Noise risk assessment step by step

Legal basis and rules

Under section 3 of the German Noise and Vibration Ordinance (LärmVibrationsArbSchV), the employer must first check, as part of the assessment under section 5 of the Occupational Health and Safety Act, whether workers are or may be exposed to noise. If so, the employer assesses the hazard, determines the exposures and evaluates them. The technical rules TRLV Lärm (version of August 2017) specify this in a general part and three parts: part 1 assessment of the hazard from noise, part 2 measurement of noise, part 3 noise control measures. They apply to the frequency range from 16 Hz to 16 kHz.

The steps at a glance

1. Check whether noise occurs: at which workplaces, machines and activities.
2. Collect information: manufacturers’ noise emission data, publicly available sources, work processes and experience. Typical levels are in the noise levels table.
3. Determine the exposure: with or without measurement, for individuals or whole work areas (DGUV Rule 112-194, section 5.1.1).
4. Compare with the action values: 80 and 85 dB(A) and 135 and 137 dB(C), without counting the hearing protection (overview).
5. Set measures: following the hierarchy, substitution and engineering first, then organisation, hearing protection last.
6. Select hearing protection: so that at most 85 dB(A) and 137 dB(C) reach the ear. The hearing protection finder calculates this.
7. Document and update.

What the assessment must take into account

• type, extent and duration of exposure, including working time beyond eight hours
• the action and exposure values, and quieter alternative work equipment
• findings from occupational health checks
• the effectiveness of hearing protection and manufacturers’ noise emission data
• particularly vulnerable groups
• interactions with vibration and ototoxic substances
• indirect effects, for example when noise interferes with warning signals (warning signals with hearing protection)

Measuring: who, how, how long to keep the results

If compliance with the values cannot be established reliably in another way, measurements are required (section 4). They must meet the state of the art, and methods and instruments must suit the workplace and exposure conditions. Sampling is permitted if it is representative of the person’s exposure. Results must be kept for at least 30 years so that they can be consulted later.

TRLV Lärm describes a measurement procedure based on DIN EN ISO 9612. It rests on a representative working day, described by an analysis of all work phases, breaks and noise-relevant events. Workers with similar exposure can be grouped. How the daily value is derived from the measured values is shown in Calculating the daily noise exposure level.

Who may assess and measure?

The assessment may only be carried out by competent persons (section 5). If the employer lacks the expertise, they must take advice, for example from the company doctor or the safety specialist. Measurements may only be given to persons with the necessary expertise and technical equipment.

Documenting and updating

Documentation is required regardless of the number of workers. It names the possible hazards and the necessary measures. The assessment is updated when working conditions change significantly or when occupational health checks require it (section 3(4)).

EU Directive and UK regulations

• Directive 2003/10/EC, Article 4: the employer assesses noise exposure and measures it where necessary; sampling is allowed if representative; results are stored so that they can be consulted later; the assessment is recorded, kept up to date and revised after significant changes or when health surveillance indicates a need.
• UK, Control of Noise at Work Regulations 2005, regulation 5: from the lower exposure action value the employer carries out a risk assessment, taking into account level and duration, vulnerable groups, interactions with vibration and ototoxic substances, warning signals, quieter equipment and the attenuation of available hearing protectors. The assessment is reviewed regularly, workers or their representatives are involved and the significant findings are recorded.