Listening for life

What is EN 352?

EN 352 is a family of standards, including standards for performance requirements and test methods to cover many types of hearing protectors, including passive and electronic hearing protectors.

These standards are developed by the European Hearing Protection Technical Committee CEN/TC159 and adopted by each EU Member State. They are set by the European Commission and, once published in the Official Journal of the European Union, manufacturers generally meet the standards before placing hearing protection products on the market in Europe.

These standards are based on science and provide a uniform basis for evaluating hearing protection products from different manufacturers. EN 352 certified products undergo independent testing by accredited laboratories and are CE approved by one of our EU Notified Bodies.

As hearing protectors help reduce exposure to harmful noise and are therefore classified in the highest risk Category III within the PPE regulation 2016/425 (EU), they are subject to the mandatory annual audit carried out by a Approved notified body.

This process helps to ensure that products are regularly checked for compliance with the relevant EN standard and EPI Regulation 2016/425 (EU), which gives the user confidence that the product will help to protect against the intended noise risks.

Do you know that EN 352 has been updated?

All published European standards are subject to periodic review every 5 years.

They are reconfirmed over the next 5 years or reviewed based on laboratory testing and field experience to ensure that they remain relevant and reflect current market offerings and/or new technologies, use, etc.

The latest version of the EN 352 standards can be identified by the new publication date, for example EN 352:2020.

For the revised standards, there is an adoption period during which products complying with the previous standards can continue in the supply chain. For the new family of standards EN 352, the adoption period ends on 21 January 2023 and all products submitted after that date must fully comply with the new version of the 2020 standard.

Products manufactured after this date, that is, those that left the factory until January 20, 2023, remain acceptable for use and sales. Please contact your local regulatory or notified body to understand local regulatory or import controls.

Do I have to do anything regarding the EN 352 update?

The action falls primarily on the manufacturer, since all products must be tested, certified and marked with updated standards.

Neither the customer nor the person who buys the product has to do anything.

However, it is recommended that the purchaser verify that products manufactured after 20 January 2023 show the correct year of publication of the standard, e.g. compliance with EN 352:2020 for headgear. The standards referred to can be found in the Declaration of Conformity (DOC) or in the user instructions.

You should also check the product to ensure that it is up to date with any performance compliance changes that may exist, possibly as a result of these updates.

Why is EN 352 being updated?

As indicated above, all harmonised European standards are subject to a mandatory periodic review every 5 years, which is reconfirmed during the following 5 years or amended. In the case of the EN 352 family of standards, the decision taken by the European Technical Committee CEN/TC159 was to revise all relevant parts of this family of standards. One of the main changes in the updated rules was to encourage manufacturers to market products that are more suitable for workers exposed to low to moderate noise levels without insulation or overprotection.

This is the main reason why the minimum octave band test frequencies ranging from 125 Hz to 8 000 Hz have been changed in the conformity assessment.

The new conformity assessment shall be based on compliance with the minimum values for High (12), Medium (11) and Low (9), based on a deviation from the mean of the standard minus 1. In addition to the new conformity assessment, the SNR data are also based on a deviation from the mean of the standard minus 1.

The following table is an example of an octave/HML and SNR table in EN 352:2020.

Are only products with lower attenuations being tested?

No, all products are being retested and recertified to meet new standards, supported by new documentation in the manufacturer's technical report.

Has the test procedure changed?

No, the trial signals, the number of subjects participating in the trial (16) and the way the trial is performed have not changed. However, there is a difference in the calculation and the way of presenting the results.

How is the presentation of the results different?

These mean values and deviations from the norm will be included in both the SNR and HML data. The following table is an example of headphone performance 3M™ PELTOR™ ProTac.

Will this change the performance of the product?

Since Real Ear Attenuation Testing (REAT) is based on a panel of 16 human subjects, there is inherent variability in these types of subjective measurements.

Therefore, even for this same test panel, repeat testing may not produce the same exact values.

Thus, there may be differences in the overall measured values, which are usually within the acceptable tolerance limit for repeatability and reproducibility as indicated in the subjective measurement standard EN ISO 4869-1:2018.

To summarize, even if the product has not changed at all and there have been no changes to the testing procedure, there could still be a change in the performance compliance of the products when testing is performed again.

Check product identification and performance compliances when certification changes to a new standard to ensure that the current performance of the product as assessed in the relevant part of the EN 352:2020 family of standards meets your needs.

