Massachusetts cannabis testing requirements

Required tests

• Potency
• Pesticides
• Residual solvents
• Heavy metals
• Microbials
• Mycotoxins
• Vitamin E acetate

ISO/IEC 17025 accreditation

Required. 935 CMR 500.050(7)(a): before final licensure a lab must be accredited to the current ISO 17025 by an ILAC-signatory body, or certified, registered or accredited by an organization the Commission approves.

Notes

• Rules: 935 CMR 500.160 (adult use) and 501.160 (medical), plus the CCC Protocol for Sampling and Analysis of Finished Marijuana Products (revised Dec 30, 2021) and its exhibits.
• Metals: arsenic, cadmium, lead, mercury. Pesticides: any residue above 10 ppb fails; the protocol names 9 target pesticides.
• Microbials: total aerobic count, yeast and mold, total coliforms, bile-tolerant gram-negative bacteria, pathogenic E. coli, Salmonella. Mycotoxins: aflatoxins B1, B2, G1, G2, ochratoxin A.
• No moisture, water activity, foreign matter or terpene test is mandated. Edibles must be homogeneous (10% of the infused portion may not hold over 20% of total THC); single servings may vary ±10%.
• Administrative orders: since April 1, 2025 one full-panel sample goes to a single lab for all compliance tests; since mid-2025 labs upload every COA to Metrc.
• In flux: the CCC is drafting a standalone testing section of 935 CMR and revising the testing protocol (meeting early Oct 2026, draft vote Dec 2026, final vote planned March 2027).
• Chapter 65 of the Acts of 2026 ended vertical integration for medical marijuana establishments; emergency regulations took effect June 18, 2026.