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According to the Ministry of Labour, more than three million employees are exposed to excessive noise levels in their workplace. Far from being trivial, noise exposure can have long-term effects on workers' health. Employers must prevent these risks by conducting risk assessments and implementing preventive measures.
Noise at work: what are the stakes?
What is noise?
Noise is generally defined as a collection of sounds perceived as annoying by the human ear. This concept remains quite subjective, as a sound may be perceived differently depending on the person hearing it. However, 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 as dB(A), is used to account for the noise level actually perceived by the human ear. When sound levels are very high, the ear's perception of noise changes. The C-weighted decibel, denoted as dB(C), is used in these cases.
For an 8-hour workday, noise exposure is considered dangerous starting at a level of 80 dB(A). If noise levels exceed this threshold, exposure must be kept to a shorter duration. Any exposure, even for a very short time, to a noise level exceeding 135 dB(A) is considered dangerous.
Good to know: sound levels measured in decibels are not additive. If one piece of construction equipment produces 80 dB(A), two pieces of equipment will not produce 160 dB(A), but 83 dB(A).
Noise: what are the health effects?
Exposure to noise has multiple health effects. These can range from simple auditory fatigue to irreversible hearing loss caused by the destruction of hair cells in the inner ear. In the most severe cases, a sudden and particularly intense noise can tear the eardrum, causing total or partial sudden hearing loss.
Note: hearing loss can be recognized as an occupational disease according to specific medical criteria outlined in Table No. 42 of occupational diseases.
Beyond these risks of hearing damage, noise exposure also causes other effects on the body, including:
- Cardiovascular issues: numerous studies have highlighted a higher frequency of cardiovascular issues, particularly hypertension, among workers exposed to noise;
- Sleep disturbances : prolonged exposure to noise during the workday negatively impacts sleep quality, which can lead to chronic fatigue due to poor recovery;
- Stress : by reducing concentration and causing 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?
Noise-related risk prevention is strictly regulated by the Labor Code. The rules are structured around four main pillars: taking action on the work environment, assessing risks, implementing preventive measures, and monitoring the health of exposed workers.
Preventing noise exposure risks from the design stage of workplaces
Preventing noise-related risks requires taking action upstream, that is to say from the design of the workplace, but also when choosing work equipment.
This involves, on the one hand, reducing noise at the source by prioritizing quiet machines or those with limited noise levels. It is also important to ensure soundproofing from the design stage for premises intended to house work equipment that is noisy in order to reduce reverberation and also to limit the spread of noise to other work areas.
Assess, and measure if necessary, workers' exposure to noise
Noise is a occupational risk factor and must therefore be taken into account during the assessment of occupational risks. This requires, beforehand:
- Identifying the various sources of noise within the establishment according to their nature: machines, tools, auxiliary work equipment (ventilation, air conditioning, etc.), mobile machinery, manual handling of noisy tools, etc.
- Identifying all workers likely to be exposed, while ensuring that personnel working non-permanently in noisy workplaces (cleaning staff, etc.) are also taken into account.
The risk assessment must then make it possible to identify the most exposed workstations and the sources of noise involved. Its results must be recorded in the single occupational risk assessment document (DUER).
To carry out the risk assessment, the employer can choose between two methods:
- A summary risk estimate based on existing bibliographic data by sector of activity or profession and on a communication test in noise. If the worker has to raise their voice to be understood by someone located less than one meter away, the ambient noise level must be considered high and therefore risky;
- A simplified assessment in cases where daily noise exposure can be broken down into several distinct work phases or when the work involves an action that generates intense but episodic noise.
As soon as the risk assessment highlights a risk to the health and safety of workers, the Labor Code requires the employer to carry out measurements to verify that the regulatory noise exposure limit values are not exceeded and whether or not preventive actions are necessary.
Source: Article R. 4431-2 of the Labor Code
The measurement must make it possible to precisely quantify noise levels. Its conditions are set by a decree dated December 11, 2015 which specifies that in the event of high noise levels, measurements must be carried out in accordance with the NF EN ISO 9612 standard.
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.
Implementing preventive measures
Once the measurement results are obtained, they must be compared with regulatory thresholds to determine preventive measures. Depending on the nature of the thresholds exceeded, specific preventive actions must be implemented, namely:
Collective protective measures must be prioritized. These may include choosing quieter work processes, installing technical solutions to reduce noise, or improving work organization to limit noise exposure (such as rest periods or limiting exposure duration).
It is important to regularly verify the effectiveness of the measures in place. Changes in work organization or equipment choices may require adjustments to ensure worker safety.
Medical monitoring for exposed employees
Although noise is no longer a professional risk factor requiring enhanced individual monitoring, employers may still choose to implement it for workers if they deem it necessary (Article R. 4624-23 III of the Labor Code).
Workers exposed to noise are generally entitled to standard medical monitoring, which includes an information and prevention visit (VIP) conducted by a healthcare professional within three months of starting the job. This visit must be repeated at intervals not exceeding five years.
The Labor Code also stipulates that workers exposed to noise levels exceeding the upper exposure action values must be offered a preventive audiometric examination to facilitate early diagnosis of hearing loss and protect hearing function.
Finally, employers must file an electronic annual declaration for every employee exposed to noise levels exceeding the following regulatory thresholds :
- Exposure of at least 600 hours per year to a level of at least 81 dB based on an 8-hour reference period;
- Exposure to a peak sound pressure level of at least 135 dB for a minimum duration of 120 times per year.
This declaration allows the affected employees to accrue points in their professional prevention account for occupational hardship.
Regulatory sources
Labor Code, articles R. 4431-1 to R. 4437-4 regarding the prevention of risks from noise exposure
Order of December 11, 2015, regarding the calculation method for physical parameters indicating noise exposure risk and the conditions for measuring noise levels in the workplace.
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