Kratom Extract Residual-Solvent Testing: How to Read a COA

Residual-solvent testing answers a narrow but important product-quality question: did volatile organic chemicals used or introduced during manufacturing remain in the finished material, and if so, at what measured level?

That question matters most for extracts. It cannot be answered from a package photo, an extraction-ratio claim, a total-alkaloid number, or a generic “lab tested” badge. It also cannot be answered by applying one universal panel to every product called kratom. A pure botanical leaf powder, a water extract, an ethanol extract, a concentrated 7-hydroxymitragynine product, and a synthesized derivative have different manufacturing histories. The evidence should match the actual material and process.

This guide is educational, not medical or legal advice. Kiody serves adults 21 and older and does not sell concentrated 7-OH products. A residual-solvent result does not prove that a product is safe, effective, approved by the U.S. Food and Drug Administration, or lawful in a particular jurisdiction.

The short version

A useful residual-solvent certificate of analysis, or COA, should let a careful reader answer at least six questions:

1. Is the tested sample the same finished lot as the product being evaluated?
2. Which solvents were actually included in the laboratory panel?
3. Does the panel reflect the solvents, reagents, processing aids, and cleaning agents that could reasonably be present from that product’s manufacturing history?
4. Is the analytical method suitable for the product matrix and the concentrations that matter?
5. Are the reporting limit and units sensitive enough to support the stated specification?
6. Who established the specification, and is the result being compared with the correct product-specific and exposure-based benchmark?

“Pass” is a conclusion. A strong COA also shows the observations behind it: analytes, results, units, method, reporting limits, lot identity, dates, and authorization.

What is a residual solvent?

The International Council for Harmonisation’s Q3C guideline defines residual solvents as volatile organic chemicals used or produced in manufacturing. Manufacturers generally cannot remove them completely through ordinary practical techniques. The quality task is therefore to avoid higher-concern solvents when possible, control any solvent that is justified, and show that finished-material exposure remains within an appropriate specification.

Three boundaries are easy to miss.

First, “residual solvent” is not a synonym for every contaminant. Pesticide residues, heavy metals, microbes, mycotoxins, and undeclared active ingredients require different analytical approaches. A residual-solvent panel does not substitute for those tests.

Second, water is not ordinarily treated as an organic residual solvent under Q3C. Calling a product “water extracted” may describe the main extraction medium, but it does not by itself establish that no volatile chemical could have entered through another step, processing aid, equipment-cleaning practice, or upstream ingredient.

Third, the fact that a solvent is familiar does not make its residual level irrelevant. Ethanol, acetone, ethyl acetate, and isopropanol are placed in Q3C’s lower-toxic-potential Class 3, but their identity, amount, maximum daily exposure, process consistency, and product-specific effects still matter.

Product form comes before panel selection

The words “kratom COA” hide several very different products. Before reading the result, identify what was made.

Product form	Typical residual-solvent question	Evidence that should not be substituted
Whole, crushed, or powdered botanical leaf	Were any fumigants, cleaning solvents, processing chemicals, or upstream solvents reasonably introduced?	An extract solvent panel from a different product or supplier
Pure-leaf capsules	Was the encapsulated leaf lot evaluated, and did capsule processing introduce another relevant source?	A COA for loose powder when the capsule lot identity cannot be linked
Water extract	Was water truly the only extraction medium, and were any later carriers, cleaners, or processing aids volatile organic chemicals?	The phrase “water extracted” without a process record
Ethanol extract	How much ethanol remains after concentration and drying, and are impurities or other solvents reasonably possible?	A single ethanol result if the process used additional solvents
Multi-solvent botanical extract	Does the panel cover every solvent reasonably likely to remain from extraction, fractionation, purification, and drying?	A standard five-solvent screen unrelated to the actual process
Enhanced or concentrated 7-OH product	What solvents and reagents were used during concentration, conversion, purification, formulation, and cleaning?	A botanical-leaf COA or a generic “full panel passed” statement
Synthesized or semi-synthesized derivative	What starting materials, reaction solvents, reagents, catalysts, intermediates, and by-products require control?	Botanical identity or ordinary leaf testing

This distinction is not merely technical. A process that concentrates or transforms an alkaloid can create a different risk and legal profile from ordinary botanical leaf. Residual-solvent testing can help evaluate one part of manufacturing quality, but it cannot determine whether the product is botanical, enhanced, synthesized, semi-synthesized, federally scheduled, or permissible under state law.

