The prevention of noise-related risks in enterprises, e.g. industrial, is necessary to meet the regulations in force :
- within the boundaries of the concerned site, to protect working personnel, i.e. by ensuring that the sound limit levels in force are not exceeded. In this area, the European directive 2003/10/CE is not intended to apply in all countries, however, the acoustic indicators considered, which are on the one hand the level of daily exposure to noise [1] and on the other hand the peak acoustic pressure [2], are of frequent use, even at the ends of the world (as long as the health of the employees is a concern), despite the maximum authorized values and subsequent actions different may be considered. Standards, sometimes of only national use, and which are not - for the most part - compulsory even in their country of origin (however being a useful reference), mention often more restrictive limits depending on the nature of the tasks performed by employees [3]. The acoustic quality of buildings plays a role, and their soundproofing performance is sometimes regulated - as in France - e.g. in terms of the decrease in sound level by doubling the distance from the source (measured in the empty room of any machine or production facility, or after their installation) [4] or is the subject of normative recommendations [3].
- outside the limits of the concerned site (i.e. at the property line and beyond), so as not to disturb neighbors i.e. by ensuring that the admissible limit in terms of sound levels are respected. In this regard, if the French regulations do not always constitute an example followed to the letter in other countries, the acoustic indicators considered, which are on the one hand the sound pressure level [5] and on the other hand the emergence i.e. the difference between the A-weighted equivalent continuous pressure levels of ambient noise (enterprise e.g. industrial in operation) and residual noise (in the absence of noise generated by enterprise e.g. industrial, but measured over its period of operation) [6], always form the basis of the impositions, possibly with variations as to the values to which one must comply in specified locations. This does not only concern establishments classified for environmental protection (ECEP), but all businesses, craft and commercial activities.
The noise-related risks in enterprises e.g. industrial, are of different kinds :
- within the limits of the concerned site
- for company employees: they can have (very) bad working conditions which can sometimes put them in serious difficulty for the proper performance of their tasks in relation to fatigue, stress, concentration problems; they may not clearly hear what is said to them by co-workers and their supervisors, be in danger if they do not perceive audible warning signals (e.g. security alarms, vehicle horns) in addition to suffering from an alteration in their hearing health
- for the company: it is exposed to the consequences of such poor working conditions (drop in the work quality and/or performance, absenteeism, turnover, difficulties in filling positions) in addition to the costs (direct and indirect) linked to work accidents, and in some cases to proven occupational deafness
- outside the boundaries of the concerned site (i.e. at the property line and beyond)
- for residents: they may experience noise pollution preventing them from fully enjoying their garden (or their balcony), have various psychosomatic disorders (not only sleep disorders)
- for the company: it is exposed to the consequences of such neighborhood disturbances: complaints, legal proceedings, non-authorization of commissioning or administrative closure (as the case may be), with which there are associated costs (direct and indirect) being various (legal costs, operating losses - and in some cases: penalties for late delivery in the event of production interruption -)
The prevention of noise-related risks in enterprises e.g. industrial, is therefore desirable when one wishes to avoid having to face - sooner or later - serious difficulties of all kinds, the common point of which will be to negatively impact the profitability of the activity.
In this area ITS can intervene in different contexts :
- on-site measurements, for the determination of acoustic indicators related to employee noise exposure and acoustic quality of buildings and workplaces or for the assessment of noise levels in the environment
- recommendations for noise reduction (e.g. based on predictive acoustics calculations with simulation software)
- marketing of products and works in terms of sound insulation and reduction of reverberation in premises
ITS participated in the prevention of noise-related risks in an industrial enterprise.
It was about an electricity production plant in Southeast Asia, for which the soundproofing work focused on various noisy equipment (turbines, generators) of a gas power station with a power greater than 1,700 MW.
Soundproof buildings with ventilation systems equipped with silencers, noise barriers (all: in the form of high-rise, demountable metal constructions) have been marketed by ITS, in order to protect site workers and neighbors.
Of course, the site conditions (snow, wind, seismic risks) were taken into account for the mechanical dimensioning (respecting international calculation rules) of this sound insulation equipment of which the complete design and fabrication were integral parts of the contract.
There is no doubt that those constructions will give satisfaction, like many others, similar, delivered - around the world - to a major player in the energy market as part of the prevention of noise-related risks in industrial enterprises.
[1] according to European directive 2003/10/EC, for the daily noise exposure level L EX, 8h: 80 dB (A) and 85 dB (A) are the thresholds, respectively lower and upper, triggering the action; 87 dB (A) is the authorized limit value
[2] according to European directive 2003/10/EC, for the peak sound pressure ρpeak: 112 Pa ie 135 dB (C) and 140 Pa ie 137 dB (C) are the thresholds, respectively lower and upper, triggering the action; 200 Pa i.e. 140 dB (C) is the authorized limit value
[3] e.g. cf. NF S 31-080 Acoustics - Offices and associated spaces - Levels and criteria of acoustic performance by type of space (2006)
[4] in France the Decree of August 30, 1990 is issued for the application of article R. 235-11 of the labor code and relating to the reverberation control of work premises
[5] in France, a limit is set by a prefectural decree e.g. 60 dB (A) at the property line
[6] in France, the emergence is legally limited - depending on the case to 5 or 6 dB (A) during the daytime and to 3 or 4 dB(A) during the night period in regulated emergence areas (REA)