How to Read Pesticide and Heavy Metal Test Reports for Chinese Herbs

How to read Chinese herb test reports starts with identity: confirm that the product name, botanical name, plant part, product form and batch or lot number match the goods. Then review the laboratory, test method, analyte list, results, units, LOD, LOQ and the acceptance limits applied. Requirements differ by product classification and destination market.

Why Test-Report Review Matters Before Batch Approval

A “pass” statement alone is not sufficient for batch approval. Before a batch is released, the buyer should be able to answer six questions from the document itself:

• Which batch was tested?
• Which analytes were included?
• Which methods were used?
• Which reporting limits applied?
• Which acceptance standard was used?
• Does the report relate to the goods being shipped?

If these details are missing, the report is insufficient for an informed batch-approval decision.

Test-report review sits inside a wider procurement process. For the surrounding supplier-qualification steps, see the bulk Chinese herbs sourcing checklist.

First Check: Does the Report Match the Product and Batch?

Before interpreting the results, confirm that the report belongs to the supplied batch. Compare it against the purchase order, packing label and shipping documents.

Batch-matching steps

1. Compare the commercial product name on the report with the purchase order. The purchase order, packing label and laboratory report may use different trade names, pinyin names or English common names. Confirm that all names refer to the same botanical material.
2. Check that the botanical name is stated in full, including genus and species. Several Chinese herbs may share a similar common name while referring to different species.
3. Confirm the plant part—root, rhizome, flower, fruit, leaf, bark or aerial part. Where a species is traded in several parts, the report must state which part was sampled.
4. Confirm the product form or cut: whole, slices, segments, powder or extract. A report issued for one product form should not be assumed to apply to another form without a documented link between the materials.
5. Match the batch or lot number on the report with the number shown on the packing label and shipping documents.
6. Confirm the supplier identity and the manufacturing or processing site where relevant.
7. Review the sampling, test and issue dates for a plausible sequence relative to the document type and batch history.
8. Confirm how the sample was drawn where that information is available. A result describes the submitted sample; representativeness depends on the sampling plan.
9. Record the sample number together with the purchase order or shipment reference against which the report is accepted.

Differences are not automatically evidence of a defective or falsified document. Trading structures, separate processing sites, translated names and internal lot conventions can all produce legitimate variations.

Any mismatch requires clarification and supporting records before approval.

Key Fields on a Pesticide or Heavy Metal Test Report

Not every report contains every field, and not every field is required for every product. The table below separates fields that should normally be present from those that are useful or context-dependent.

Understanding ND, LOD, LOQ and Reporting Limits

These four terms carry much of the interpretation risk in a contaminant report. Definitions of detection and quantitation used in regulatory analysis are set out in the EPA detection and quantitation procedures documents.

ND / Not Detected

ND normally means that the analyte was not detected above the stated detection limit of the method used on that sample.

It does not mean absolute zero, and it describes only the sample tested.

Read every ND entry together with the applicable LOD or reporting limit. Where these values are not printed, request them before accepting the result.

LOD

The limit of detection concerns detection only. It is the lowest concentration at which the method can distinguish the analyte from background under the stated conditions.

A signal at or near the LOD may indicate detection, but it is not a reliably quantified result and should not be compared numerically against an acceptance limit.

LOQ

The limit of quantification is the lowest concentration that can be quantified with acceptable performance under the stated method and matrix.

Results at or above the LOQ can be compared numerically against an acceptance limit. Results between the LOD and LOQ may be expressed as “<LOQ” rather than as a precise numerical value.

Reporting Limit

The reporting limit is the threshold the laboratory applies when issuing results.

It may sit at the LOQ, above it or follow the laboratory’s internal reporting policy. It is not always identical to the LOD or LOQ.

Where a report uses “<RL,” ask how the reporting limit was derived and whether it was validated in the same matrix as the supplied product.

Why Detection Limits Matter

An ND result is useful only when the reporting capability is low enough for the requirement being evaluated.

If the applicable limit sits below the laboratory’s reporting limit, the report cannot demonstrate conformity with that limit, regardless of how many ND entries it contains.

Reporting limits may also vary between analytes in the same report, so buyers should check them at analyte level rather than relying on one general statement.

