Quick answer
Fit testing is needed when relying on a tight-fitting RPE facepiece to establish that the selected make, model, type and size can seal adequately on the wearer. It must be done competently and does not replace a user seal check each time the device is worn. Reassess changes to equipment or the wearer that can affect fit.
Understand why fit is individual
HSE fit-testing guidance explains that one facepiece or size is unlikely to fit everyone. Leakage around a tight-fitting seal can defeat the intended protection even where the filter is appropriate.
The fit test concerns the actual wearer and selected device. A colleague’s successful result, a product’s protection rating or a certificate for a different mask is not evidence of this person’s fit.
Distinguish fit testing from everyday checking
| Activity | Purpose |
|---|---|
| Competent fit test | Evaluate the selected tight-fitting facepiece on the individual using a suitable test method. |
| User seal check | Check correct fitting each time according to instructions. |
| Condition/maintenance check | Identify damaged, dirty, worn or incorrectly assembled equipment. |
| Selection review | Confirm suitability after relevant wearer, task or equipment changes. |
Passing one check does not remove the need for the others. Test methods and protocols require competent execution; this article is not a do-it-yourself fit-testing procedure.
Assess changes and seal interference
Use the successful make/model/type/size in actual work. Where more than one tight-fitting facepiece is used, each needs appropriate fit assessment. Review changes to facial characteristics, equipment or other items that may affect the seal.
Facial hair in the seal area prevents dependable sealing. Discuss suitable alternatives with competent support where tight-fitting equipment cannot be used, including relevant personal or religious needs; do not simply issue an unsuitable mask.
Choose a competent fit-testing arrangement
Check the tester’s training, experience, method suitability and equipment arrangements. A recognised competence scheme can support the assessment, but the employer must still ensure the service fits the task. Provide relevant information and retain the actual result and equipment identity.
Illustrative example: a site buys a replacement mask that looks similar to the old one. Check the exact identity and fit-test implications before issue. Visual similarity does not extend the old result.
Keep fit within the RPE programme
HSG53 places fit within selection, training, correct use and maintenance. Staff need access to the approved equipment and an escalation route if it is unavailable, uncomfortable, damaged or cannot seal.
Coordinate with the applicable GB/NI framework and competent advisers. A fit-test pass is not a guarantee against every exposure or evidence that source controls are unnecessary.
Next steps
- Identify the actual tight-fitting facepiece and wearer.
- Arrange competent fit testing and record the exact device.
- Train seal/condition checks and address interference.
- Review relevant changes and retain suitable alternatives/escalation.
Read the official practical guidance — Use the current source alongside the procedures for your own business.