Legal provisions and technical rules concerning noise at the workplace

The Noise and Vibrations Occupational Safety and Health Ordinance (LärmVibrationsArbSchV) of 6 March 2007 (Federal Gazette I p. 261), last amended by Article 5, Paragraph 5 of the Ordinance of 18 October 2017 (Federal Gazette I p. 3584), transposes two European occupational health and safety directives into German law: 2003/10/EC, Noise, and 2002/44/EC, Vibration. In order to support the requirements set out in these directives, the Committee on Work Equipment (ABS) has drawn up technical rules (TRLVs) for the areas of "noise" and "vibration". By observing these technical rules, an employer may assume that the corresponding requirements of the ordinance are also met (presumption of conformity).

As part of the risk assessment, the employer must determine whether the workers are or could be exposed to noise. In addition, possible effects arising through reciprocal effects or combination with simultaneous exposure to noise and work-related ototoxic substances or to vibration must be taken into account.

With respect to the assessment of noise exposure, the Noise and Vibrations Occupational Safety and Health Ordinance specifies a number of action values which, when attained or exceeded, trigger a requirement for preventive measures. A daily noise exposure level L_EX,8h of 80 dB(A) or greater or a peak sound pressure level L_pC,peak of 135 dB(C) or greater requires (lower exposure action values):

• The workers to be informed (when the action value is reached)
• Hearing protectors to be made available (when the action value is exceeded)
• Preventive occupational medical care to be offered (when the action value is exceeded)

A daily noise exposure level L_EX,8h of 85 dB(A) or greater or a peak sound pressure level L_pC,peak of 137 dB(C) or greater requires (upper exposure action values):

• Hearing protectors to be worn (when the action value is reached)
• Preventive occupational medical care to be arranged (mandatory, when the action value is reached)
• Noise areas to be signed (when the action value is exceeded)
• A noise abetement programme to be put in place (when the action value is exceeded)

The maximum permissible exposure values are further important variables. These values require that it must be ensured, taking the sound-attenuating effect of the hearing protectors into account, that the noise reaching the workers' hearing does not exceed the values of 85 dB(A) for L_EX,8h and 137 dB(C) for L_pC,peak.

The TRLV technical rules governing noise pursuant to the Noise and Vibrations Occupational Safety and Health Ordinance, latest edition August 2017, support the ordinance with respect to noise. An employer observing these technical rules may therefore assume that he has met the requirements of the ordinance. The TRLV technical rules governing noise apply to the frequency range between 16 Hz and 16 kHz (sound audible to human beings) and are divided into four parts:

• The general section describes the scope of application and the employer's responsibility, and explains the most important terms.
• Part 1, concerning assessment of the hazard arising from noise, describes the principles for performance of an expert risk assessment. Reciprocal effects between noise and vibration and between noise and work-related ototoxic substances are also addressed. Further topics are the instruction of workers and general occupational health advice.
• Part 2, concerning the measurement of noise, describes the performance of noise measurements and interpretation of the results in accordance with the state of the art, and comparison of the measurement results with the action values. Person- and site-related assessment is also explained, as is application of daily and weekly noise exposure levels.
• Part 3, concerning noise control measures, includes explanations of the requirement for exposure to be reduced to the minimum possible and of the hierarchy of protective measures. A number of essential means of reducing noise are described. These include the selection of low-noise machines, constructive measures taken at the source of noise, measures influencing the room acoustics and organizational measures. The selection and use of hearing protectors is also addressed.

The TRLV technical rules governing noise offer practical guidance on many aspects. They explain the procedure for risk assessment and present a measurement method based on DIN EN ISO 9612 for determining the noise exposure level. Specific measures for protection against noise are also described.

Further assistance in determining the noise exposure at workplaces can be found in the noise protection worksheet IFA-LSA 01-400 (in German), on assessment of noise exposure in accordance with the German Noise and Vibrations Occupational Safety and Health Ordinance.

Point 3.7 of the Annex of the German workplaces ordinance (ArbStättV) of 12 August 2004 (Federal Gazette I p. 2179), last amended by section 5 (1) of the regulations of 18 October 2017 (Federal Gazette I p. 3584), requires the principle of noise minimization to be observed, i.e. ‘the sound pressure level in workplaces must be kept as low as possible given the nature of the undertaking’. The sound pressure level is to be reduced, in consideration of the use and the activities to be carried out, to such an extent that the health of workers is not adversely affected. Application was limited to the range below the lower action value of 80 dB(A) specified in the LärmVibrationsArbSchV.

With publication, on 18 May 2018 in the Federal Gazette, of the technical rules for worklplaces ASR A3.7 ‘noise’, support for the requirements of the ArbStättV is now provided. Provided he observes these technical rules, an employer may assume that the corresponding requirements of the ordinance are also met (presumption of conformity).

The technical rules for workplaces ASR A3.7 ‘noise’ were published on 18 May 2018. They set out binding requirements for work premises and workplaces in workspaces for noise levels below 80 dB(A). They define activity-specific limit values for the rating level L_r according to activity categories and at the same time, they set out requirements for the room acoustics of workspaces in consideration of the type of use.

These technical rules are intended to protect the safety and health of workers, particularly against the extra-aural effects of noise. The effects of this exposure are manifested in psychological, physiological and vegetative symptoms, and also in reduced performance. An explanation of the extra-aural effects of noise can be found in Annex 1 of ASR A3.7.

A distinction is made in ASR A3.7 between the three activity categories I, II and III. An activity in this context is purposeful work associated with performance of a task requiring a certain level of concentration or speech intelligibility. An activity can be assessed separately when its cumulative duration over a working day is at least one hour.

• Activity category I requires high concentration or high speech intelligibility; the rating level L_r must not exceed 55 dB(A).
• Activity category II requires medium concentration or medium speech intelligibility; the rating level L_r must not exceed 70 dB(A).
• Activity category III requires low concentration or low speech intelligibility; the assessment rating level must be reduced as far as possible in consideration of noise control measures within the plant/company.

The assessment rating level can be determined with reference to DIN 45645-2.

Room acoustics requirements for the reverberation time T are defined for the octave bands from 250 to 2,000 Hz in consideration of the type of use. Offices are assessed for this purpose in the unoccupied state. Educational premises are assessed in the occupied state, consistent with DIN 18041, type of use A3; the requirement in this case is a reference reverberation time T_ref of (0.32 lg V/m³ - 0.17) s with a tolerance of ± 20%, where V is the room volume in m³. For offices, the following reverberation times should not be exceeded:

• Call centres (offices for communication-based services): T = 0.5 s
• Shared and open-plan offices: T = 0.6 s
• Single and dual-occupancy offices: T = 0.8 s

In line with the TRLV technical rules governing noise, other rooms involving speech communication should achieve either a mean sound absorption coefficient of ᾱ ≥ 0.3 in the octave bands from 250 to 2,000 Hz, or a rate of spatial decay of sound pressure levels per distance doubling DL₂ of at least 4 dB in the octave bands with centre frequencies from 500 to 4,000 Hz in the distance range from 0.75 m to 6 m.