Hearing protection for miners in Australia

In Australia, hearing protection for miners is a major concern, particularly because of the risks associated with prolonged exposure to high noise levels that are characteristic of the mining industry. Australian regulations set a noise exposure limit of 85 dB(A) over an 8-hour period, with a rate of change of 3 dB. This means that for every 3 dB increase in noise level, the permitted exposure time is halved. In addition, the peak noise level must not exceed 140 dB(C).

Many employees in the mining sector are working longer than 8 hours. Shifts are often closer to 12 hours, meaning that the equivalent noise exposure limit would be approximately 83 dB(A)

The problem of noise in the mining sector is a serious matter requiring strong, appropriate measures. In order to combat the adverse repercussions of noise in the mining sector, there are suitable protective devices such as custom-made hearing protection. To choose the right hearing protection, you first need to be well informed about the dangers of noise exposure in the  Australian mining environment.

Sources of noise in mines

The types of noise sources in mines are extremely varied due to the various types of mines found in Australia.  Broadly speaking, mines can be categorised into surface / open pit mining and underground mining.  Within each category, there are numerous types of mines such as coal, gold, copper, uranium, and iron ore.

In Australian mines, there are several common noise sources that can contribute to high noise levels in most operational areas, both in underground and surface environments. However, providing specific noise levels is challenging because the noise levels for each type of operation can vary by as much as 10 dB, depending on various contributing factors.

Here are some of the main sources of noise in the mining industry:

Explosions and blasting

Blasting operations to fragment rock generate significant noise peaks. These explosions create intense sound waves that can affect workers' hearing, and require  a high level of protection.  Even if the noise exposure limit of 85 dB(A) over an 8-hour period (or 83 dB(A) in a 12 hours shift) is not exceeded, but there is an exposure to a peak noise level that is greater than 140 dB(C), then a minimum of a class 5 hearing protector should be worn. In such circumstances, depending upon the noise level of the explosion, double protection may be required.  If so, the minimum class of the earplug should be a class 3, worn in combination with earmuffs.

Heavy Mobile  Equipment (HME)

The use of mechanical shovels, bulldozers, transport trucks, drills and excavators generate constant and very high levels of noise. This equipment, essential for extracting and transporting materials, often operates in confined environments, amplifying its noise impact. 

The noise from HME is naturally varied and can range from about 85dB to over 100dB, depending on the type of machine and whether it’s idling or operating at maximum capacity. The class of hearing protection that is worn in the cabin can vary from class 2 to class 5, and is largely dependent upon how well the cabin is sealed. In addition, the level of communication (e.g. 2-way radio requirements) in the cabin should be taken into account.  Overprotection is ill-advised, and if a high level of communication is required, then hearing protection with uniform or flat attenuation is preferable to enable ease of communication

Crushing and grinding systems

Equipment used to crush and grind rock or ore produces high levels of vibration and noise. The noise generated by these machines can be continuous, increasing the risk of prolonged exposure to noise. It can also vary significantly, depending upon the hardness of the rock.

Ventilation and conveying systems

In underground mines, ventilation systems and conveyors (which are used to transport ore or coal) are also significant sources of noise. The continuous operation of this equipment contributes to the overall noise environment of the mine.

Pumping systems and compressors

Hydraulic and pneumatic equipment, particularly pumps and compressors, also generate noise in mining installations. Their continuous operation can contribute to workers' cumulative exposure.

Noise exposure in mines

Noise exposure in the mines is typically continuous and pervasive. Noise comes from a variety of sources, some of which are mentioned above, and  can often reach levels well above the threshold (85 dB(A)) or 83 dB(A) limit in longer shifts). For example:

• Boilermakers and shot firers can be exposed to peak noise exceeding 140 dB(C).
• In an underground coal mine, hydraulic pressure releases on the Longwall are a possible source of impulse noise exceeding 140 dB(C).

Noise levels vary according to the number of machines in use at any one time, as well as the speed of the machines. In areas of intense activity, miners can be subject to continuous exposures of around 90 to 100 dB and peaks that can exceed 140 dB during explosions. Added to this are the noises made by the miners' tools, as well as the general noise of the mine environment, such as exchanges between miners, who communicate by shouting to make themselves heard over the machines. Finally, the mining environment is conducive to sound repercussion, which is far greater in enclosed environments. These levels call for strict safety measures to protect workers' health and comply with current regulatory standards.

