Most conversations about viable air sampling focus on the “headline” specs: flow rate, portability, ease of use, maybe how it fits into an isolator or a Grade A zone.

All important.

But when quality, validation, or an inspector gets involved, the conversation changes very quickly. It becomes less about what a supplier says their sampler does, and more about what they can prove, and how robust that proof is.

That’s where validation at a government-recognised laboratory really matters.

The uncomfortable truth is that “validated” can mean a lot of things

In our industry, you’ll sometimes hear the word validated used loosely.

Sometimes it means:

• “We ran some tests in-house.”
• “We tested it at a friendly lab.”
• “We’ve got a summary slide somewhere.”
• “It meets the standard because we’ve always sold it this way.”

None of that is necessarily dishonest, but it isn’t the same as independent validation carried out under controlled conditions by a lab with formal recognition and a reputation to protect.

And when you’re using the data to support product release decisions, contamination investigations, or regulatory compliance, the difference is huge.

What does a government-recognised lab actually give you?

A government-recognised lab brings three things that are hard to replicate elsewhere:

1) Independence
They are not invested in your product looking good. Their job is to report what the performance truly is.

2) Scientific rigour
Test methods, controls, repeatability, documentation — all done properly, so the results stand up to scrutiny.

3) Credibility under pressure
When questions come (and they do), the validation doesn’t collapse into “trust us”. You have defensible data from an external authority.

That’s not just a compliance tick-box. It’s operational confidence.

What “good validation” looks like in practice

When we talk about validating an active air sampler properly, we mean examining the performance data to answer the questions that matter:

• Does it capture the particle sizes you care about?
  (Often discussed in terms of D50 and collection performance.)

• Does it preserve organism viability?
  It’s one thing to impact microbes onto agar; it’s another to do it in a way that doesn’t damage them so your results become artificially low.

• Is performance consistent over time and across conditions?
  Consistency is what makes a monitoring method usable and trustworthy.

• Is the evidence documented, transparent, and repeatable?
  A report you can put into a validation pack.

And importantly: can you explain it clearly to a quality team, a validation engineer, and (if needed) an inspector?

Why this matters more now than it did five years ago

Aseptic manufacturing has become less forgiving. Annex 1 has pushed the whole industry toward tighter thinking around contamination control strategy, sampling rationale, and data integrity.

That means the tolerance for anything but robust validation is shrinking.

If you’re challenged on why you chose a method, or how you know it performs as claimed, you want answers that don’t rely on internal confidence or historical familiarity alone.

A practical question to ask any supplier

Here’s a simple test that cuts through a lot of noise:

“Can you share the full validation report — and who carried it out?”

Not the brochure version. Not the one-slide summary. The real report.

If the response is vague, defensive, or “we don’t share that”, it’s worth pausing. Because if you can’t see the data, you can’t assess risk properly.

Where slit-to-agar fits into this

One reason we’ve stayed committed to slit-to-agar is that it’s a method that can be validated and understood with clarity.

It’s not a black box. You can test it. You can document it. You can explain it.

And for cleanroom teams who need results that are not only accurate, but defensible, that matters.

Final thought

Validation is not a paperwork exercise. It’s what turns monitoring from “something we do” into “something we can rely on”.

If you’re reviewing your viable monitoring setup, whether you’re in a new build, an isolator project, or simply trying to strengthen your contamination control strategy,

it’s worth putting validation quality near the top of the list.

If you’d like to talk through what good validation evidence looks like (or what to ask for), you know where to find us. We’re always happy to share what we’ve learned.

~ Gethin