How to Review a Pesticide Residue Report

Use the following process when reviewing a pesticide residue report:

1. Confirm that the full pesticide analyte list is attached, not only a summary line or group heading.
2. Identify whether a multi-residue screen or a limited targeted panel was used, and review the stated coverage.
3. Establish which compounds were excluded, particularly substances associated with the crop, growing region or buyer specification.
4. Check the method reference for each analytical group. One report may combine several analytical techniques.
5. Confirm that results are reported individually for each analyte rather than combined into a general category.
6. Check that units are stated and used consistently throughout the analyte table.
7. Confirm that the LOD, LOQ or reporting limit is stated and sufficiently low for the applicable requirement.
8. Identify which MRL, regulation, monograph or buyer specification was applied to each result.
9. Verify that the commodity classification used by the laboratory fits the way the product will be imported and used.
10. Confirm that the report carries the correct batch number for the goods being shipped.

A multi-residue panel does not automatically cover every pesticide. Coverage depends on the method scope and on which compounds the technique can detect in the relevant dried botanical matrix.

Some substances require dedicated single-residue methods and may be excluded from general screens by design.

A statement such as “pesticides passed” is not sufficient for buyer review without:

• The analyte list
• Test methods
• Individual results
• Units
• Reporting limits
• Applicable acceptance limits

Screening and quantitative results are also not equivalent.

A screening result indicates whether a compound appears above a screening threshold. Confirmation and reliable quantification may require an additional analytical step. Where a report contains both screening and quantitative results, check how each result has been classified.

EU pesticide MRLs are substance- and commodity-specific, and the correct value depends on the commodity code applied.

Not every Chinese herb falls under the herbal-infusion category. The same botanical species may be classified differently depending on its intended use and how it is placed on the market.

The EU Pesticides Database is a practical search tool for locating current values, but legally authoritative information is published through official EU legislation on MRLs.

How to Review a Heavy Metal Report

For elemental contaminants, check:

• Which elements were tested
• Whether numerical results are provided for each element
• Which units are used
• Which analytical method was applied
• Which detection or quantification limits were achieved
• Which acceptance limits were used
• Whether the report matches the relevant batch

Lead, cadmium, arsenic and mercury are commonly reviewed for herbal materials. General background on these contaminants is published by the FDA on environmental contaminants in food.

However, the correct element panel is not universal.

Copper, nickel, chromium or other elements may also be required where the selected framework, identified product risk or agreed specification calls for them.

An element absent from the report has not been assessed by that report; its compliance has not been demonstrated.

Method information also matters.

ICP-MS, ICP-OES and atomic absorption techniques differ in the detection capability they can achieve. Sample preparation, particularly the digestion procedure, can also affect recovery.

Mercury may be prone to loss during sample preparation and is sometimes determined using a dedicated method. Where several elements appear under one method reference, confirm that the stated method covers all of them.

Numerical results are useful for comparing batches and monitoring trends.

ND results can also support review, but only when the stated detection or reporting limit is sufficiently low for the applicable requirement.

Total Arsenic vs Inorganic Arsenic

Total arsenic and inorganic arsenic are not interchangeable.

Total arsenic reports all arsenic species present. Inorganic arsenic reports only the species that some frameworks assess separately.

A total arsenic result cannot be read as an inorganic arsenic result. Similarly, a total arsenic figure above a limit expressed specifically for inorganic arsenic is not, by itself, evidence of failure against that limit.

Arsenic speciation is not required for every product.

Check whether the selected framework or agreed specification calls for it. Where speciation is required, confirm that the analytical method distinguishes arsenic species rather than reporting only a total value.

Which Standard Applies to the Report?

Product classification determines which framework applies.

The same botanical material may be treated as a food ingredient, supplement input or medicinal raw material depending on how it is imported and used.

Confirm the classification with the importer’s QA or regulatory team and check that the framework named on the report applies to the intended use of the product.

Accreditation to ISO/IEC 17025 concerns laboratory competence and management systems. It does not set contaminant limits, and it does not by itself confirm that a particular method falls within the laboratory’s accredited scope.

This article is not legal advice.

COA vs Third-Party Laboratory Report

The distinction is between what is required, what was measured and who measured it.

A specification defines requirements. A batch COA records findings for one lot. A third-party report adds independence, but it must still match the batch and use a method suitable for the analyte and matrix.

Accreditation does not mean that every method offered by a laboratory falls within its accredited scope.

For the certificate structure itself, see the Certificate of Analysis buyer guide.

