Testing cannabis for contaminants: panels, laboratory selection and accreditation
Why a cannabinoid profile is not a contaminant test, and how to assess a laboratory’s scope, matrix coverage and accreditation.
Composition testing is not contaminant screening
THC and CBD values describe selected constituents. They do not rule out pesticides, metals, microorganisms, mycotoxins or residual solvents. These categories need separate examinations and a specific analyte list. Even within a category, coverage is limited: a pesticide panel does not automatically include every possible compound. Health Canada describes distinct analytical tasks for cannabinoids and other contamination questions. That foreign technical context is used here to explain the distinction, not as a statement of Swiss testing obligations.
Match the panel to the product
Begin with product form and intended use. Flower, an extract and a food are not interchangeable. Record the actual target substances, relevant limits and whether the procedure suits the matrix. The choice can be informed by questions about raw material, production and processing. This is a practical decision structure, not a remote diagnosis of contamination. Choosing a broad voluntary panel also does not replace a product-specific legal assessment. The report’s scope should be clear enough to explain what remains untested.
Check accreditation precisely
ISO/IEC 17025 concerns competence, impartiality and consistent operation of testing and calibration laboratories. SAS is Switzerland’s national accreditation body. Recognition relates to a particular scope. Check the identified testing body, current scope and relevant method or matrix rather than looking only for a logo. A management-system certificate is not the same as demonstrated analytical competence for a specific test. CannabisLabor.ch claims no accreditation of its own. Ask the laboratory to identify which parts of an offered panel are within its accredited scope.
Keep Swiss product categories separate
FSVO describes distinct classification requirements for foods made with hemp or cannabinoids. An analytical number alone does not resolve a product classification question. Equally, the pilot trials described by FOPH are geographically and temporally limited research under specific conditions. Testing in a research project is not a generally available analytical service. Listing a cantonal authority or research project on a regional guide establishes neither a partnership with this platform nor private sample acceptance. Consult the responsible body for its actual remit.
Prepare a defensible laboratory selection
Request an example report structure, precise service description and available evidence of competence. Clarify sampling, acceptance conditions, subcontracting and the meaning of results below quantification limits. If a finding will trigger a decision, establish who will interpret it professionally. Low values should not be presented as an unlimited safety guarantee. CannabisLabor.ch currently accepts neither enquiries nor submissions; its preparation dialog states that without promising a service. These questions are useful before any future agreement with a named qualified laboratory.
| Question | Scope to clarify | Not automatically established |
|---|---|---|
| Which cannabinoids? | Named compounds and method | Absence of contaminants |
| Which residues? | Specific pesticide or metal list | Every possible contaminant |
| Which microorganisms? | Agreed microbiological parameters | Unlimited safety |
Questions to clarify locally
- Ask for named tested parameters rather than ‘contaminant-free’ claims.
- Check matrix coverage and the specific method’s suitability.
- Verify the accreditation body and current scope.
- Clarify sampling, subcontracting and interpretation.
- Distinguish research, official control and private analysis.