Why pure leaf and extracts should not share one generic claim

Pure leaf is milled plant material. An extract is made by transferring selected constituents into a medium and then, in many cases, concentrating or drying that material. Even if both products begin with Mitragyna speciosa, their manufacturing histories are not interchangeable.

For pure leaf, a supplier should document whether volatile solvents were used at all. If none were used or reasonably introduced, a risk assessment may support a targeted approach rather than an expansive extract panel. That decision still needs records. “We do not extract it” is useful process information, but it does not automatically address sanitation chemicals, supplier changes, cross-contact, or undocumented upstream treatment.

For an extract, the solvent inventory is foundational. The manufacturer should know which solvent grades were used, where they were introduced, how they were removed, whether they were recovered and reused, which drying parameters were controlled, and which chemicals contacted shared equipment. The finished-product COA should be traceable to that process.

A quality claim should therefore be specific. “Finished lot tested for the extraction solvents identified in its manufacturing process” conveys much more than “all-natural” or “solvent free.”

Start with a manufacturing-process map

The most defensible laboratory panel begins outside the laboratory. Map the manufacturing process from raw material through finished package.

A practical map records:

• the identity and grade of every extraction solvent;
• the identity of solvents used for washing, fractionation, recrystallization, conversion, chromatography, or formulation;
• solvent specifications and supplier certificates;
• whether recovered solvent is reused and how its quality is controlled;
• extraction temperature, time, ratio, and sequence;
• evaporation, vacuum, purge, and drying conditions;
• carriers, excipients, flavors, and coatings added later;
• equipment-cleaning agents and the controls preventing carryover;
• shared equipment and the preceding product or process;
• in-process checks and finished-product release tests;
• rework, blending, and lot genealogy; and
• changes that trigger reassessment.

FDA’s Botanical Drug Development guidance asks drug developers to describe processing steps, solvent quantities, temperatures, times, yields, and controls. That guidance is written for botanical drugs, not retail kratom, but its documentation logic is useful: a laboratory cannot design a meaningful process-specific panel when the manufacturer cannot describe the process.

Q3C is a benchmark, not a universal kratom law

ICH Q3C(R9) is a pharmaceutical residual-solvent guideline. It groups solvents by toxicological concern and supplies permitted daily exposures, or PDEs, and concentration limits for many solvents. It is valuable quality literacy, but it should not be misrepresented as an automatic legal pass/fail standard for every kratom product.

The distinction matters because:

• Q3C’s scope is pharmaceutical manufacturing;
• its Option 1 concentration limits assume a product mass of no more than 10 grams per day;
• a manufacturer’s serving directions and maximum daily amount affect exposure calculations;
• state or product-specific rules may impose different requirements;
• a company’s internal specification can be stricter;
• an unlisted solvent still requires a scientifically justified evaluation; and
• meeting a residual-solvent benchmark does not resolve FDA’s separate position on kratom products.

Use Q3C to understand risk classes, exposure calculations, and documentation—not to attach an unsupported “FDA compliant” claim to a finished kratom product.

The three Q3C solvent classes

Class 1: solvents to avoid

Class 1 solvents are known human carcinogens, strongly suspected human carcinogens, or environmental hazards. Q3C says they should not be used in the manufacture of drug substances, excipients, and drug products unless their use is strongly justified in a risk-benefit assessment.

Selected Q3C Option 1 limits are:

Class 1 solvent	Concentration limit
Benzene	2 ppm
Carbon tetrachloride	4 ppm
1,2-Dichloroethane	5 ppm
1,1-Dichloroethene	8 ppm
1,1,1-Trichloroethane	1,500 ppm

These numbers should not become a default marketing panel without process context. For example, benzene may be relevant as an impurity in another solvent even when it was not intentionally used. The manufacturer may need to control the incoming solvent’s purity, the finished material, or both.

Class 2: solvents to limit

Class 2 solvents are associated with inherent toxicity. Their permitted daily exposures and concentration limits vary substantially.

