Two jars with the same strain name can come from different batches. Massachusetts sets testing rules for medical marijuana and requires the label to carry a batch number, and this page walks through both.
What gets tested
Testing of marijuana products shall be performed by an Independent Testing Laboratory in compliance with a protocol in a form and manner determined by the Commission(state regulation).
Marijuana and Marijuana Products shall be tested for the Cannabinoid profile and for contaminants, including mold, mildew, heavy metals, plant growth regulators, and the presence of Pesticides(state regulation).
Final ready-to-sell Marijuana Vaporizer Products shall be screened for heavy metals and Vitamin E Acetate(state regulation).
The Commission may require additional testing(state regulation).
What the label says about the batch
The label on marijuana must carry a batch number, sequential serial number, and bar code when used, to identify the batch associated with manufacturing and Processing(state regulation).
The label must also carry a statement and a seal certifying that the product has been tested for contaminants, that there were no adverse findings, and the date of testing(state regulation).
How long a result counts
A testing result is valid for a period of one year, and Marijuana and Marijuana Products with testing dates in excess of one year shall be deemed expired and may not be dispensed, sold, transferred or otherwise conveyed until retested(state regulation)(state regulation).
A treatment center must maintain the results of all testing for no less than one year(state regulation).
Marijuana with testing dates in excess of one year shall be deemed expired and may not be dispensed or sold until retested(state regulation).
When a batch fails
A licensee that receives notice of a failed contaminant test must either reanalyze the product without remediation, remediate the identified contaminants, or dispose of the product(state regulation).
Summary of the regulation on testing (935 CMR 501.160), as cited in the sentences around it.| Choice | What the regulation requires |
|---|
| Reanalyze without changing the product | A sample from the same batch goes back to the lab that failed it, then a second lab must confirm it passed |
| Remediate | A new sample goes to a licensed lab for a full panel test, and a failing product may be remediated at most twice |
| Dispose | The product is destroyed under the disposal rules |
For reanalysis, a sample from the same batch must be submitted at the laboratory that provided the initial failed result(state regulation).
To be considered passing and therefore safe for sale, the sample shall have passed the Second Confirmatory Test at a second ITL(state regulation).
Any failing marijuana may be remediated a maximum of two times(state regulation).
Marijuana that fails any test after the second remediation attempt may not be sold, transferred or otherwise dispensed to Consumers, Patients or Licensees(state regulation).
A treatment center's policy must include notifying the Commission within 72 hours of testing results indicating that the contamination cannot be remediated(state regulation).
A treatment center shall have a written policy for responding to laboratory results above acceptable limits, and the policy shall be available to Registered Qualifying Patients and Personal Caregivers(state regulation).
Short answers
How long does a lab result count?
Testing results are valid for a period of one year, and the regulation requires older product to be retested(state regulation)(state regulation).
Can product past its test date be sold?
Marijuana with testing dates in excess of one year may not be dispensed or sold until retested(state regulation).
How many times can a failed batch be remediated?
Any failing marijuana may be remediated a maximum of two times(state regulation).
Can a patient see the center's policy on failed results?
The policy shall be available to Registered Qualifying Patients and Personal Caregivers(state regulation).
Advanced Dispensary in Peabody
Advanced Dispensary in Peabody is being built and has no opening date.
Sources
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Testing of Marijuana Products shall be performed by an Independent Testing Laboratory in compliance with a protocol(s) established in accordance with M.G.L. c. 94G, § 15 and in a form and manner determined by the Commission"
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Marijuana and Marijuana Products shall be tested for the Cannabinoid profile and for contaminants as specified by the Commission including, but not limited to, mold, mildew, heavy metals, plant growth regulators, and the presence of Pesticides."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "final ready-to-sell Marijuana Vaporizer Products shall be screened for heavy metals and Vitamin E Acetate (VEA)"
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "The Commission may require additional testing."
- "935 CMR 501.105, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "A batch number, sequential serial number, and bar code when used, to identify the batch associated with manufacturing and Processing"
- "935 CMR 501.105, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "A statement and a seal certifying that the product has been tested for contaminants, that there were no adverse findings, and the date of testing"
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Testing results shall be valid for a period of one year."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Marijuana and Marijuana Products with testing dates in excess of one year shall be deemed expired and may not be dispensed, sold, Transferred or otherwise conveyed until retested."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "An MTC shall maintain the results of all testing for no less than one year."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "A Licensee that receives notice that Marijuana or a Marijuana Product it has submitted for testing has failed any test for contaminants shall either reanalyze the Marijuana or Marijuana Product without remediation, take steps to remediate the identified contaminants or dispose of the Marijuana or Marijuana Product."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "a sample from the same batch shall be submitted for reanalysis at the ITL that provided the initial failed result"
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "To be considered passing and therefore safe for sale, the sample shall have passed the Second Confirmatory Test at a second ITL."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Any failing Marijuana or Marijuana product may be remediated a maximum of two times."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Any Marijuana or Marijuana product that fails any test after the second remediation attempt may not be sold, transferred or otherwise dispensed to Consumers, Patients or Licensees."
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "Notifying the Commission within 72 hours of any laboratory testing results indicating that the contamination cannot be remediated"
- "935 CMR 501.160, Cornell Legal Information Institute" (law.cornell.edu, read November 5, 2026): "An MTC shall have a written policy for responding to laboratory results that indicate contaminant levels are above acceptable limits ... Such policy shall be available to Registered Qualifying Patients and Personal Caregivers."
