Top 5 Reasons Your Workers May Be Failing Face Fit Tests

Andrew Gillian

Sat, 04 Oct 2025

At SEI Tech International, it's not uncommon to see customers who are shocked when their employees don't pass a face fit test, particularly when the masks are new or the tasks are routine. The reality is that even the best gear won't save your workforce if they don't fit correctly.

Let's look at it in a bit more detail, why it does this, and what you can do about it. If you're running a construction site, factory floor or healthcare department, these five frequent issues are something that it's worth understanding if you want to get more out of your face fit testing in the UK.

●      Facial Hair Interference

This is the most common reason for failure. Beards, stubble, and even long sideburns will compromise the seal on the mask. The HSE is adamant that tight-fitting respirators demand clean-shaven skin where the mask contacts the face.

Tip: Request workers to be clean-shaven at test time, and explore options such as powered respirators with loose-fitting hoods for workers who can't shave due to religious or medical reasons.

●      Incorrect Mask Size or Model

No one-size-fits-all when it comes to respiratory protective equipment (RPE). One person's perfectly fitting mask may leak on another.

Tip: Carry a variety of models and sizes. When we do face fit testing in the UK, we assist customers in testing several different ones to discover what really fits each face shape.

●      Poor Donning Technique

Even a snugly fitting mask will fail if it is not fitted correctly. Straps that are too loose, nose clips that are not pinched, or hair trapped under the seal can all lead to issues.

Tip: Ensure that workers are instructed on how to properly put on their masks every time, not only for the test. It's a skill, not an isolated incident.

●      Weight Changes or Facial Surgery

Physical facelifts can completely change the fit. If a person has lost weight, had facial surgery, or dental work, their original test won't be accurate anymore.

Tip: Re-test employees if their facial appearance has changed significantly. It's an easy step that can avoid dangerous exposure risks.

●      Damaged or Expired Masks

Employing used-up or damaged RPE on tests can cause failure, despite being okay when new. Cracked seals, worn filters, or elongated straps all detract from protection.

Tip: Check all masks prior to the test. We always advise clients to include simple RPE checks within their everyday safety routine.

Need Help? Contact SEI Tech International

We conduct face fit testing in the UK at SEI Tech International with care, education, and clarity. When your pass rates are low, we're here to help you identify the problem and resolve it. Getting it right isn't about ticking a compliance box. It's a frontline defense.