Selected Q3C Option 1 examples are:

Class 2 solvent	PDE	Option 1 concentration limit
Acetonitrile	4.1 mg/day	410 ppm
Dichloromethane	6.0 mg/day	600 ppm
Hexane	2.9 mg/day	290 ppm
Methanol	30.0 mg/day	3,000 ppm
N-Methylpyrrolidone	5.3 mg/day	530 ppm
Tetrahydrofuran	7.2 mg/day	720 ppm
Toluene	8.9 mg/day	890 ppm

The full Q3C table and its footnotes—not a shortened web summary—should govern any formal calculation. Chemical identity matters. “Hexane” on a process record should not be silently treated as every possible hydrocarbon mixture, and similar names do not establish analytical equivalence.

Class 3: solvents with lower toxic potential

Class 3 includes commonly used solvents such as acetone, ethanol, ethyl acetate, heptane, and 2-propanol. Q3C states that amounts of 50 milligrams per day or less, corresponding to 5,000 ppm or 0.5% under Option 1, would generally be acceptable without justification in its pharmaceutical framework.

“Class 3” does not mean “no limit” or “no need to measure.” A product may have a lower internal specification because of process capability, sensory characteristics, stability, packaging, intended daily mass, or another applicable requirement. A large maximum daily amount may also require an exposure calculation rather than casual comparison with 5,000 ppm.

Option 1 and Option 2: concentration is not the whole story

Q3C provides two ways to evaluate Class 2 solvents.

Option 1 uses the guideline’s concentration limit and assumes that no more than 10 grams of all product components are taken per day. It is a simple screen when that assumption is satisfied.

Option 2 evaluates the actual maximum daily exposure from all relevant components against the solvent’s PDE. It is necessary when the daily product mass exceeds 10 grams and can also provide a more product-specific assessment.

The basic conversion is:

daily solvent exposure in mg/day = result in ppm × maximum product mass in g/day ÷ 1,000

This works because ppm for a solid is commonly expressed as mg/kg.

Worked example 1: methanol below its PDE

Suppose a finished extract reports 1,200 ppm methanol and its documented maximum daily product mass is 1.5 grams.

1,200 × 1.5 ÷ 1,000 = 1.8 mg methanol per day

The Q3C PDE for methanol is 30 mg/day. The calculated exposure is below that pharmaceutical benchmark. This does not, by itself, establish that the product is lawful, suitable, correctly labeled, or released under a scientifically justified specification. It only completes the stated comparison.

Worked example 2: why the 10-gram assumption matters

Suppose a powdered product reports 250 ppm hexane and its maximum daily amount is 12 grams.

250 × 12 ÷ 1,000 = 3.0 mg hexane per day

The Q3C PDE for hexane is 2.9 mg/day. Although 250 ppm is numerically below the Option 1 table value of 290 ppm, the actual daily exposure is slightly above the PDE. A simple “250 is below 290” comparison would miss the daily-mass issue.

Worked example 3: converting ethanol percent to ppm

Suppose a dry extract reports 0.22% ethanol by mass.

1% = 10,000 ppm, so:

0.22% × 10,000 = 2,200 ppm

That result is below Q3C’s general 5,000 ppm Option 1 level for Class 3 solvents. The laboratory report should still make the basis clear, and the manufacturer should compare the result with its approved finished-product specification.

Unit literacy: ppm, mg/kg, µg/g, and percent

For a solid material measured on a mass basis:

• 1 ppm = 1 mg/kg;
• 1 ppm = 1 microgram per gram;
• 1% = 10,000 ppm;
• 0.5% = 5,000 ppm; and
• 0.1% = 1,000 ppm.

These equivalences do not permit careless comparisons across every matrix. A liquid result may be reported by mass, by volume, or after a density conversion. A COA should identify the basis. “500 ppm” without a matrix, unit basis, and method is incomplete.

Dry-basis and as-is results also differ. If moisture correction is applied, the report or underlying method should say so. A specification written on one basis should not be compared with a result reported on another.

How laboratories test volatile solvents

Many residual-solvent methods use headspace gas chromatography. A sealed vial containing the prepared sample is heated under controlled conditions. Volatile compounds partition into the gas above the sample. An aliquot of that headspace enters a chromatographic system, which separates compounds before detection.

Two common detector approaches are:

• GC-FID: gas chromatography with flame-ionization detection can provide robust quantitative measurement for many organic compounds.
• GC-MS: gas chromatography with mass-spectrometric detection adds spectral information that can strengthen compound identification and help investigate unexpected peaks.

