Key takeaway
A result needs its sample history. Preserve missing custody intervals and method-specific review decisions instead of cleaning them into an apparently complete chain.
Read the sample history before the result
A result table can preserve a number and a laboratory identifier while losing the history needed to interpret that number. Ask whether a reviewer can connect collection, transfer, laboratory receipt, storage, subsampling and the issued report. Custody concerns who held the sample and when; sample condition concerns what happened to it. A signature at receipt cannot fill an undocumented interval or establish every relevant condition during that interval.
EPA’s environmental microbiology guidance describes arrival-condition records, storage, subsampling and sample custody across its lifespan. Its SW-846 holding-time guidance concerns a different environmental analytical context and depends on methods, constituents and matrices. Both were read on 8 October 2026. Use the relevant source within its stated scope; do not combine their examples into a single requirement for every laboratory or every kind of sample.
Make the unresolved interval visible
This hypothetical environmental project retains sample S40, its collection entry, a courier handoff, laboratory receipt and two derived subsample identifiers. The courier record ends at handoff, but the intervening storage record is missing. The laboratory’s project quality lead has not resolved that exception. Result R40 is linked to subsample S40-A and its method version, with the custody question retained as unresolved in the review ledger.
The completed tool identifies what is present without making an unsupported validity judgment. It records the missing interval, the two subsample links and the responsible reviewer. It does not invent a storage temperature, preservation treatment or permissible holding period. No sample is tested in this exercise. The operational decision is to hold any claim that this result has a fully documented history until the method and project requirements are reviewed.
A later document can change only the gap it actually addresses. If the quality lead receives an additional courier receipt, record its date of receipt and the interval it documents. Do not treat it as a storage-condition record unless it contains that evidence. The illustrative R40 review therefore keeps identity, custody possession and handling-condition questions separately visible. The lead can resolve one question while the others remain open, with the issued report and review history still distinguishable.
| Evidence link | Completed illustrative record | Decision or exception |
|---|---|---|
| Collection → S40 | Collection entry and field identifier retained | Origin linked; access review still required |
| Transfer → laboratory receipt | Courier handoff and receipt retained | Intervening storage record absent |
| S40 → S40-A / S40-B | Two subsample identifiers and preparation links retained | Derived identities trace to one original sample |
| S40-A → R40 | Method version and issued result linked | No inference about S40-B’s result |
| Exception → quality lead | Missing interval assigned; review pending | Do not describe custody conditions as complete |
Keep preservation and holding-time judgments method-specific
Locate the method version and the project’s applicable requirements before interpreting collection and analysis times. EPA’s SW-846 guidance explains that preservation and holding-time information varies and that more specific method or program requirements may apply. An archive-wide rule such as “all samples remain valid for this many days” is therefore an unsafe description when the archive contains different methods or matrices.
The records reviewer should preserve the timestamps, stated handling conditions, exception record and quality lead’s determination. This is a documentation task, not a new laboratory validity decision. If a report contains a qualifier, retain its code and the dictionary in force for that report. A cleaned result column that discards qualifiers can make an unresolved exception appear to be an unqualified observation.
Treat a subsample as a linked object
A derived subsample can have its own preparation, storage and analysis history. Retain its identifier and the parent relationship rather than placing all events against the original sample. If one original produces two analyses, do not assume both results share the same subsequent handling or review. The hypothetical ledger links R40 only to S40-A; it does not transfer R40’s interpretation to S40-B.
EPA’s microbiology guidance discusses container identification, subsampling and custody records. For your own archive, confirm which of those records were actually retained, who can interpret their codes and whether attachments remain accessible. A scanned custody form and a structured result export may be separate evidence surfaces. Record their relationship and gaps without claiming that the structured export reproduces every handwritten observation.
Describe the archive around interpretation boundaries
An initial description should distinguish result tables, method dictionaries, custody records, receipt-condition notes and issued reports. Say whether quality review decisions and qualifiers are retained. Avoid promoting the archive as a valid scientific reference simply because all rows have a sample identifier. Actual applicability depends on the method, intended use and the responsible technical review, including unresolved exceptions and the period covered.
Use inventory to list the evidence surfaces and due diligence to ask what a prospective evaluator needs to interpret results. Site identities, sensitive environmental findings, staff details and client-provided materials need scoped review before sharing. A fictional custody ledger can explain the structure without sending actual laboratory records. A separately approved sample or license must specify its own recipients and permitted use; an introductory description does not approve scientific reliance or disclosure.