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1. Developing a ‘hierarchy of control’ approach to managing our occupational health exposures
Across our Company, there are a variety of site-based exposures that have the potential to cause long-term health effects. The most appropriate approach to these risks is to reduce exposure to the individual. Personal protective equipment (PPE) has been a customary form of protecting employees from adverse exposures. However, in applying a ‘hierarchy of control’, our goal is to reduce the potential exposures in an absolute sense.
The ‘hierarchy of control’ approach involves methods to decrease the exposure source itself or to minimise the potential amount of employee contact. At the highest level, this involves removal of the exposure or substitution of the exposure to one with less or no harmful effects. Where the exposure source cannot be removed, there may be direct engineering solutions that can be employed to significantly reduce the exposure. This is particularly the case in responding to the problem of noise generated from machinery, which is a focus at a number of our operations.
PPE sits at the lower end of the ‘hierarchy of control’. However, it is still a very important element in the efforts of mining and smelting industries to ensure the health of employees is not adversely affected. It is important that PPE programs are well managed. This includes selection of appropriate equipment for the exposure, adequate training of employees in use of the equipment, high standards of maintenance, and a system for ensuring compliance in the use of the equipment by all employees.
The target for our operations is to reduce exposures over time through a ‘hierarchy of control’ approach. A long-term aim would be to create a work environment where PPE is not required. However, in the interim, correct use of PPE remains critical to ensuring the health of our employees while programs to reduce exposure are implemented.
Noise is a significant exposure for employees in the mining and minerals processing industry. The application of engineering processes, particularly through the use of barrier and insulation techniques, may reduce exposure to a point where no hearing protection is required by employees. Our Iron Ore operation at Port Hedland, Australia, has recently installed fibreglass insulation in the crusher plant, which has significantly reduced noise levels in this area. They have also fully enclosed the blower units in the beneficiation plant, which has reduced the level of noise to below the exposure limit. The progress in noise reduction at the site is reinforced by a ‘buy quiet’ policy that has been developed through Engineering Services.
Noise and dust are constant sources of adverse exposure for those in underground mining in the coal industry. At our Khutala coal mine in South Africa, specific attention has been given to engineering underground mining machinery to enclose the cabins of operators. This has markedly reduced the noise and dust exposure. Another exposure for underground coal miners is that of diesel particulates. Our Illawarra Coal operation in Australia has been sponsoring a study of this exposure over many years, and a high-quality filter mechanism to reduce diesel particulate exposure in this group has now been developed.
Another good example of where we are employing the ‘hierarchy of control’ approach to reduce employee exposure is at our copper oxide plant in Tintaya, Peru. By applying world's best engineering processes, emissions of sulphuric acid from the system have been significantly reduced. Although emissions are now well below current exposure standards, employees still wear PPE as added protection to ensure minimum adverse effects.
In the aluminium industry, it has long been known that the smelting process can induce asthma in employees. Older forms of this smelting process are more prone to emissions that may produce asthma. At our Bayside aluminium smelter operation in South Africa, where these processes are used, guards and extraction units have been installed to significantly reduce exposure for employees.
As with many other areas of health management, occupational health requires a strong focus on prevention and therefore reduction of harmful exposures. A preventive approach to managing our health issues will focus our attention towards the concept and design phase of new operations, to ensure potential health exposures have been minimised as much as possible. Our targets reflect this as we seek to achieve a year-on-year reduction in the number of our employees who would be exposed above occupational exposure limits, if not for the protective effect of PPE.
