How to Read Pesticide Results on Your Cannabis COA

The pesticide page of a cannabis certificate of analysis can feel like a chemistry exam you did not agree to take. One column says ND. Another says LOQ. The result is in µg/g, the legal limit is hidden in a state table, and a large green PASS seems to settle the matter.

That pass is useful. It is not the same as “zero pesticides” or “tested for every chemical.” It means the sample met one program’s rules for the listed panel.

Professor High’s rule is simple: match the product, find the result, check the unit, compare the correct limit, then read the qualifier. Do those steps in that order and most pesticide panels become manageable.

For the rest of the report, start with our complete guide to reading cannabis lab results. This guide stays focused on pesticide rows.

First, know what the pesticide panel can prove

A licensed lab receives a sample from a production batch. It prepares a small portion, runs the state’s required pesticide panel, applies lab quality checks, and reports its findings on the COA. The batch passes or fails under the state’s rules.

Three boundaries matter:

• The result describes the tested sample, not every atom in every package.
• The panel covers the named analytes, not every pesticide or plant-growth chemical in existence.
• The action limit is a regulatory decision point, not a universal line between harmless and poisonous.

Those limits define the question being answered. Our guide to cannabis chain of custody follows the sample from collection to report. Our analysis of why cannabis lab standards vary covers the bigger system.

The six fields that matter most

COA layouts differ, but useful pesticide rows share these fields.

You may also see a column for the test method, uncertainty, dilution, or a footnote code. Never skip the legend. A lab’s “BQL,” “<LOQ,” or “trace” label only means what that report says it means.

Step 1: Match the COA to the product in your hand

Before reading one pesticide value, compare the producer, product type, batch or lot number, and package identifier. A real lab report for the wrong batch is still the wrong report.

Also check the sample, received, and report dates. A stale report raises different questions from a fresh one, as our guide to when a cannabis COA is too old explains. Scan the package QR code when possible. If it opens a brand homepage instead of the batch-specific report, ask for the original.

Step 2: Confirm the panel status—but keep reading

Look for pass, fail, or an equivalent overall pesticide status. Then inspect the individual rows.

A pass usually means no result crossed the decision point and required lab controls were acceptable. It may include residues below a numerical limit. Some rules instead require non-detection for certain chemicals.

A blank row, “NT,” or “not reported” is not ND. If a required panel is missing, do not fill the gap with optimism. This is one of the dispensary red flags worth checking before you buy.

Step 3: Decode ND, LOD, and LOQ

These terms sound alike but do different jobs.

LOD — limit of detection: the lowest level where the method can reliably notice a signal under its defined rules.

LOQ — limit of quantitation: the lowest level where the lab can report an amount with its required performance.

ND — not detected: the lab did not detect the analyte at or above the method’s stated detection threshold. ND does not establish absolute zero.

<LOQ or BQL — below quantitation limit: the amount is below the lab’s reliable measuring range. Depending on the lab’s legend, there may be a signal between the LOD and LOQ, or the lab may be grouping all low results under one code.

The method limits should be low enough to enforce the state limit. If an action limit is 0.20 µg/g but the lab’s LOQ is 0.50 µg/g, the method cannot reliably measure around the decision point. That deserves a question for the lab or regulator.

California’s final 2026 rule, for example, defines LOD using a signal-to-noise ratio of at least 3:1 for chromatographic work and LOQ at 10:1. Those are method-performance concepts, not consumer exposure limits.

Step 4: Put every number in the same unit

For pesticide results reported by mass, these conversions are especially useful:

• 1 µg/g = 1 mg/kg = 1 ppm
• 1 ng/g = 1 µg/kg = 1 ppb
• 1 ppm = 1,000 ppb

So a result of 0.07 µg/g is also 0.07 ppm or 70 ppb. An action limit of 0.20 µg/g is 200 ppb. Compare 70 with 200—not 70 with 0.20.

Step 5: Compare the result with the right action limit

Find the current regulator table for the state where the regulated product was tested and sold. Match all four details:

1. The pesticide name or CAS number
2. The product type or route, when the rule separates them
3. The unit
4. The rule and effective date that applied to the test

Do not borrow a California limit for a Washington product. Do not use a non-inhalable limit for flower. Do not assume a familiar agricultural food tolerance is the cannabis cutoff. The U.S. EPA explains that food tolerances are commodity-specific maximum residues. State cannabis action levels are a different regulatory tool.

Rules can change quickly. California approved a new pesticide rule on July 27, 2026, with an October 1, 2026 effective date. COAs on either side may face different requirements. Check the current DCC rule instead of copying numbers here.

Washington’s table sets myclobutanil at 0.20 µg/g and acephate at 0.40 µg/g. It sets 0.1 ppm as the default for an unlisted, disallowed pesticide. Yet a disallowed pesticide below that level may still bring an administrative violation. A compliance cutoff is not permission to apply it.

A worked pesticide-panel example

Here is a hypothetical Washington-style flower COA. Action limits come from the state table. Results and method limits are invented for teaching.

Here is the reading process:

1. The units match. Results and action limits are all µg/g.
2. The method can see below the cutoffs. Each LOQ is lower than its action limit.
3. ND is bounded. Acephate is below the 0.02 µg/g LOD, not known to be zero.
4. <LOQ needs the legend. Do not invent a value for bifenazate.
5. The numeric comparisons are direct. Myclobutanil is below its cutoff; carbofuran is above its cutoff.
6. One failed row fails the panel. The large overall badge should say fail.