Neither acronym proves method quality. A laboratory still needs appropriate standards, calibration, system suitability, specificity, precision, accuracy or recovery, range, reporting limits, and controls for the actual product matrix. An ethanol-rich liquid, a resinous extract, and a dry leaf powder may behave differently during sample preparation and headspace partitioning.

FDA laboratory methods illustrate headspace GC approaches for particular regulated products, but a hand-sanitizer or sunscreen method should not be copied onto a kratom extract without verification. FDA’s method-validation framework emphasizes that even established methods need verification under the laboratory’s actual equipment, analysts, conditions, and matrix.

A method name is not a complete method record

A COA may say “USP <467>,” “GC-FID,” “HS-GC-MS,” or “in-house method.” Each label supplies only part of the picture.

USP General Chapter <467> is a widely recognized pharmaceutical framework for limiting residual-solvent intake. A reference to it does not show which procedures, analytes, modifications, or product-specific verification were used. It also should not be turned into an unsupported claim that the kratom product is “USP certified.”

An in-house method is not automatically weak. It may be the best fit for an unusual matrix. The important questions are whether the method is documented, scientifically valid for its intended use, appropriately verified or validated, and controlled through routine quality checks.

“Not detected” does not mean zero

Laboratories use several related terms:

• LOD, or limit of detection: a concentration at which the analyte can be detected under stated conditions, though not necessarily quantified with acceptable reliability.
• LOQ, or limit of quantitation: a concentration at which the analyte can be quantified with defined performance.
• Reporting limit: the threshold below which the laboratory reports a result using a convention such as “<RL” or “ND.”
• ND, or not detected: the analyte was not detected under the method’s conditions and reporting convention.

ND does not prove absolute absence. It means the signal did not meet the laboratory’s stated detection or reporting rule in that sample.

Sensitivity must match the specification. If the specification for benzene is 2 ppm but the method’s reporting limit is 5 ppm, an ND result cannot establish that the sample was below 2 ppm. The method can only support “below 5 ppm” under its stated conditions.

Choosing the right solvent panel

A broad catalog panel can be useful, but it is not a substitute for process knowledge. The panel should cover solvents that are reasonably likely to be present because they were:

• used in the final manufacturing step;
• used earlier and not consistently removed by a validated process;
• present as impurities in another solvent;
• introduced by an ingredient, carrier, coating, or flavor;
• used to clean shared equipment and capable of carrying over;
• generated during a reaction or degradation pathway; or
• associated with rework or an unplanned deviation.

The Q3C list is not exhaustive. If a manufacturer uses a solvent not included in the guideline, omission from the table is not permission to ignore it. A qualified toxicological and analytical assessment is needed.

Likewise, a laboratory’s default panel may include chemicals that were never plausible while omitting the one solvent actually used. “Tested for 20 solvents” is less informative than a documented process-to-panel rationale.

How to review a residual-solvent COA in 12 steps

1. Match the product and lot

Confirm the product name, matrix, form, lot or batch number, and any sub-lot designation. A raw extract COA does not automatically release capsules or a flavored finished product made from it.

2. Check the laboratory sample identifier

The laboratory’s sample ID should connect to a chain-of-custody record and the manufacturer’s lot. A missing link makes the report difficult to authenticate.

3. Review the dates

Look for sample receipt, preparation, analysis, report, and any amended-report dates. A test result should not predate the manufacture of the lot it supposedly represents.

4. Identify the exact matrix

The report should distinguish leaf powder, dry extract, liquid extract, capsule blend, or finished packaged product. Matrix drives preparation and method performance.

5. Read the analyte list

Never assume “residual solvents” means every Q3C solvent. Count and name what was actually tested.

6. Compare the panel with the process

Ask whether the listed analytes cover the extraction, purification, reaction, formulation, and cleaning chemicals reasonably likely to remain.

7. Identify the method

Look for a method number and revision, not only an instrument acronym. Determine whether the method was verified for the matrix and the required range.

8. Check units and basis

Confirm ppm, mg/kg, percent, mass/volume, dry basis, or as-is basis. Convert only after the basis is clear.

9. Read each result—not just “pass”

Quantified values, “<LOQ,” and ND convey different information. Preserve the laboratory’s actual notation.

