• Opiates (50 ng/mL)
• Amphetamine Type Stimulants (50 ng/mL)
• Benzodiazepines (10 ng/mL) – optional based on workplace & policy
• Cannabis (THC) (15 ng/mL)
• Cocaine (50 ng/mL)
• Methamphetamine (50 ng/mL)
• Oxycodone (40 ng/mL)

AS/NZS 4308:2023 (Urine Testing) – replaces the previous AS/NZS 4308:2008 standard. The cut-off levels for different drug classes in urine testing are designed to detect substances reliably in a laboratory setting. Here are the cut-off levels for various drug classes:

• Amphetamine Type Stimulants (300 ug/L)
• Benzodiazepines (200 ug/L)
• Cannabis Metabolites (50 ug/L)
• Cocaine Metabolites (150 ug/L)
• Opiates (300 ug/L

Importance of Cut-off Levels

The cut-off levels are based on extensive research and are designed to balance sensitivity and specificity. For instance, the cut-off level for cannabis metabolites takes into account passive smoking, ensuring that a positive result cannot be obtained from passive exposure. 

Understanding the Australian Standard Drug Class Screening Cut-off Levels is crucial for anyone involved in drug testing, whether in a workplace or other settings. These standards ensure that drug tests are reliable, accurate, and fair, providing a robust framework for detecting substance use.

For more detailed information on these standards, click here.