Document ID: chunk:federal_register_of_legislation:F2016L00426:reg:0:p2
Version: federal_register_of_legislation:F2016L00426
Segment Type: reg
Provision Reference: reg 0 (pt 2/20)
Character Range: 27311–30063

done will depend upon:
    * the type of workplace
    * the number of persons potentially at risk from exposure to hazardous noise
    * the information already available on noise at the workplace.
A noise assessment should be done during a typical working shift and should determine:
    * the noise levels produced during various tasks carried out during the shift
    * how long your workers are exposed to noise during each of these tasks.
An assessment should take into account:
    * plant, equipment and other sources of noise in operation at the workplace
    * how work activities are carried out
    * the length of the shift
    * environmental factors (e.g. types of walls, surfaces, layout of work stations).
This means that adequate information about the tasks and their frequency is needed, so consultation with workers and their supervisors is essential.
Noise measurements should be taken at 0.1 to 0.2 metres from the worker's ear canal entrance over a period of time that is representative of the noise produced during the tasks.
In most situations the use of a hand-held integrating sound level meter will produce the most useful information for choosing appropriate noise control measures. In situations where workers are highly mobile or access for the person taking the measurement is difficult or unsafe, it may be more appropriate to use personal sound exposure meters (dose meters).
Noise measurements should include the combined noise levels of all the tools, machines and processes present as well as the background noise from ventilation systems, cooling compressors, circulation pumps, etc. To identify which noise sources contribute most to workers' exposures, the noise from each source or work activity should also be measured separately.
The Ready Reckoner in Appendix C may be used to work out the total LAeq,8h for combinations of noise levels and exposure duration for each work activity and the relative importance of each.
If a group of workers is exposed to identical sources of noise and their exposure is likely to be the same, then you do not need a separate assessment for each worker. A representative assessment can be done for one or more of the workers.

Extended work shifts
Shift durations of 10 hours or longer involve a degree of risk greater than that indicated by the 8 hour measurement LAeq,8h. This increase in risk arises because of the additional damaging effect of continuous exposure to noise after 10 hours. The risk may be further increased if there is reduced recovery time between successive shifts.
If workers work shifts of 10 hours or more, the adjustment factor for extended shifts as set out in AS/NZS 1269.1 (see Table 3) should be added to the measured LAeq,8h before comparing it