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Right alongside Oregon’s newly established microbiological testing requirements, we’ve fielded a flood of associated questions. The new microbial and heavy metals testing rules announced in 2022 and launched a year later may have helped align the state with other markets across the country. But for a cannabis cultivator or manufacturer, navigating the complexities of jargon-laden legislation is not straightforward.

Particularly for operators facing test failures, there is a need to clarify the options for retesting, reanalysis, and remediation. If you have a failed microbiological compliance test results on your hands, a simplified summary of the available options under OAR 333-007-0450 are outlined below.

Oregon’s Microbial Testing: New Rules

According to the Permanent Administrative Order issued last year by Oregon’s Health Authority:

Marijuana and usable marijuana harvested on and after March 1, 2023 will be required to be tested for heavy metals and microbiological contaminants if the marijuana or usable marijuana is intended for use by a consumer or will be transferred to a processor or processing site to make a cannabinoid product, except for an inhalable cannabinoid product.

Now, microbial testing requires panels for four dangerous pathogens: Aspergillus flavus (A. fumigatus, A. niger, and A. terreus), Shiga toxin-producing E. coli, Salmonella spp. and Aspergillus speciation.

Following the new rules, microbiological contaminant in cannabis and hemp is one gram per submitted sample.

Any cannabis harvested on or after March 1, 2023 has to undergo expanded microbiological testing whether it is destined for sale as is or heading to post-processing. If it is destined for further processing into a concentrate, extract, or finished inhalable cannabinoid product, testing happens later on the final product.

For all inhalable cannabinoid products, finished concentrates, and extracts, microbiological testing happens on the finished item — technically, after the product is complete but before packaging. Even if this test was done before (for example, before extraction), the results do not transfer to the finished product, and a new test will need to be completed.

What Happens if Your Sample Fails for Microbiological Contamination?

If a sample fails microbiological testing, under most circumstances, it doesn’t get assigned an immediate destruction order.

The good news is that there are several possible options, including retesting, reanalysis, and remediation, all designed to prevent total product loss for the producers while keeping consumers safe.

Retesting and Reanalysis

Following a failed test result, you can request a reanalysis of the same sample within seven days. Reanalysis must be completed by the same laboratory that performed the first test within 30 days.

If the sample fails again, then “all associated batches must be held for destruction.”

But if the sample passes its second run-through, the laboratory is required to take a new sample for retesting. A third analysis must be done by a different lab, rather than the original lab.

A failed result from the new sample will result in the batch getting assigned a destruction order. But if the new sample passes, then the product can be transferred.

Options for Failed Marijuana and Usable Marijuana

If your batch has failed microbiological testing, there are two ways to potentially use the biomass without resorting to total destruction.


A failed batch may be remediated through a proven sterilization process like X-ray or ozone. Both technologies are used widely for remediation and decontamination in other industries, including medical devices, agriculture, and pharmaceuticals.

Oregon allows for a single round of remediation. Once remediated, the batch is subject to another round of compliance testing to ensure the microbiological contaminants have been destroyed. If the sample fails again, then the batch is held for destruction.


A second option for failed batches is to run through a solvent-based extraction process so long as the process “effectively sterilizes the batch,” as per the OHA.

In 2022, authors M.R June-Wells, F.W Fochtman, et al. published “From Contaminated Cannabis Material to Microbe-Free Extracts: A Real-World Test.” According to their investigation, hydrocarbon and supercritical carbon dioxide extraction “resulted in manufactured raw materials that were free of viable microbial contaminants that were evaluated during this study.” The authors concluded, “all tested microbial contaminants were not detected after the parent plant material was processed via solvent extraction.”

Solventless extraction is not an effective means of cleaning up a failed product. Although the heat of the rosin press may kill some microbiological life, solventless simply extracts compounds into a more concentrated form, including both the desirable and undesirable components.

Keep in mind that the final consumer product, which contains the concentrate or extract, must still go through additional microbiological, solvent, heavy metals, and mycotoxin testing as per the new testing guidelines for finished products. Failure on these tests means the product will be held for destruction.

Further Processing

Should more processed SKUs (including concentrates, extracts, finished inhalable cannabinoid products, and industrial hemp vapor products) fail testing, the only option available is further processing.

Once again, the new final product will need to undergo another round of compliance testing per the new regulations. If it fails at this stage, it has to be destroyed.

Facing a Failed Microbiological Test? You Have Options

Speak with an SC Labs Oregon Account Team today or call (503) 272-8830.