10. Compare reporting limits with specifications

The reporting limit must be low enough to support each specification. This is especially important for low-ppm Class 1 limits.

11. Identify the source of every specification

A result column and a limit column are different things. The COA or quality record should say whether the limit comes from Q3C, a state rule, an internal risk assessment, a customer requirement, or another source—and which version was used.

12. Confirm authorization and amendments

Review the laboratory identity, address, accreditation scope when relevant, authorized signature, page count, and amendment history. Accreditation can strengthen confidence in a laboratory system, but it does not make every method or analyte part of the accredited scope.

Five illustrative COA scenarios

Scenario A: the ethanol-only water extract

A product is marketed as a water extract, yet its COA tests only ethanol. That result may be useful if ethanol was used later as a processing aid, but it does not verify the “water-only” manufacturing claim. The quality reviewer should obtain the process record, identify every volatile chemical, and document why the panel is appropriate.

Scenario B: ND with an inadequate reporting limit

A COA reports benzene as ND. The reporting limit is 10 ppm. The adopted specification is 2 ppm. This is not a supported pass because the method cannot distinguish 3 ppm from zero under that reporting convention. The lot needs suitable evidence at or below the specification.

Scenario C: a single raw-material report for several finished products

A bulk extract passes its panel. The manufacturer then dissolves it in a carrier, adds flavor, fills bottles, and assigns new finished lots. The bulk result remains part of lot genealogy, but it does not address solvents introduced by later ingredients or processing. Finished-product specifications and verification should cover the complete process.

Scenario D: a laboratory changes the method

A new COA uses the same method number but a different revision and a higher reporting limit. Even if every line says pass, quality personnel should evaluate the change. A method revision may affect comparability, trend data, and the ability to support existing specifications.

Scenario E: a concentrated 7-OH product presents a leaf COA

The report identifies ordinary leaf powder and includes microbiology and heavy metals, while the retail product is a concentrated tablet. That COA does not establish the tablet’s residual-solvent profile, alkaloid composition, manufacturing route, or legal status. Kiody does not sell concentrated 7-OH products.

Common residual-solvent COA red flags

Pause and investigate when a report shows any of the following:

1. “Solvent free” with no defined analytical threshold.
2. “Full panel” without an analyte list.
3. A raw-material lot number that does not connect to the finished product.
4. No product matrix or an obviously incorrect matrix.
5. No method identifier or revision.
6. A panel that omits the solvent named in the manufacturing record.
7. ND results without LOD, LOQ, or reporting-limit information.
8. A reporting limit above the adopted specification.
9. Results in ppm compared with a percent limit without a shown conversion.
10. An Option 1 comparison when the maximum daily product mass exceeds 10 grams.
11. A reused PDF with altered product names or cropped page numbers.
12. A report date that predates the lot.
13. A generic leaf COA attached to an extract or enhanced product.
14. A “USP certified” claim based only on a reference to USP <467>.
15. A “FDA approved” or “FDA compliant kratom” claim inferred from laboratory testing.
16. No explanation for an unexpected peak or qualifier.
17. Repeated identical numerical results across unrelated lots.
18. A passing retest presented without the original result or investigation.

One red flag does not always prove misconduct. It does mean the evidence is incomplete and should not be overclaimed.

Supplier qualification and change control

Residual-solvent control is not a once-a-year PDF exercise. A buyer of an extract should qualify the supplier and keep the assessment current.

Useful supplier evidence includes:

• a process flow showing solvent introduction and removal;
• solvent identity, grade, supplier, and specifications;
• finished-material residual-solvent specifications;
• method-validation or verification summaries;
• representative lot data and trends;
• deviation, rework, and change-control procedures;
• qualification of contract laboratories;
• audit responses and corrective actions; and
• written notification requirements for process changes.

Reassessment may be needed after a new solvent or supplier, a change in extraction ratio, a different evaporator or dryer, altered time or temperature, new shared equipment, a laboratory method revision, a facility transfer, an unexpected result, or a complaint involving odor or product consistency.

Retesting should follow a documented investigation. A passing retest does not automatically erase an unexplained original failure.

