Michigan cannabis testing requirements

Required tests

• Potency
• Pesticides
• Residual solvents
• Heavy metals
• Microbials
• Water activity
• Foreign matter
• Homogeneity
• Vitamin E acetate
• Other (see notes)

ISO/IEC 17025 accreditation

Required within a set period. 12 months. R 420.305(1): a lab must be accredited to ISO/IEC 17025:2017 for all required safety tests in at least one matrix, by an ILAC-recognized body or an agency-approved entity, within 1 year after its license is issued.

Notes

• Rules: Mich. Admin. Code R 420.301-420.308 (Marihuana Sampling and Testing, last amended March 7, 2022) plus the CRA Sampling and Testing Technical Guidance, v5.2 (revised Sept 23, 2024).
• Microbials: total yeast and mold, total coliforms, STEC, Salmonella, Aspergillus (flavus, fumigatus, niger, terreus). Flower yeast/mold limit: 10,000 CFU/g medical, 100,000 adult-use.
• Metals: Pb, inorganic As, Hg, Cd, total Cr, plus Ni for inhaled products and Cu for vapes.
• Water activity: ≤0.65 for flower, ≤0.85 for edibles. Homogeneity for infused products: 10 servings, variation within ±15%.
• Mycotoxins (aflatoxins B1, B2, G1, G2, ochratoxin A): only on agency request, and required after any Aspergillus failure before remediation (since Dec 1, 2022). Terpene testing is optional.
• Other: medium-chain triglycerides (MCT) in vape cartridges (mandatory since Oct 1, 2024); pH for infused beverages.
• Pending: rule set 2023-25 LR rewrites the marihuana rules (second public hearing July 23, 2026; not yet final). The 2024 draft would codify the guidance and add homogeneity testing for every batch and terpene testing of flower.