Short answer: A chain of custody exists to prove a sample was in the possession of, or secured by, a responsible person from the moment of collection through final analysis or disposal.[1] It's a simple concept that breaks easily on paper — a missing signature, an illegible field, a form that never made it into the sample cooler. For consultancies working with AIHA-accredited laboratories, a broken chain of custody can undermine an otherwise perfectly valid sample.
What is chain of custody, and why does it matter for IH samples?
Chain of custody documentation tracks a sample's possession continuously, from field collection through lab receipt, analysis, and eventual disposal.[1] It exists to answer one question if a result is ever challenged: can you prove nothing happened to this sample that would compromise the result?
- AIHA-accredited laboratories operate under quality systems that trace back to ISO/IEC 17025, the international standard for testing and calibration laboratories.[2][3]
- Accredited labs maintain rigorous documentation control over their own procedures and analyst training — but that rigor only protects a sample once it arrives.[4]
- Everything that happens *before* the sample reaches the lab — labeling, sealing, field-to-lab handoff — is the consultancy's responsibility to document.
Where does chain of custody typically break down?
Almost always on the field side, not the lab side:
- Illegible or incomplete forms — required fields (sample ID, date, collector, analysis requested) filled in inconsistently across a busy sampling day
- Lost or damaged paper forms — a form left in a vehicle, water-damaged in the field, or simply misplaced between collection and shipment
- Handoff gaps — no clear record of who had custody of the sample between the collection point and the shipping courier
- Mismatched sample IDs — a labeling error that decouples the physical sample from its documented chain
Any one of these can force a lab to flag or reject a sample, or force a consultancy to explain a documentation gap during a legal or regulatory challenge — regardless of how clean the underlying data actually is.
What does a complete chain of custody record need?
At minimum, for each sample:
- Unique sample ID matching the physical sample label
- Date, time, and location of collection
- Analysis requested and applicable method
- Name of the person who collected the sample
- Signature and timestamp at every custody transfer point
- Shipping/receipt confirmation from the laboratory
How myIH supports defensible chain of custody
myIH is industrial hygiene field-note software that structures field observations — including custody documentation — at the point of collection.
- Structured, locked fields ensure sample ID, collector, and analysis details are captured consistently and can't be left blank
- Digital records eliminate the illegible-handwriting and lost-paper-form failure modes entirely
- Real-time oversight of what's being logged during a multi-sample collection day
- One-click export to Excel or PDF field notes, so custody documentation travels cleanly alongside the sample
To be clear on scope: myIH structures and exports your team's field-side documentation — it doesn't replace the accredited laboratory's own custody and analysis procedures once a sample is received. It closes the gap on the side of the chain a consultancy actually controls.
Frequently asked questions
Documentation that tracks a sample's possession continuously from field collection through laboratory analysis, proving it wasn't compromised along the way.
On the field side — illegible or incomplete paper forms, lost documentation, or unclear handoff records between collection and shipment.
No. Lab accreditation covers the laboratory's own procedures and analysis; documentation before the sample reaches the lab is the collecting consultancy's responsibility.
References
- "Forms and Documents." AIH Labs, 7 Oct. 2025
- "AIHA Laboratory Accreditation Programs, LLC." AIHA LAP
- "AIHA Certifications: Complete Industrial Hygiene Credential Guide." Employers, 30 Jan. 2026
- "Labs Show Their Credentials." SGS Galson, 7 Oct. 2020
- "AIHA Laboratory Accreditation Programs, LLC | IHLAP Program Requirements." AIHA LAP
Curious how myIH would fit your workflow?
Want cleaner custody documentation for your sampling program? See how myIH structures field-side records.
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