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According to the Ministry of Labormore than three million employees are exposed to excessive noise levels in the workplace. Far from being trivial, exposure to noise can have a lasting effect on workers' health. Employers must prevent these risks through risk assessment and the implementation of preventive measures.
Noise in the workplace: what's at stake?
What is noise?
Noise" is generally defined as a set of sounds perceived as annoying by the human ear. This notion remains fairly subjective, since a sound can be perceived differently depending on the person who hears it. But when a sound level exceeds a certain limit, all sounds are considered annoying or even dangerous.
Noise levels are measured in decibels, typically using a sound level meter. The A-weighted decibel, denoted dB(A), takes into account the noise level actually perceived by the human ear. When sound levels are very high, the ear's perception of noise is different. The C-weighted decibel, dB(C), is then used.
For an 8-hour working day, noise exposure is considered dangerous at levels above 80 dB(A). If noise levels exceed this threshold, it is imperative that exposure be of shorter duration. Any exposure, even of very short duration, to noise levels exceeding 135 dB(A) is considered dangerous.
Good to know: noise levels measured in decibels are not directly additive: if one construction machine produces 80 dB(A), two construction machines will not produce 160 dB(A) but 83 dB(A).
Noise: what are the health effects?
The health effects of noise exposure are manifold. They can range from simple hearing fatigue to irreversible deafness caused by destruction of the hair cells in the inner ear. In the most serious cases, a sudden and particularly intense noise can cause the eardrum to tear, resulting in sudden total or partial deafness.
Please note: deafness may be recognized as an occupational disease according to certain medical criteria specified in table n°42 of occupational diseases.
In addition to the risk of hearing damage, exposure to noise also has other effects on the body, including :
- Cardiovascular disorders: numerous studies have highlighted the greater frequency of cardiovascular disorders, particularly hypertension, in noise-exposed workers;
- Sleep disorders : prolonged exposure to noise during the working day has a negative impact on sleep quality, which can lead to chronic fatigue due to poor recovery;
- Stress : insofar as it reduces the ability to concentrate and causes fatigue, noise can be a stress factor, generating dissatisfaction, irritability and even anxiety in exposed workers. The risk ofworkplace accidents is also increased.
Noise at work: what are the employer's obligations?
The prevention of noise-related risks is strictly regulated by the French Labour Code. The rules focus on four main areas: influencing the working environment, assessing risks, implementing preventive measures and monitoring the health of exposed workers.
Prevent noise exposure risks right from the design stage of workplaces
Preventing noise-related risks involves taking action upstream, i.e. from the design stage of the workplace and when choosing work equipment.
On the one hand, noise must be reduced at source , by choosing low-noise or silent machines. It is also important to ensure that premises designed to house noisy work equipment are soundproofed from the outset, in order to reduce reverberation and limit noise propagation to other work areas.
Assess, and measure if necessary, workers' exposure to noise
Noise is an occupational risk factor and must therefore be taken into account when assessing occupational risks. This presupposes :
- Identify the various sources of noise in the plant, according to their nature: machines, tools, ancillary work equipment (ventilation, air conditioning, etc.), mobile machinery, handling of noisy tools by hand, etc.
- Identify all workers likely to be exposed, taking into account non-permanent workers in noisy workplaces (cleaners, etc.).
The risk assessment must then identify the most exposed workstations and the noise sources involved. The results must be transcribed into the DUER ( document unique d'évaluation des risques professionnels ).
To carry out a risk assessment, employers can choose between two methods:
- A summary estimate of the risk based on existing bibliographical data by sector of activity or occupation, and on a noise communication test. If the worker has to raise his voice to make himself understood by a person less than a metre away, the ambient noise level must be considered high and therefore at risk;
- A simplified assessment in cases where daily noise exposure can be broken down into several distinct work phases, or where the work involves an action generating intense but episodic noise.
As soon as a risk assessment reveals a risk to workers' health and safety, the French Labor Code obliges employers to take measurements to check that regulatory noise exposure limits have not been exceeded, and whether or not preventive action is necessary.
Source: Article R. 4431-2 of the French Labour Code
Measurement must enable noise levels to be quantified precisely. Its conditions are set out in an order dated December 11, 2015, which specifies that in the case of high noise levels, measurements must be carried out in accordance with standard NF EN ISO 9612.
Please note: risk assessment and measurement must be carried out by competent persons, with the assistance of occupational health services. Measurement must be repeated at least every 5 years.
Implement preventive measures
Once the measurement results have been obtained, they must be compared with the regulatory thresholds to determine preventive measures. Depending on the nature of the thresholds exceeded, specific preventive measures must be implemented, such as :
Collective protection measures must be implemented as a priority. These can be based on the choice of less noisy work processes, the installation of technical means to reduce noise, or improved work organization to reduce noise exposure (rest periods, limiting exposure time, etc.).
It is important to regularly check the effectiveness of the measures in place. A change in work organization or in the choice of equipment may mean that they need to be adapted to guarantee worker safety.
Medical monitoring of exposed employees
Although noise is no longer one of the occupational risk factors requiring reinforced individual monitoring, the employer may, if he deems it necessary, decide to introduce such monitoring for workers for whom he deems it necessary(article R. 4624-23 III of the French Labor Code).
Workers exposed to noise therefore benefit from standard medical monitoring, including an information and prevention visit (VIP) carried out by a health professional within three months of starting work. This visit must be repeated at intervals of no more than 5 years.
The French Labor Code also stipulates that workers exposed to noise levels in excess of the VAI must be entitled to a preventive audiometric examination aimed at the early diagnosis of any hearing loss and the preservation of hearing function.
Finally, the employer must draw up an annual dematerialized declaration for each employee exposed to noise in excess of the following regulatory thresholds :
- Exposure of at least 600 h/year to a level of at least 81 dB over an 8-hour reference period;
- Exposure to a peak sound pressure level of at least 135 dB for at least 120 times a year.
This declaration enables the employees concerned to contribute to their professional prevention account in respect of arduous work.
Regulatory sources
French Labor Code, articles R. 4431-1 to R. 4437-4 on the prevention of noise exposure risks
Order of December 11, 2015 on the method of calculating physical parameters indicative of the risk of exposure to noise and the conditions for measuring noise levels in the workplace.
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