Finger pain, numbness and even gangrene are the symptoms of a serious occupational disease that strikes up to 50 per cent of hand tool users. The cause is vibration but while the impacts are well-known internationally, WA Safety Show exhibitor Noise and Vibration Measurement Systems describes its effect as a "sleeping giant" in Australian workplaces.
Ahead of the show, which will run from August 24 to 26, Noise and Vibration Measurement Systems' Stewart Wood says hand tools such as grinders could damage the health of Australia's manufacturing workers irreversibly.
"Almost everyone understands the need to protect their hearing in noisy workplaces but it comes as a shock to most employers that vibration is just as hazardous," he says.
According to the University of Tennessee Institute for the Study of Human Vibration, 8 to 10 million workers in the United States alone are exposed to occupational vibration every day.
While the symptoms of HAV Syndrome are clear, measurement is more complex. The International Standards, ISO 2631 and ISO 5349, that define how vibration exposure is assessed stipulate that the three axes – x, y, and z – must be taken into account because the human body reacts differently to horizontal and vertical vibration.
Apart from direction, the other three characteristics of vibration must be measured: magnitude, frequency and duration. Western Australia's SafetyLine Institute last year issued a human vibration guide detailing each of the characteristics.
Magnitude represents the acceleration of the oscillating objects and is expressed as a root-mean-square (r.m.s.) value in units of metres per second squared (m/s²). Unlike other hazards, frequency refers not to the occurrence of vibration but to the motion itself. Because each part of the human body has its own natural frequency, different vibration frequencies have differing impacts across the body.
The SafetyLine guide and ISO standards include complex algorithms for the calculation of exposure and Noise and Vibration Measurement Systems runs one-day courses for workplaces keen to control the risk of vibration-related injuries and recommends participants have basic engineering mathematics. In good news for workplaces seeking a simpler solution to vibration exposure monitoring, Noise and Vibration Measurement Systems does offer pocket analysers. Stewart Wood says the Human Vibration Analyzer Type 4447 is typically used to sample the vibration workers are exposed to during different tasks.
Noise and Vibration Measurement Systems will have vibration analysers and noise dosimeters at the WA Safety Show, which runs from August 24 to 26 at the Perth Convention Exhibition Centre. It is run by Australian Exhibitions & Conferences .