Why Fit Testing

and Fit Checking

guidance is needed for Hearing Protection in the UK

Noise exposure causes permanent and incurable damage to health. Where noise is a workplace risk, an employer in the UK is legally obligated by UK regulation The Control of Noise at Work Regulations 2005 to provide hearing protection devices to at-risk employees and to ensure that the hearing protection device is used fully and properly.

Hearing protection devices must not be used as an alternative to controlling noise by other technical and organisational means, only for tackling the immediate risk while other control measures are being developed to bring noise exposure to below 85 dB (A).

The real-world performance of hearing protection devices will not match the manufacturer's laboratory derived rating. This is an issue that must be managed by duty holders in order to comply with the Regulations. The practice of Fit Testing or Fit Checking hearing protection devices enables a duty holder to address the factors that affect the real-world performance of hearing protection devices.

A range of Fit Testing and Fit Checking approaches are possible and so our team in London have produced this guidance to aid duty holders in their awareness, selection, and application of the different options.

The Problem

The real-world performance
of hearing protection devices

Hearing protection devices fall into two broad categories: earmuffs and earplugs. The real-world performance of both types of hearing protection devices is determined by the following factors:

Factor

Affected by

device workplace wearer
Training
Fitting technique
Compatibility with other equipment
Comfort
Device maintenance
Communication needs
Work being performed
Noise intensity and frequency content
Environmental conditions
Workplace culture
Local policies
Device design
Device noise reduction properties
Device quality

A duty holder must account for these factors when providing a hearing protection device in order to comply with UK Regulations.

A duty holder must also ensure that the hearing protection devices provided have a CE or UKCA mark. To obtain the CE or UKCA mark, hearing protection must be tested and certified according to the EN 352 set of standards. These standards hold hearing protection manufacturers accountable for their products. In obtaining a CE or UKCA mark a hearing protection device receives a single number rating (SNR).

Reliance on the SNR for hearing protection device selection is where the conflict between the expected, and the real-world performance of hearing protection devices originates.

The SNR of a hearing protection device is a laboratory derived average attenuation figure that does not correlate to its real-world performance (HSE, 2009). As such, the SNR cannot be used in isolation to comply with the Regulations.

The SNR is commonly mistaken as representing the real-world performance of a hearing protection device without accounting for the factors that actually affect it. Unfortunately, this means that people working in noise are provided with hearing protection devices that fail to appropriately protect them, either through under-protection (being exposed to the harmful effects of noise) or over-protection (at risk of accidents and injury as a result of reduced situational awareness).

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Fit Testing or Fit Checking hearing protection devices where noise has not yet been eliminated

The Solution

Adopting a fit test approach allows a duty holder to know if the hearing protection being used is providing the required protection. Fit testing can be used as part of a risk management plan while other noise control measures are being developed.

Each Fit Test or Fit Check approach can be assessed based on factors that include:

  • How well it provides knowledge of the real-world performance of the hearing protection device

  • Time required to implement

  • Training required to implement

  • Cost required to implement

  • Equipment required to implement

This introductory guide created by our team in London focuses on fit testing as a tool to address the mismatch between the real-world performance and the manufacturers ratings of hearing protection devices. This enables a duty holder to use this guide to select an approach that best aids them in intervening where noise exposure is a risk caused by the real-world performance of a hearing protection device.

With a focus on addressing the mismatch between real-world performance of hearing protection devices and the manufacturers rating, the following principles can aid the selection of the required approach:

  • Fit Testing or Fit Checking in-the-field is more effective than Fit Testing or Fit Checking in the training room because the training room does not reflect the real-world.

  • Fit Testing or Fit Checking continuously is more effective than temporarily because removing protection for just 2 minutes within the hour (protectors not worn 3% of the time) increases exposure to noise by 400%.

A variety of solutions are available to achieve the different Fit Test and Fit Check approaches. These can be further categorised as being:

  • Performed via a microphone measurement or a hearing test

The following table ranks the different approaches to Fit Testing and Fit Checking by how effectively they can inform the duty holder of the real-world performance of a hearing protection device:

Fit-testing Approach Rank
Fit-Testing in the field with an integrated continuous microphone measurement 1
hearing test
temporary microphone measurement 2
hearing test
with a separate continuous microphone measurement 3
hearing test
temporary microphone measurement 4
hearing test
in a training room with integrated continuous microphone measurement 5
hearing test
temporary microphone measurement 6
hearing test
with additional continuous microphone measurement 7
hearing test
temporary microphone measurement 8
hearing test