What is personal noise exposure?
Personal noise exposure is a measurement of the amount of noise an employee is exposed to in the workplace. Personal noise exposure is measured using a noise dosimeter.
The requirement for managing the hazard of noise and the prevention of noise induced hearing loss for WA mining employees is clearly outlined in the Mine Safety and Inspection Regulations 1995. WA mine operations have a strict noise monitoring program requiring personal noise exposure results to be submitted to the Department of Mines and Petroleum (DMP) as part of their DMP Noise Report.
As governed by Worksafe WA, and under the Occupational Safety & Health Act 1984, all employers have a legal responsibility to ensure that workers’ exposure to noise is regularly assessed and any hazards managed.
To best assess an individual’s personal noise exposure at work, an Approved Noise Officer takes regular measurements with a noise dosimeter (also known as a personal sound level monitor). The average noise exposure levels of workers during a normal shift can be calculated. These calculations can then be used to manage risk and ensure current noise controls are effective.
Measuring personal noise exposure
The aim of taking a measurement with a noise dosimeter is to evaluate the average exposure of employees to noise during a normal shift or a representative period adjusted for shift length.
The Approved Noise Officer should attach a Class 1 calibrated dose metre to an employee in such a way as to capture noise to which they would be exposed during their shift without being in the way or being where the microphone can be bumped.
Employees should be measured when they are performing their ‘usual’ duties under ‘normal’ work conditions.
Noise dosimeters must comply with the requirements of Australian Standard AS/NZS 2399:1998 and be calibrated at least every two years.
Sample size for personal noise exposure assessments
Noise dosimetry should be undertaken for each role in the workforce. For example, if you have 3 mechanics doing the same work, one ‘dose’ can be taken and used as representative for their role. Taking a number of samples of employees in the same roles and using either the average, or the worst result, can further improve risk management strategies.
Frequency of personal noise exposure assessments
For WA mining operations, each worker exposed to noise above the action level (LAeq85dB) is required to have their noise exposure measured at least every five years. The DMP also expect WA mining employers to submit an annual dosimetry testing program involving at least one fifth of the workforce exposed to noise above the action level.
Mine workers at higher risk due to their level of noise exposure are required to be tested more frequently than every five years.
Testing intervals for different personal exposure levels
|Noise exposure (LAeq,8h) (dB(A))||Noise dosimetry interval|
|Up to 90||Every 5 years|
|90-100||Every 3 years|
|Above 100||Every 2 years|
To find out more about organising a noise assessment or personal noise exposure assessments in Perth or WA, simply get in touch. You are welcome to speak to one of our WA Approved Noise Officers about any questions or workplace scenarios you are unsure about.
Handy noise exposure references
- DMP’s “Guidelines for the Management of noise in Western Australian mining operations“.
- Department of Consumer and Employment Protection’s Procedure for Personal Noise Exposure recordings