2. Understanding noise hazards and risks
There are activities undertaken in schools that may expose staff to elevated levels of noise that could pose a risk to hearing loss. This risk of hearing loss increases depending on the level of noise and length of exposure time.
There are 2 types of noise which staff may be exposed to:
- Annoyance noise may interfere with communication or pose distraction. Annoyance noise may need to be assessed and controlled to avoid negatively effecting staff concentration and wellbeing. Annoyance noise is unlikely to pose serious risk of noise induced hearing loss.
- Excessive noise is noise that exceeds those levels defined by Compliance code: Noise – WorkSafe and could pose a risk to hearing loss. This risk may increase depending on the level and length of time of exposure to the excessive noise.
This procedure focuses on identifying, assessing and addressing excessive noise hazards and risks.
Exposure to excessive noise (either a single very loud noise or by repeated exposure to various loud noises over a period of time) can cause damage to the inner ear, causing hearing loss. Once damage occurs it cannot be repaired, however, it can be prevented.
The exposure standard states that occupational noise must not exceed 85 decibels (dB) averaged (A) over an 8-hour period or a maximum (peak) noise level of 140 dB. Noise levels above these are hazardous and are deemed unsafe.
Exposure level dB* | Maximum exposure time to ensure that 85 dB(A) is not exceeded | Example of exposure level |
---|---|---|
50 | Unlimited unprotected exposure | Quiet office |
60 | Unlimited unprotected exposure | Normal conversation |
70 | Unlimited unprotected exposure | Vacuum cleaner |
80 | Unlimited unprotected exposure | Heavy traffic |
85 | 8 hours | No example provided |
88 | 4 hours | No example provided |
91 | 2 hours | Welder/lawnmower |
94 | 1 hour | Motorcycle |
97 | 30 minutes | Sander |
100 | 15 minutes | Handheld drill Large crowd at sporting event |
103 | 7.5 minutes | No example provided |
106 | 3.8 minutes | No example provided |
109 | 1.9 minutes | Chain saw Shouting or barking in the ear |
112 | 57 seconds | No example provided |
115 | 28.5 seconds | No example provided |
118 | 14.3 seconds | No example provided |
121 | 7.1 seconds | Standing beside or near sirens |
124 | 3.6 seconds | No example provided |
127 | 1.8 seconds | No example provided |
130 | 0.9 seconds | Live concert |
140 | No safe unprotected exposure | Firecrackers |
150 | No safe unprotected exposure | No example provided |
160 | No safe unprotected exposure | Explosives |
*Decibels (dB) are measured in a logarithmic scale. Exposure recommendations to noise over 80 dB significantly decrease even though the level of dB only go up incrementally.
Reviewed 15 January 2023