Hand-arm vibration (HAV)

Studies have indicated that there is a link between exposure to hand-arm vibration and hearing loss. Workers who use equipment such as chainsaws that subject the worker to both hand-arm vibrations and to noise may be more likely to suffer from hearing loss. Tools that may expose workers to both noise and hand-arm vibration include:

  • pneumatic and electrical rotary tools such as concrete breakers, grinders, sanders and drills percussive tools such as chippers and riveters, and
  • petrol-powered tools such as lawn-mowers, brush-cutters and chainsaws.

Control measures to reduce exposure to hand-arm vibration may involve finding alternative ways to do the work that eliminates the need to use vibrating equipment or to purchase tools that produce less vibration.

Whole-body vibration (WBV)

Whole-body vibration (WBV) is vibration transmitted to the whole body by the surface supporting it, for example through a seat or the floor. It is commonly experienced by drivers, operators and passengers in mobile plant when travelling over uneven surfaces. WBV may also be experienced while standing, for example standing on platforms attached to concrete crushing plant. WBV includes sharp impacts like shocks and jolts. Exposure to WBV mainly occurs in vehicles used off-road or on unsealed roads, for example on farms and construction, mine and quarry sites. It can also occur in other places like in small, fast boats and in helicopters.

There is evidence workers who use vibrating plant and are exposed to noise at the same time are more likely to suffer hearing loss than workers exposed to the same level of noise alone. Exposure to both vibration and noise is also understood to increase musculoskeletal problems.

Measures to eliminate or minimise exposure to WBV should be considered (in the following order):

  • at the source of vibration
  • along the paths of the vibration, and
  • at the position where the vibration enters the worker.

Consider if hazards from using vibrating plant can be completely removed from the workplace, for example by introducing remotely controlled mobile plant rather than plant driven by workers.

Ototoxic substances

Exposure to some chemicals can result in hearing loss. These chemicals are known as ototoxic substances. Hearing loss is more likely to occur if a worker is exposed to both noise and ototoxic substances than if exposure is just to noise or ototoxic substances alone.

There are three major classes of ototoxic substances:

  • solvents
  • heavy metals
  • asphyxiants.

Exposure standards for chemicals and noise do not take account the increased risk to hearing caused by ototoxic substances. Until revised standards are established, it is recommended that the daily noise exposure of workers (on an eight-hour shift) exposed to any of the substances listed in Table A1 be reduced to 80 dB(A) or below. They should also undergo audiometric testing and be given information on ototoxic substances.

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