District of Columbia cannabis testing requirements

Required tests

• Potency
• Terpenes
• Pesticides
• Residual solvents
• Heavy metals
• Microbials
• Mycotoxins
• Water activity
• Moisture
• Foreign matter
• Homogeneity
• Other (see notes)

ISO/IEC 17025 accreditation

Required within a set period. 22-C DCMR 6404: a lab must be accredited to ISO/IEC 17025 by an ILAC-signatory body within 6 months of registration, or the Board may suspend or revoke it. Labs must also stay in good standing in a Board-approved proficiency testing program.

Notes

• Rules: 22-C DCMR chapters 64 (testing laboratories), 65 (cannabis testing) and 66 (adulterated cannabis). Chapter 65 was rewritten effective 25 February 2026 (73 DCR 2136).
• Each batch: moisture, water activity (below 0.65 aw), cannabinoids (THCA, THC, CBDA, CBD, CBN), foreign matter, microbials, mycotoxins, heavy metals, pesticides, fertilizer residue, residual solvents, and a cannabinoid and terpene profile.
• Edibles also need homogeneity testing and a product assessment (pH and water activity) to screen for potentially hazardous food.
• Microbials: E. coli under 100 CFU/g, Salmonella absent, total aerobic count and total yeast and mold 100,000 CFU/g or less.
• Heavy metals: arsenic, cadmium, lead and mercury at minimum; limits are also set for barium, chromium, selenium and silver.
• Mycotoxins: total aflatoxins B1, B2, G1, G2 and ochratoxin A, each 20 µg/kg or less. Pesticides: limits for 48 listed pesticides and plant growth regulators.
• Other: a fertilizer and nutrient panel (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Zn, Mo, Na, Cl) plus any fertilizer the grower discloses.
• Lab staff must collect samples on site at the cultivation center; results go into the District's tracking system before sale.
• Testing labs may not share ownership with any other licensed cannabis business.
• Adult use: Initiative 71 (in effect 26 February 2015) lets adults 21 and over possess up to 2 oz, gift up to 1 oz and grow up to six plants at home. Selling any amount remains an offense.
• The Alcoholic Beverage and Cannabis Board regulates the medical program under Mayor's Order 2020-099.