A proposed 24-field Kiody residual-solvent review record

For internal review, Kiody could retain the following fields for every applicable lot:

1. Product name.
2. Product form and matrix.
3. Finished-product lot number.
4. Ingredient and extract lot genealogy.
5. Supplier name and manufacturing site.
6. Manufacturing-process revision.
7. Complete solvent and volatile-processing-aid inventory.
8. Solvent grades and supplier specifications.
9. Recovered-solvent use and controls.
10. Drying or purge step and critical parameters.
11. Shared-equipment and cleaning-agent assessment.
12. Panel-selection rationale.
13. Laboratory name and location.
14. Laboratory sample ID and chain-of-custody reference.
15. Method number, revision, and detector.
16. Matrix-verification or validation reference.
17. Analyte list.
18. Result and unit for every analyte.
19. LOD, LOQ, or reporting limit for every analyte.
20. Specification and authoritative source for every analyte.
21. Maximum daily product mass used in exposure calculations.
22. Calculated daily exposure where applicable.
23. Deviations, qualifiers, investigations, and amended reports.
24. Quality-review decision, reviewer, and date.

This record is a proposed transparency and quality-control format, not a statement that every field is legally required for every product.

Safer public language

Public-facing quality language should stay within what the evidence proves.

Prefer:

• “This finished lot was tested for the process-relevant solvents listed on its COA.”
• “The COA reports ethanol below the laboratory’s stated reporting limit of X ppm.”
• “The result was reviewed against Kiody’s documented finished-product specification.”
• “Testing is one part of product review and does not establish FDA approval.”

Avoid:

• “100% solvent free.”
• “Zero chemicals.”
• “Passed every possible solvent test.”
• “FDA compliant” when the claim is based only on a COA.
• “Safe” as a conclusion from a residual-solvent panel alone.

Specific, measured language is more trustworthy than absolute language.

Residual solvents and current federal 7-OH rules are separate questions

As of August 30, 2026, the federal action concerning 7-hydroxymitragynine above a specified threshold remains a proposal, not a final scheduling rule. DEA extended the public-comment deadline to September 10, 2026.

A separate temporary order placing mitragynine pseudoindoxyl, MGM-15, and MGM-16 in federal Schedule I took effect on August 26, 2026. DOJ also announced a nonbinding enforcement-discretion position concerning only incidental trace mitragynine pseudoindoxyl in products otherwise consistent with botanical kratom. That position supplies no numerical safe harbor and does not cover intentionally manufactured or concentrated material, MGM-15, or MGM-16.

A residual-solvent COA does not answer any of these composition or legal questions. A product can meet a solvent specification and still contain a prohibited compound, exceed a state threshold, be mislabeled, or fail another quality specification. Conversely, a botanical leaf product should not be described as an extract merely because a laboratory used an organic solvent during sample preparation for analysis.

Kiody is a 21+ business and does not sell concentrated 7-OH.

Frequently asked questions

Does pure kratom leaf need residual-solvent testing?

The answer should follow a documented risk assessment. If no volatile organic solvent was used or reasonably introduced, a manufacturer may justify a different panel from an extract. The evidence should still address supplier processing, sanitation, shared equipment, and any relevant upstream treatment. Pure leaf also needs other product-appropriate testing that a solvent panel cannot replace.

Is a water extract automatically solvent free?

No. Water may be the main extraction medium, but the complete process can include later carriers, processing aids, cleaning agents, or upstream chemicals. “Water extracted” is a process claim that should be supported by records.

Is ethanol a Class 3 solvent?

Yes, ICH Q3C lists ethanol in Class 3. That is a lower-toxic-potential classification within a pharmaceutical guideline, not permission to ignore its identity or level.

What does 5,000 ppm mean?

For a solid reported by mass, 5,000 ppm equals 5,000 mg/kg, 5 mg/g, or 0.5%. The appropriate comparison still depends on the product, daily mass, specification, and reporting basis.

Is “ND” the same as zero?

No. ND means the analyte did not meet the method’s detection or reporting rule in the tested sample. The reporting limit is essential context.

What if the reporting limit is above the specification?

The result cannot demonstrate compliance with that specification. A more sensitive, suitable method or other scientifically defensible evidence is needed.

Is GC-MS always better than GC-FID?

Not automatically. Mass spectrometry can add identification power, while FID can provide strong routine quantitation for many compounds. Method suitability, validation, calibration, reporting limits, and matrix performance matter more than the detector acronym alone.

Does “USP <467>” mean a product is USP certified?