Common Problems Buyers Should Clarify

A report can appear complete while still containing issues that require clarification:

• A general “pass” or “compliant” statement is provided without supporting analyte-level data.
• The reporting limit is higher than the acceptance limit, meaning that an ND result cannot demonstrate conformity.
• The commodity classification used does not match how the product will be imported and used.
• The pesticide panel does not cover compounds required by the buyer specification or relevant product risk.
• Laboratory accreditation is cited without the scope entry covering the method used.
• An earlier report is presented in support of a later production lot.
• Report pages are missing, or an amended version circulates alongside the original without clear revision control.
• Documents within the same batch file cite different standards or limits for the same analyte.

Each issue requires clarification and supporting evidence from the supplier.

None is automatic proof of non-compliance, document falsification or misconduct.

Buyer Report-Review Checklist

• Product name matches the purchase order
• Botanical name is stated in full
• Plant part and product form are identified
• Batch or lot number matches the supplied goods
• Laboratory name and address are stated
• Relevant accreditation scope is provided where accreditation is claimed
• Test method or method reference is stated
• Full pesticide analyte or element list is included
• Results are numerical, or ND is clearly defined
• Units are stated and consistent
• LOD, LOQ or reporting limit is stated
• Applicable acceptance limit or specification is named
• Report is complete, including all pages and amendments
• Report carries an authorized approval

Copyable Document Request Template

Subject: Batch test documentation request – [Product] / Batch [Batch number] / PO [PO number]

Dear [Supplier contact],

We are reviewing [Product], [Botanical name], batch [Batch number], for import into [Destination market] under PO [PO number].

Please provide the following documents and information for this batch:

1. A batch-specific pesticide residue report, including the full analyte list, method reference, individual results with units, and the applicable LOD, LOQ or reporting limit.
2. The MRL, regulation, monograph or specification against which the pesticide results were assessed, together with the commodity classification used.
3. A batch-specific heavy metal report, including the elements tested, numerical results with units, analytical method, and detection or quantification limits.
4. Confirmation that the batch number shown on both reports matches the goods to be shipped under this purchase order.
5. Where laboratory accreditation is stated, the relevant scope entry covering the methods used.

Please also confirm the expected timing for providing these documents.

Best regards,
[Name]
[Company]

Frequently Asked Questions

1. What does ND mean on a pesticide or heavy metal test report?

ND means that the analyte was not detected above the detection limit of the method used on the tested sample. It does not mean absolute zero and applies only to that sample. Request the applicable LOD or reporting limit and confirm that it is sufficiently low for the requirement being evaluated.

2. Is a supplier COA enough, or should buyers request a third-party report?

A batch-specific supplier COA may support routine release where the data is complete and traceable to the lot. An independent report adds external verification for higher-risk products, new suppliers or audited supply chains. Buyers should define these requirements in the quality agreement rather than deciding only at shipment.

3. Do all Chinese herbs use the same pesticide and heavy-metal limits?

No. Pesticide MRLs are substance- and commodity-specific, while elemental contaminant requirements differ between food, supplement and medicinal frameworks. The same botanical species may fall under different requirements depending on how it is imported and used. Confirm the product classification before applying any published limit.

4. How can buyers tell whether the correct MRL or standard was used?

The report should name the regulation, monograph or specification applied and identify the commodity classification used. Compare that classification with the product’s intended market use. Where an EU MRL is cited, verify the value against official EU legislation rather than relying only on a secondary summary.

5. What is the difference between LOD, LOQ and reporting limit?

LOD concerns detection, LOQ concerns reliable quantification, and the reporting limit is the threshold the laboratory applies when issuing results. These values are not necessarily identical. Ask how the reporting limit was derived and whether the method was validated for the same type of product matrix.

6. What should buyers do when the report batch number does not match the shipment?

Request clarification and supporting records before approval, such as production records, sampling records and batch traceability documents. A mismatch may result from relabelling, translation or an internal numbering convention rather than misconduct. Do not approve the batch until the link between the report and goods is documented.

Request Batch Testing Scope and Documentation

Testing scope and accompanying documents are agreed per order according to the product, batch, destination market and confirmed order scope rather than supplied as one fixed package.

Testing arrangements are described on the pesticide and heavy metals testing page, with batch checks outlined under in-house laboratory and quality control process.

To discuss requirements for a specific order, please provide:

• Product name and botanical name
• Product form
• Batch or sample information
• Destination market
• Required pesticide panel
• Required elements
• Applicable specification
• Documents required with the shipment

Discuss Batch Testing Requirements