FAQ I want to collect samples and do a survey, and just pay a CIH to sign off on the work.
Why a CIH Cannot Sign Off on Samples They Didn’t Collect — And Why That Protects You
In the industrial hygiene world, we get this request more often than you’d think:
“I already took the samples. Can you just look at the lab results and sign off on them?”
On the surface, it sounds simple. The samples are already collected, the lab has done the analysis, and all you need is a Certified Industrial Hygienist to interpret the results… right? Not quite. A CIH’s signature carries legal, ethical, and scientific weight. When we sign a report, we’re certifying that the data is valid, the sampling was performed correctly, and the conclusions are defensible. If we didn’t collect the samples—or directly plan and supervise the collection—we simply cannot make those assurances.
This isn’t about being difficult. It’s about protecting the integrity of the data and, ultimately, protecting you and your people.
Allow me to give you a short course on Industrial Hygiene principles:
Chain of Custody: If We Can’t Verify It, We Can’t Defend It Chain of custody is the backbone of any environmental or industrial hygiene investigation. It is just one part of the air monitoring task it documents:
- where the sample came from - who collected it - how it was handled - how it was transported - when it arrived at the lab
Everyone, regulators, attorneys, and insurance carriers all rely on defensible chain of custody documentation. Without it, the data can be challenged—or dismissed entirely. Further we cannot demonstrate that the tests were conducted correctly. Was the air flow calibrated before and after the the test? Was the sampling media the correct media? Were all the directions in the NIOSH method carefully and completely followed?
If a CIH wasn’t intimately involved in the sampling, we cannot verify any of these steps. And if we can’t verify them, we can’t defend the results.
Sampling Technique Matters More Than Most People Realize Sampling isn’t just “grab a piece of material and send it in.” Proper sampling requires:
- selecting representative locations - using the correct tools and media - avoiding cross contamination - documenting conditions - calibrating equipment - following established protocols (NIOSH, OSHA, ASTM, EPA, etc.)
If any of these steps are missed, the results may be misleading or outright wrong.
A CIH cannot ethically interpret data when the sampling method is unknown or questionable. The ABIH Code of Ethics requires us to ensure that our work is scientifically sound and technically valid. Signing off on someone else’s samples would violate that obligation.
Liability: A CIH’s Signature Isn’t Just a Formality When a CIH signs a report, they are accepting professional liability for:
- the sampling strategy - the methodology - the interpretation - the conclusions - the recommendations
If the samples weren’t collected under our direction, we cannot take responsibility for the outcome. Doing so would expose both the CIH and the client to unnecessary risk.
In other words: If we didn’t oversee the sampling, we can’t stand behind the results.
Context Is Everything Lab results alone don’t tell the whole story. A CIH needs to understand:
- the building conditions - the purpose of the sampling - the history of the space - potential confounding factors - occupant concerns - environmental variables
Without context, even accurate lab results can be misinterpreted. A CIH’s job is not just to read numbers—it’s to understand what those numbers mean in the real world.
Saying “No” Is Actually Protecting the Client When we decline to sign off on someone else’s samples, we’re not refusing to help. We’re preventing:
- invalid conclusions - unnecessary remediation - regulatory problems - disputes with tenants or contractors - wasted time and money
Our goal is always to provide accurate, defensible, actionable information. That’s only possible when the sampling is done correctly from the start.
What a CIH *Can* Do Instead We always offer constructive alternatives:
- perform a proper site assessment - collect new samples under our oversight and direction by our staff. - design a sampling plan tailored to the client’s goals - review the situation and recommend the right approach - provide guidance based on valid, defensible data
This ensures the results are reliable—and that any decisions made from those results are sound.
Integrity First, Always A CIH’s role is to protect health, safety, and scientific integrity. Signing off on samples we didn’t collect would undermine all three. By insisting on proper sampling and documentation, we’re not creating barriers—we’re ensuring that the information you rely on is accurate, defensible, and truly useful.
If you need sampling done right, or if you’re unsure whether previous sampling was adequate, we’re here to help. Reach out anytime and we’ll guide you through the process with clarity and professionalism.
Why Clients Choose DNA
CIH‑Led Expertise - All major projects are overseen by Certified Industrial Hygienists with decades of field experience. Clear, Defensible Reporting - Our documentation is structured for regulatory review, legal defense, and practical decision‑making. Responsive Field Support - We mobilize quickly for urgent needs, including IAQ complaints, water intrusion, asbestos/lead disturbances, and environmental releases. Comprehensive Capabilities - Industrial hygiene, environmental assessment, remediation oversight, and training — all under one roof.