No. It may identify a residual-solvent procedure or framework. It does not by itself establish USP certification, compendial compliance, FDA approval, or product legality.

Can a supplier COA replace finished-product testing?

Not automatically. Supplier results can support ingredient qualification, but later formulation and processing may introduce or change relevant solvents. The manufacturer’s specification and verification plan should address the finished product and the complete process.

Should every product be screened for every Q3C solvent?

Not necessarily. The panel should be based on process knowledge and risk, while still accounting for solvent impurities, cleaning agents, cross-contact, and unexpected changes. A large generic panel can still miss the actual process solvent.

Why does the maximum daily amount matter?

Toxicological limits are often expressed as daily exposure. The same ppm result creates a larger daily exposure when more product is consumed. Q3C Option 1 assumes no more than 10 grams of total product components per day.

Can residual-solvent testing prove that an extract is botanical?

No. It measures selected volatile compounds. Botanical identity, alkaloid composition, manufacturing route, and adulteration require other evidence.

Can it prove a concentrated 7-OH product is legal?

No. Residual-solvent results do not determine 7-OH concentration, total-alkaloid ratios, synthetic origin, scheduled derivatives, age restrictions, or state and local shipping rules. Kiody does not sell concentrated 7-OH.

Can a manufacturer average several solvent results?

Not casually. Each lot result should be evaluated under the approved specification and investigation procedure. Averaging separate lots or testing into compliance can conceal variation and does not automatically resolve a failure.

What is the best single question to ask about a solvent COA?

Ask: “How does this analyte panel connect to the actual manufacturing process for this exact finished lot?” That question links process knowledge, sample identity, method selection, and the final quality decision.

Primary and authoritative sources

1. International Council for Harmonisation, ICH Q3C(R9), Impurities: Guideline for Residual Solvents (Step 4 version dated January 24, 2024): https://database.ich.org/sites/default/files/ICH_Q3C%28R9%29_Guideline_MinorRevision_2024_2024_Approved.pdf
2. U.S. Food and Drug Administration, Q3C Tables and List: https://www.fda.gov/media/71737/download
3. Electronic Code of Federal Regulations, 21 CFR §111.70 — What specifications must you establish?: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-111/subpart-E/section-111.70
4. Electronic Code of Federal Regulations, 21 CFR §111.75 — What must you do to determine whether specifications are met?: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-111/subpart-E/section-111.75
5. Electronic Code of Federal Regulations, 21 CFR §111.320 — Requirements for laboratory methods: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-111/subpart-J/section-111.320
6. U.S. Food and Drug Administration, Botanical Drug Development: Guidance for Industry: https://www.fda.gov/media/93113/download
7. U.S. Pharmacopeia, Residual Solvents FAQs: https://www.usp.org/frequently-asked-questions/residual-solvents
8. U.S. Food and Drug Administration, Foods Program Methods Validation Processes and Guidelines: https://www.fda.gov/food/laboratory-methods-food/foods-program-methods-validation-processes-and-guidelines
9. U.S. Food and Drug Administration, Direct Injection Gas Chromatography Mass Spectrometry Method for the Detection of Listed Impurities in Hand Sanitizers (a product-specific analytical example, not a kratom method): https://www.fda.gov/media/141501/download
10. U.S. Food and Drug Administration, FDA and Kratom, updated December 2, 2025: https://www.fda.gov/news-events/public-health-focus/fda-and-kratom
11. Drug Enforcement Administration, 7-Hydroxymitragynine Above a Specified Threshold in Schedule I; Extension of Comment Period, August 26, 2026: https://www.federalregister.gov/documents/2026/08/26/2026-17409/hydroxymitragynine-above-a-specified-threshold-in-schedule-i-extension-of-comment-period
12. Drug Enforcement Administration, Temporary Placement of Mitragynine Pseudoindoxyl, MGM-15, and MGM-16 in Schedule I, effective August 26, 2026: https://www.federalregister.gov/documents/2026/08/26/2026-17429/schedules-of-controlled-substances-temporary-placement-of-mitragynine-pseudoindoxyl-mgm-15-and
13. U.S. Department of Justice, Justice Department Announces Emergency Scheduling of Three Potent Opioid Compounds, August 25, 2026: https://www.justice.gov/opa/pr/justice-department-announces-emergency-scheduling-three-potent-opioid-compounds