A recent preliminary noise assessment of a car washing and detailing centre lead to consideration of Hand Arm Vibration (HAV). Car washing centres may be perceived as being workplaces that may have high noise levels. This can be the case, depending on the type of equipment that is used. The main sources of noise may be from pressure washing and rotating brushes and equipment as well as the vacuums to clean the car prior to detailing.
Where was Hand Arm Vibration Observed
In this case study, the noise levels were found to predominantly be from the high pressure washers when cleaning the exterior of the car and the engine bay. In these cases many employees simply read the regulations and are of the understanding that the noise level should be below 85 dB(A). However further observations need to be taken to assess confounding factors that may increase the risk of Noise Induced hearing Loss (NIHL).
One of the confounding factors involved in NIHL and Industrial Deafness is that of Hand Arm Vibration. The effect of Hand Arm Vibration causes a sympathetic reflex of the ear which has an effect on the perceived noise levels. What should be considered at 85 dBA should now be that of 80 dB(A) if there is significant Hand Arm Vibration. The noise assessment should be assessed differently now due to the Hand Arm Vibration. The way in which the noise levels are to be assessed is further outlined within the WorkSafe Australia Model Code of Practice “Managing Noise and Preventing Hearing Loss at Work”
Measuring Hand Arm Vibration and Noise
The Safe Environments team can undertake noise assessments to AS 1269.1 using both sound level meters and personal dosimeters. If Hand Arm Vibration is observed, then this can affect the exposure standard when conducting a noise assessment. In these instances Safe Environments can undertake Hand Arm Vibration testing to AS ISO 5349.1-2013 Mechanical vibration – Measurement and evaluation of human exposure to hand-transmitted vibration – General requirements.
Safe Work Australia Code of Practice – Hand Arm Vibration
The Safe Work Australia Code of Practice indicates that the workplace noise levels should be reduced to below 80 dB(A) where the is Hand Arm Vibration greater than 50% of the vibration exposure level. The exposure standard for Hand Arm Vibration is 2.5 m/s2 as an action level. These measurements for HAV can be undertaken by Safe Environments, using top of line equipment, the Bruel and Kjaer Type 4447 vibration analyser.
Control Measures for Hand Arm Vibration
In this case study the short term intervention strategy is to use anti-vibration gloves to reduce the effect of the Hand Arm Vibration. Other methods to reduce overall exposure is the rotation of employees from not just washing using pressure washers, but to undertake detailing work by hand. The hand detailing work does not expose workers to the same levels of noise and vibration.
For further assessments on Hand Arm Vibration, Whole Body Vibration, Audiometric and Noise Testing, please contact the occupational Hygienists at Safe Environments, based in Sydney and Melbourne.