How can I find the SNR and HML performance of hearing protection products 3M with European certification?

This information is included in the product user instructions and packaging.

Who should I talk to for more information?

In 3M we have a European team of hearing product and regulatory specialists ready to help you. For more information, please contact your representative 3M local.

You can also consult the updated version of the European guidance document EN 458 on the process of selection, use and maintenance of hearing protection equipment.

Hearing protectors can be divided into two main types: passive and electronic. Within each type, products can vary from earplugs to earmuffs.

Passives

Plugs:e.g. disposable, reusable, semi-insert, banded

Earmuffs:e.g. with headband, neck harness or helmet-mounted version

Electronics

Solution with ear protection:e.g. level dependent plugs

About the ears:for example, two-way communications or wireless communication accessory

Have you found out?

radio communications reduce worker downtime by almost 50%

What should be taken into account whenchoose hearing protection:

> 80 Insufficient
80 to 75 Acceptable
from 75 to 70 Adequate
70 to 65 Acceptable
< 65 Risk of overprotection

Sound attenuation

• The risk of hearing damage is low when the daily exposure level to weighted noise over an 8-hour period is less than 80 dB, and insignificant below 75 dB

• In general, the desirable range of sound pressure level under effective weighted ear protection is between 70 and 75 dB

Need to communicate

• Maintain a balance between speech intelligibility and speech protection

• Consider the need for radio or Bluetooth® mobile phone communications

• A user may not wear hearing protection if they feel isolated.

Work environment

• Take into account physical conditions:

• Whether the noise is continuous or intermittent
• If you need to hear the environment
• Whether protection is required everywhere or in specific locations

Compatibility with other PPE

• When used collectively, the protection of each individual device should not be compromised

Comfort and ergonomics

• If hearing protection is not comfortable, it is unlikely to be worn and the wearer will be at risk.

Fit Check

• To help achieve the desired level of attenuation, hearing protectors should be properly adjusted and tested using an objective or subjective adjustment test system.

Have you found out?

time off due to discomfort, lack of motivation or training may affect overall attenuation.

What can affect the acoustic sealing of an earmuff?

Protective clothing over earmuffs

Respiratory protective equipment

3M strongly recommends fit testing hearing protectors when fitting all accompanying PPE as it is the best method available to validate that each employee is obtaining the appropriate level of protection

Face Shield Head Harness

Headband for glasses

Safety glasses with wide side panels

Have you found out?

some glasses 3M they offer excellent compatibility with earmuffs 3M™PELTOR™ series X

Noise-induced hearing loss is 100% preventable and this makes it extremely important for workers to choose the right type of hearing protection for their environment. With so many options available, it can be difficult to determine which style/type of hearing protection is preferable for each person. Earplugs and earmuffs come in many styles and configurations, including communication earmuffs, so it is even more important to consider the following when choosing which type of protection will be most suitable for each worker.

Determine noise level and environment

According to European Council Directive 2003/10/EC, workers must wear adequate hearing protectors when they reach the upper daily exposure action value LEP, d 85 dB (A). Before considering adequate hearing protection as part of the control hierarchy, an appropriate risk assessment should be carried out to determine the level of exposure of workers within other factors, such as communication, work environment and user preference, for example.

The choice of the right hearing protection for any environment starts here because the selected product must provide adequate protection for the working environment, taking into account insufficient protection and overprotection. Knowing the noise exposure level of workers can help prevent the risk of overprotection, which can potentially lead to a decrease in the audibility of important communication and emergency sounds, such as fire alarms or moving vehicles.

Other environmental factors should be taken into account when choosing hearing protection. These include temperature (extreme heat or cold), humidity, availability of hygiene facilities to insert compressible foam caps with clean hands, thus avoiding any cross-contamination that may be deposited in the ear canal.

Method selection

When choosing hearing protection for workers, it is important to understand and follow the selection methods described in the European guidance document EN 458:2016: Recommendations for selection, use, care and maintenance. Below are the main summary points of the selection criteria of EN 458:2016.

The choice of the appropriate hearing protector should be based on some important criteria, e.g. noise exposure levels, workplace needs for environmental perception and communication or compatibility with other PPE.

• Use the noise exposure data to determine the correct amount of attenuation taking into account overprotection, which may reduce the audibility of important signals, e.g. fire alarms, moving vehicles.
  
  
• Use the octave band, SNR or HML method to estimate the sound level below the protected ear.
  