If a value sits exactly on the line, do not outvote the certified report with hidden calculator digits. State rules control rounding, significant figures, measurement rules, and the final decision. Verify the original COA or ask the issuing lab.

Why the tested list matters as much as the result

Taylor and Birkett’s 2020 review, “Pesticides in cannabis: A review of analytical and toxicological considerations,” found a patchwork of analytical approaches and noted that low reported residue levels do not answer questions about chronic low-dose effects. The cannabis matrix is chemically complex, so labs may need both liquid- and gas-chromatography methods to cover compounds with different properties.

Maguire, Call, Cerbu, Jambor, and Benavides-Montes (2019) validated a method for 367 pesticides and tested 100 Oregon flower samples. Four held pesticides outside Oregon’s panel at the time. Three held regulated pesticides above state limits. This is not today’s failure rate. It shows why “required analytes passed” differs from “no other pesticide was present.”

Route matters too. Sullivan, Elzinga, and Raber (2013) tested flower spiked with three pesticides and one growth regulator. Residue recovery reached 69.5% in some device-and-compound pairings. This small, older lab study is not a real-world exposure estimate. It does challenge the idea that heat destroys every residue.

The final product matters as well. Extraction and processing can change how residues are distributed. Match a vape or concentrate to its own report rather than borrowing the source flower’s COA. Pair this guide with how to spot a counterfeit vape cart and how vape oil changes with age.

What a passing pesticide panel does not tell you

A pass does not confirm good storage, rule out mold, validate the potency number, or predict how the product will feel. Those are separate questions.

Check suspect flower with our mold-versus-trichomes guide. Read why some flower labels overstate certainty, and learn how dispensary labels can mislead. Even a clean COA cannot repair a broken retail seal or poor post-test storage; use our cannabis freshness and storage guide for that layer.

“Organic,” “living soil,” and “pesticide-free” marketing are not substitutes for a batch-specific compliance report. A careful grow method can be meaningful, but the pesticide table answers a narrower lab question.

Your 60-second pesticide checklist

Before buying, ask:

1. Does the COA match this exact product and batch?
2. Is the pesticide panel marked pass, and are the rows visible?
3. Are ND, LOD, LOQ, and other codes defined in the legend?
4. Do the result and action limit use the same unit?
5. Is the LOQ at or below the action limit?
6. Does the regulator’s current table match the state, product route, and test date?
7. Are any rows blank, not tested, amended, or subcontracted?
8. Can you verify the lab and report through an official source?

A good dispensary should help you find the original, not rush you past the question. See our dispensary buyer’s guide before your next visit.

Key takeaways

Read pesticide results as a chain of evidence, not a green sticker. First match the batch. Then identify the analyte, result, unit, method qualifier, and current state action limit. ND means below a stated detection threshold. It does not mean mathematical zero. A pass means the tested sample met the program’s decision rules for its panel.

Use TIWIH’s COA scanner to surface key fields, compare products side by side, and save the products you actually try. Once the safety panels and product identity make sense, explore High Families to compare broader chemistry instead of choosing by THC alone.

Frequently asked questions

Does ND mean pesticide-free?

No. ND means the lab did not detect that analyte at or above its stated detection threshold. It does not prove absolute zero, and it says nothing about compounds outside the panel.

Can a passing cannabis product contain a measurable pesticide residue?

Yes, when the governing rule uses a numerical action limit and the measured result is below it. Other analytes or programs may require non-detection. The current state rule and COA legend control the answer.

Is the action limit a guaranteed safe exposure level?

No universal guarantee fits every person, route, product, or exposure pattern. An action limit is the regulator’s compliance decision point. It should not be presented as a personal medical risk calculation.

Why do inhalable and non-inhalable limits differ?

Regulators may account for route, product amount, toxicology data, and other policy inputs differently. Use the column for the actual product. Do not apply an edible cutoff to flower or a vape.

What if the COA does not show an action limit?

Open the current official regulator table and match the analyte, CAS number, route, unit, and test date. If the result or qualifier still cannot be interpreted, ask the lab or regulator rather than guessing.

Does an organic label replace pesticide testing?

No. A cultivation claim and a lab result answer different questions. Look for the batch-specific compliance COA even when the product uses organic or regenerative language.

Sources

• Washington State Legislature — WAC 314-55-108: Pesticide Action Levels.
• Washington State Legislature — WAC 16-309-210: Pesticide Testing.
• California Department of Cannabis Control — Testing Laboratories.
• California Department of Cannabis Control — DCC-2025-03-R Pesticide Testing Rulemaking.
• U.S. Environmental Protection Agency — Regulation of Pesticide Residues on Food.
• Taylor and Birkett (2020), “Pesticides in cannabis: A review of analytical and toxicological considerations,” Drug Testing and Analysis.
• Maguire, Call, Cerbu, Jambor, and Benavides-Montes (2019), “Comprehensive Determination of Unregulated Pesticide Residues in Oregon Cannabis Flower by Liquid Chromatography Paired with Triple Quadrupole Mass Spectrometry and Gas Chromatography Paired with Triple Quadrupole Mass Spectrometry,” Journal of Agricultural and Food Chemistry.
• Sullivan, Elzinga, and Raber (2013), “Determination of Pesticide Residues in Cannabis Smoke,” Journal of Toxicology.

Regulatory sources and effective dates were checked August 22, 2026. Cannabis testing rules change. This guide is educational and is not medical, legal, or toxicology advice.