The following is the information provided in the National Institute of Occupational Safety and Health’s leaflet on the effects of noise in the workplace, which is more dangerous than it may seem at first glance.
What is the noise?
We speak of noise when a set of sounds is considered annoying. It is therefore a subjective concept: the same sound can be considered useful, pleasant or annoying depending on who hears it and at what time; but when the sound level is very high, although in some cases it can be considered pleasant, it can constitute a health hazard.
How many people are exposed to noise at work?
According to the VI National Survey of Working Conditions, in Spain, in 38% of workplaces the noise is annoying, loud or very loud. In 10.5%, the noise is so loud that it is not possible to follow a conversation with another person who is three meters away. The latter situation affects 25% of those working in industry and 22% in construction, which are the most affected sectors.
What does it depend on whether noise is dangerous?
The hazardousness of noise depends not only on its level (which is measured in decibels), but also on the duration of exposure. Spanish legislation considers that when the average noise level during the working day exceeds 80 decibels, the person is legally exposed to noise, and therefore, preventive measures must be taken, which will be increased when the average level exceeds 85 decibels.
In no case-with very few duly justified exceptions-is it permissible for the average level during the whole day to exceed 87 decibels. When the exposure does not last the whole working day, the permissible noise levels increase by 3 decibels each time the time is reduced by half.
What damage can noise cause?
The main damage caused by intense noise is deafness, which is initially temporary but eventually becomes irreversible. It can also cause stress and fatigue, which, in the long run, have consequences for people’s health and for the quality of their work.
Moreover, because noise disturbs communication, makes it difficult to concentrate and distracts attention, it can also contribute to accidents at work.
How do I know if the noise in my workplace is dangerous?
If the risk assessment, which the company is obliged to carry out, shows that your workplace reaches or exceeds noise levels that require preventive measures to be taken, the company must inform you of this and of the preventive measures that will be adopted.
In any case, if you need to raise your voice to talk to a colleague at a distance of one meter, it is likely that the noise level is higher than permitted and, therefore, if this situation is permanent, preventive measures must be taken.
What preventive measures should be taken?
Noise hazards must be eliminated at their source or by modifications to work methods.
One of the most effective measures to reduce noise is to enclose the noisy equipment inside a specially designed booth to prevent it from escaping to the outside. Although the noise reduction afforded by booths is important, it is not always possible to use them, as the enclosure of the equipment may be incompatible with the production process.
By covering the ceiling or walls with absorbent materials, significant noise reductions can be achieved. Sometimes, as shown in the figure, the panels are hung from the ceiling, which allows much larger panel surfaces and thus higher noise reductions to be achieved.
While the above measures are being carried out, or when there is no other means of preventing the risks arising from exposure to noise, individual hearing protectors should be made available to workers. If noise levels exceed certain limits, their use is mandatory.
If the risk assessment reveals the existence of a risk to workers’ health, the employer must carry out health surveillance, which in this case is mandatory for workers.