  
• Use an appropriate fit test method, e.g. FMIRE, to help improve the field performance of a hearing protector.
  
  
• Consider compatibility with other PPE, i.e. earmuffs fitted to protective helmets which must be properly tested and have EC approval according to EN 352-3.

Another important point to consider when choosing hearing protection based on the SNR selection method is that differences of 3 dB or less in the SNR value are usually insignificant. This is because hearing protection attenuation rates are based on subjective human testing methods that include inherent variability, as each test subject is required to respond to audible signals at various test frequencies.

Get to know your workers

Once workplace noise levels are determined, environmental factors are considered, and a selection method is implemented, the other key factor to consider when selecting hearing protection is the worker. It is important to note that, as with other types of personal protective equipment, there is no one-size-fits-all approach to choosing hearing protection.

Training

Employees in a workplace hearing conservation program should receive regular training to ensure they understand how noise exposure affects their hearing and how they should properly select, use, and care for their hearing protection. If workers have not received training on how to properly insert earplugs or how to use earmuffs, they could be at risk of developing noise-induced hearing loss.

Because hearing loss usually occurs gradually, it is important that workers receive ongoing training on the importance of wearing proper hearing protection.

Comfort

It is also important not to underestimate the value of comfort when selecting hearing protection. If hearing protection is comfortable to wear, the worker is more likely to wear it correctly in noisy environments. On the other hand, the worker may remove the hearing protector in the middle of the shift if it is uncomfortable, leaving him exposed to harmful noise levels. Because all ears have different shapes and sizes, 3M it offers a wide range of solutions to better suit individual needs.

Existing hearing loss

Special care should also be taken with workers who already experience hearing loss. It is important to maintain their hearing and at the same time ensure that they can hear critical conversations, workplace alarms, equipment warnings, etc. According to the European guideline document EN 458:2016, people with any medical condition, such as known hearing loss, should be referred to an occupational health professional or an audiologist, for example, for specialist advice.

When hearing protectors are required, the use of sound restoration hearing protectors (level dependent) may be considered appropriate. Normally, these devices are used without placing the hearing aid in the ear, to avoid unnecessary acoustic feedback. Always consult your occupational health professional before using any hearing protector.

Mobility restrictions

Some workers may have difficulty compressing earplugs or using the correct insertion technique due to mobility problems. For example, workers with mobility problems in the shoulder area or those with arthritis in the hands may be affected and may need additional individual training sessions to find a suitable solution. A possible solution to this problem is the style of pressure-adjusting earplugs, which can be inserted into the ear without the need for compression. Earplugs can also be considered a good alternative to help overcome certain mobility problems.

Communication in noisy environments

It is important to balance the needs of workers with the ability to communicate while wearing hearing protection. It is possible to improve communication even in noisy environments. Protective communication devices help to improve safety and productivity and reduce the risk of hearing loss. For example, an earpiece with a built-in ambient microphone allows for face-to-face conversations. and a better perception of the workplace environment. These solutions also work with radio systems.

Fit test

When the above factors are taken into account, it increases the likelihood that workers will correctly use the hearing protection necessary for their environment. However, it can be difficult to accurately measure the amount of hearing protection each worker receives from their hearing protector. An objective way to measure the fit of earplugs or earmuffs is to fit test workers to determine their personal attenuation rating (PAR). Fit testers can also help identify patterns and problem areas, as well as establish an optimal time for individual training, helping to facilitate improvements.

Personal preference

Limiting hearing protectors to a single model will not address the needs of all workers. Because we all have a different shape and size ear canal, offering a selection of different types of hearing protectors will help the user select the type best suited to their individual needs and work environment, taking comfort and compatibility into account. with other personal protective equipment.

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The validation system can be used for both ears 3M™ E-A-Rfit for fit testing earplugs and earmuffs 3M in order to help select the right hearing protector for each worker and their work environment. The test itself is quick, easy and objective, with clear and accurate results. Workers can pass or fail and their personalized attenuation rating will be displayed at the end of the test, indicating their level of protection.

If a worker does not pass the fit test, the company has the opportunity to take immediate action: to provide the worker with training on appropriate fit techniques or to choose a device that provides a better fit.

LIST OF BOOKS

13M Hear for Life - EN 352 Guidance Document - Spanish

2What kind of hearing protection suits your needs?

3Listen for life - Infographic

4Factors to consider when choosing hearing protection.