Safe Noise Levels at Work
The National Work Health and Safety Regulations state that workplace noise exposure levels must be limited to 85 dB(A) and LC,peak of 140 dB(C), in accordance with AS/NZS 1269.1:2005 Occupational noise management – Measurements and assessment of noise immission and exposure.
Workplace Noise Testing Methods
To determine if workplace noise levels exceed exposure limits a noise consultant will first undertake a preliminary noise assessment. The aim of the preliminary noise assessment is to document sources of noise in the workplace and determine the nominal noise levels.
If noise levels in the workplace may be greater than 80 dB(A) then a detailed noise assessment is required.
A detailed noise exposure assessment is undertaken by a qualified noise consultant who has a degree in Science, Engineering or Occupational Hygiene, using equipment calibrated by a NATA accredited facility. The detailed workplace noise assessment assesses the likely noise exposure over an eight hour equivalent working day. There are two methods to calculate the daily workplace noise exposure:
• Noise contour mapping; or
• Individual assessment of noise exposure.
Noise contour surveys measure the noise levels of the area and document the noise levels produced by machinery, which can then be used to determine the overall workplace noise exposure.
Individual Noise Testing Methods
The individual noise assessment may use two methods. One method is by a task analysis, identifying all the tasks that contribute to the overall workplace noise exposure, measuring the noise level and calculating the overall cumulative noise exposure expressed in Pa2. Alternately noise monitoring using personal dosimetery includes placing noise monitors on the worker, which logs the total noise exposure during the day to assess unsafe or safe noise levels at work.
If workers are exposed to excessive levels of noise in the workplace then control measures are required to reduce the total workplace noise exposure to be less than LAeq, 8hr of 85 dB(A) and LC,peak of 140 dB(C). These measures may include controlling noise levels at the source, personal hearing protectors, noise refuges and barriers and administrative controls. Health monitoring is also required at a maximum of two yearly intervals by conducting hearing testing and assessments through audiometric testing.
Further Information on Noise in the Workplace
If you require further advice on workplace noise levels, assessments or noise testing to help you provide safe noise levels at work, please contact our team to speak with one of our noise consultants or occupational hygienists.