ASR 3.7 Occupational Noise Exposure Occupational Noise Exposure
“Noise” in ASR A3.7 includes all sound levels that may endanger the health of employees, including those below 80 dB(A), which impair concentration or mental state.
We often associate the term “noise” with high sound levels. In terms of the ASR A3.7 Occupational Noise Exposure this may also include medium sound levels that may endanger the health of employees. This will include sound levels below 80 dB(A) if they adversely affect concentration and/or mental state. For this reason, there are maximum noise levels for various activity categories that must be adhered to. Since the Noise and Vibration Occupational Safety Ordinance only aims to prevent hearing damage, the ASR A3.7 also addresses the protection from psychological strains caused by noise.
In the Noise and Vibration Occupational Safety Ordinance (LärmVibrationsArbSchV), noise is understood to mean sound that leads to impairment of hearing or other risks for employees. This is the case when a certain sound level is exceeded. A distinction is made between peak sound levels (short-term instantaneous values) and workshift noise exposure levels. The effect of sound (and thus the sensation) on the human hearing generally depends on the level of the sound level. In order to better assess the influence on human hearing, the measured values in the medium level range (up to approx. 60 dB) are evaluated with a corresponding factor (A-weighting). At higher sound levels (> 85 dB), another factor (C-weighting) is better suited to describe the sensation of the ear. While the measurement time for the peak sound levels is short (< 50 µs), the daily noise exposure level is measured over a longer period of time and extrapolated to an 8-hour shift. According to the Noise and Vibration Occupational Safety Ordinance, the employer is obliged to take preventive measures if the daily noise exposure level LEX,8h > 80 dB(A) or a peak sound pressure level LpCpeak > 135 dB(C) occurs.
It is worth knowing that an increase in sound level by 3 dB corresponds to a doubling of sound level. As a result, a reduction in the sound level by (apparently only) 3 dB, e.g. through structural measures, means that the perceived loudness are indeed halved.
While machine manufacturers are obliged to indicate the sound level emitted by the machine, the workplace regulations and the SchallVibrationsArbSchV go further and require employers to determine the total sound level from all sources in the workplace.
Similar to the workplace rules, which specify the workplace regulations, there are the “Technical Rules for the Noise and Vibration Occupational Safety Ordinance (Parts 1-3)” to describe them in more detail.
The regulations mentioned so far only refer to sound levels >80 dB(A), so that only the damaging influences on human hearing are recorded. There are no fixed threshold values for sound levels < 80 dB(A), but only recommendations based on ergonomic findings. For example, the ability to concentrate during predominantly mental activities is already impaired at volume levels below 80 dB(A), so that the noise level must be recorded and evaluated in relation to psychological strain at work even if hearing damage is not expected. For this reason, according to the appendix to Section 3 of the Workplace Ordinance (paragraph 1 under point 3.7)
"...the sound pressure level should be kept as low as possible depending on the type of operation. The sound pressure level at the workplace in work rooms must be reduced to such an extent, depending on the use and the activities to be carried out, that there is no impairment of the health of the employees to be expected. ..."
However, the following common noise level recommendations are widely accepted:
- 35 to 40 dB(A) for very high concentration requirements such as demanding administrative work, programming or scientific work
- 35 to 45 dB(A) during concentrated, predominantly mental work
- 40 to 45 dB(A) if communication with customers is necessary and very good language communication is required
- 40 – 50 dB(A) in call centers and when working with screens in commercial environments
- 45 to 55 dB(A) for routine office work
- 55 dB(A) for predominantly intellectual activities with decision-making and problem-solving tasks, complexity or good speech intelligibility
- 70 dB(A) for predominantly simple or mechanized office tasks, which hardly exist anymore
For newly constructed or retrofitted laboratories , there is a requirement that the sum of all sound levels (e.g. ventilation) at the highest level must not exceed 52 dB(A). Work equipment brought in by users is not taken into account.