Noise can cause permanent hearing loss and lead to stress. A high level of noise also increases the risk of accidents.
Noise in the workplace must be reduced if there is a risk that the noise will exceed certain limits in order to protect the hearing of employees and improve their safety.
Lower exposure action value is 80 dB(A)
If noise cannot be reduced at the source, the employer must provide employees with hearing protection and especially if the noise is at the lower exposure action value.
The employer shall also ensure that employees receive information and appropriate training to prevent noise and to carry out work safely. Employees shall have access to a hearing test if the risk assessment indicates that their hearing is endangered and the noise is above this limit.
Upper exposure action value is 85 dB(A)
If noise in the workplace is at or above the upper exposure action value, it is mandatory to use hearing protection as personal protection. The employer provides hearing protection and informs employees that hearing protection is obligatory in the workplace or in certain areas.
It is important to inform and remind employees about the use of hearing protection with signs or graphically. The employer shall take measures to reduce exposure below the defined limits, take technical and organizational measures based on risk assessment to reduce noise.
Where noise is above the upper exposure action value, employees are entitled to a hearing test.
The exposure limit value is 87 dB(A)
In no circumstances may the noise around employees exceed 87 dB(A) on average during an eight-hour working day.
When evaluating thresholds, it is taken into account whether or not employees use hearing protection.
This limit is set, among other things, to ensure the right choice of hearing protection and other prevention.
If the use of hearing protection has been defined in the workplace or for certain tasks or the noise exceeds the limit, employees should use hearing protection in addition to trying to reduce noise as much as possible and promote that the measures taken to reduce noise are beneficial.
External noise - lower limit value
Limits values for external noise in quieter workspaces are lower and depend on the operation. In control rooms, supervision rooms and other places where it is important for conversations to take place, external noise should not exceed 65 dB(A) on average during an eight-hour working day.
In dining rooms and cafeterias, external noise must not exceed 60 dB(A) during use. In offices and other places where high demands concentration is required and conversations should take place unhindered, external noise should not exceed 50 dB(A) on average during an eight-hour working day.
If noise exceeds this limit, it is important to find the source of the noise and try to take measures to eliminate it with sound attenuation or other design so that sound exposure is not created in the workspace.
It is best to reduce noise at the source. The closer a solution to a noise problem is to the noise source, the better the solution is considered to be. Therefore, the best solution is to prevent noise from occuring. Then you work your way away from the noise source towards those who are exposed to unwanted noise.
Solve the problem at the source of the noise, for example by fixing or lowering engine noise
Cover the noise source
Partitions
Reduce reverberation time – Reduce echoes
Shorten the presence of employees in noise – the organization of work
Hearing protectors – these are emergency measures that are used while looking for other solutions
As soon as work that may cause hearing damage begins, the employer or his representative is obliged to ensure that employees wear hearing protection. This means that even working at noise levels of less than 85 dB(A) may require the use of hearing protection.
There are two types of hearing protection:
Earplugs, which are placed in the ear canal
Earmuffs, that cover the ear
Hearing protection is not a permanent solution to a noise problem. Efforts shall be made to reduce noise at its source.
The employer shall ensure that:
Employees receive appropriate hearing protection, which do not cause discomfort
Employees receive instructions on how to use the hearing protection and information on the danger of not using them. The instructions should relate to the use/optimization, cleaning and storage of the hearing protection.
The hearing protection should be properly maintained
Around and above 80 dB(A)
If the noise level exposed to the employees is 80 dB(A) or the noise is harmful or significantly disturbing, the employer must provide the employees with hearing protection.
It can be in cases such as where very noisy work is carried out for a short time or where there are strong impact sounds. Employees must be provided with hearing protection in such cases, even though the noise level is less than 80 dB(A).
Where noise exposure to workers exceeds 80 dB(A), workers should wear hearing protection. Otherwise, they risk damaging their hearing.
Hearing protection is mandatory above 85 dB(A)
If it is not possible to reduce the noise level on workers below the 85 dB limit, the employer or his representative must only allow the work to be carried out if hearing protection is used.
Dangers due to the use of hearing protection
Hearing protection can make it difficult for workers to talk to each other and thus isolate them from the environment. It must be kept in mind in order to prevent any possible danger due to it. Hearing protectors that reduce the noise much more than necessary can isolate the user and increase the risk.
Earmuffs can cause discomfort due to heat, pressure, skin irritation and rashes. The discomfort can be individual and therefore it is important that staff have the option of different types of hearing protection and can thus choose those that are comfortable but also provide good protection.
The main measurements performed at workplaces are as follows:
Noise Dosimeter Measurements
A microphone is placed as close as possible to the ear of an employee who wears the meter during the working day, or part of the working day. The results of these measurements give a very clear picture of the noise exposure experienced by the employee in question or equivalent noise based on an eight-hour working day, noise peaks and even background noise.
Sound Level Measurements
SLM is commonly a hand-held instrument with a microphone to test noise at certain spots at a specific noise source or at a specific workplace. These measurements are usually short. The meter does not follow the employee, but if the employee has a permanent workstation all day and the noise is relatively equal, a local measurement can indicate the noise that the employee is exposed to.
Frequency Weightings
Frequency weightings are local measurements that measure noise at different frequency ranges. These measurements are done to determine if it is a high-frequency or a low-frequency sound usually for finding suitable solutions, because the same solutions for low-frequency and high-frequency noise are not always sufficient.
Reverberation Time Measurements
Reverberation time is an indication of echo. More echo means a longer reverberation time. Echoes are a reverberation of sound, and the noise is amplified by increased echoes and the acoustics deteriorate. Reverberation time measurements are therefore made to assess the acoustics and provide criteria for calculations for improvements.
Service provider
Administration of Occupational Safety and Health