Overview. Mycotoxins are toxic fungal metabolites that may remain even when viable mould is no longer detectable. Cannabis can become vulnerable during cultivation, drying and storage, making preventive moisture control and representative sampling essential.
Why mycotoxins matter
Aflatoxins and ochratoxin A are of particular concern because of their toxicity and persistence. Visual inspection or microbial enumeration cannot reliably exclude them.
Sources and process conditions
Plant stress, delayed drying, high humidity, poor airflow and unsuitable storage can support toxin-producing fungi. Contamination may be highly localised.
Sampling challenge
A small contaminated pocket can be missed by a limited sample. Sampling plans should consider batch size, container distribution and the possibility of clustering.
Analytical methods
LC-MS/MS is widely used because it can provide sensitive, selective multi-analyte detection. HPLC with fluorescence or other validated approaches may also be suitable.
Cleanup and recovery
Immunoaffinity or other cleanup can reduce matrix interference. Recovery should be demonstrated in the specific cannabis matrix and concentration range.
Specifications and reporting
Limits should reflect applicable law and product use. The method reporting limit should sit comfortably below the action limit.
Investigation and prevention
Positive findings should trigger review of cultivation, drying, water activity, storage, supplier and sampling controls. Destruction or rejection may be required depending on the result and legal framework.
Practical reference table
| Analyte | Typical concern | Control focus |
|---|---|---|
| Aflatoxin B1 | High toxicity | Low reporting limit and representative sampling |
| Total aflatoxins | Combined exposure | Accurate individual quantification |
| Ochratoxin A | Storage-related fungal toxin | Drying and storage control |
| Fungal count | Indirect indicator only | Microbiology plus toxin testing |
| Water activity | Growth-potential indicator | Drying and packaging trend |
Control and decision path
Frequently asked questions
Can a low mould count prove absence of mycotoxins?
No. Toxins may remain after fungal viability decreases.
Why is sampling especially important?
Mycotoxin contamination can be highly localised.
Is LC-MS/MS always required?
No, but the chosen method must meet the necessary selectivity and sensitivity.
Can contaminated material be remediated?
Any remediation would require legal acceptability and strong validation; rejection is often the safer outcome.
What process controls reduce risk?
Rapid controlled drying, humidity management, clean storage and supplier oversight.
Primary references and guidance
- European Pharmacopoeia mycotoxin chapters
- ICH Q2(R2)
- EU GMP Part I, Chapter 6
- WHO GACP
- ISO 17025
- Applicable national cannabis limits
- Relevant European food-contaminant principles where scientifically applicable
Confirm the current effective revision and national applicability before operational or regulatory use.