The consequences of noise in the Australian mining sector

The high levels of noise in Australia's mining sector have a number of negative consequences, not only for workers' health, but also for the environment and neighbouring communities. Here is a brief overview of these impacts:

Consequences for workers' health:

Hearing loss and tinnitus: Noise trauma is the second most common cause of deafness, after natural wear and tear on the hearing system. Prolonged exposure to high noise levels can lead to progressive hearing loss and tinnitus (ringing or whistling in the ears), permanently affecting employees' quality of life.

Stress and fatigue: Constant noise increases stress and fatigue and can lead to a drop in concentration, affecting not only general well-being but also work performance. Noise-induced stressgenerates psycho-social risks that can severely impact the well-being of employees.

Cardiovascular risks: Studies show that chronic exposure to a noisy environment can contribute to cardiovascular problems, notably by increasing blood pressure and the risk of heart disease.

Communication problems: Excessive noise complicates communication in the workplace, increasing the risk of errors and accidents.

Impacts on safety and performance:

Increased accidents: Poor communication due to noise, combined with reduced alertness and increased fatigue, can increase the risk of accidents and incidents on mine sites.

Reduced efficiency: Stress and fatigue induced by a high noise environment can reduce workers' efficiency and their ability to react quickly in the event of an emergency.

Indirect economic impacts

Health and compensation costs: Noise-related health problems can lead to high medical costs, sickness absence and disability compensation, impacting business productivity and profitability.

Maintenance and prevention: The need to implement preventive measures (training, personal protective equipment, machine maintenance) also represents a significant cost for operators.

In summary, noise exposure in Australian mines is a complex problem that can have major repercussions on workers' health and safety. The implementation of noise prevention and control measures is essential to mitigate these effects and ensure a safer, healthier working environment.

Effective hearing protection for noise in mines

The significant noise exposure generated by the mining industry requires the adoption of stringent hearing protection measures to protect the health of mining workers. Devices such as individual hearing protection (earmuffs, custom-moulded earplugs) and the implementation of noise management procedures (limiting exposure time, regular maintenance of equipment to reduce noise) are essential in order to minimise noise-related risks in mines.

Australian regulations impose exposure limits and require companies to implement prevention strategies to reduce the risk of hearing loss and other health problems associated with exposure to intense noise.

Custom hearing protection

Custom moulded earplugs remain unquestionably the best solution for protecting miners. Custom-made protectors fitted with acoustic filters adapted to the working environment provide ideal noise protection tailored to each type of noise -exposure. What's more, they don't isolate the user from their environment or prevent them from communicating with those around them, allowing them to hear the various warning signals. Bluetooth custom hearing protections can also be used if minors need to be connected

Manufactured using 3D technology, they are an exact match of the ear impressions (moulds) of the user. They are therefore comfortable and can be worn all day, withoutirritation. Their material ensures durability, hygiene and ease of maintenance.

Earmuffs

Earmuffs are fairly effective and can offer different levels of protection depending on the work environment. However, in the extreme climate conditions of Australian mines, they can become very uncomfortable. The high temperatures in mining sites can make wearing earmuffs unbearable, as they trap heat and increase sweating. This often leads to workers removing them, thereby exposing themselves to dangerous noise levels.

The main disadvantage of earmuffs with high protection is the total isolation they cause. Completely cut off from their external environment, the user is no longer able to communicate properly with coworkers, which can pose a real safety problem.

Disposable hearing protection

Disposable hearing protection can be used on an ad hoc basis (replacement, temporary worker, external visitor). They offer adequate protection for a short period. Generally single-use, they generate a large volume of waste if used daily (a minimum of 3 pairs per person per day is required), and their protection is often not completely effective because the user will find them difficult to insert, particularly with dirty, heavy duty gloves or dirty fingers.

QEOS: Hearing protection for miners

Cotral Lab’s QEOS hearing protection is totally adapted to the mining sector. It is easy to maintain because the material is a special resin called Crylit.  Crylit is non-porous meaning that any dirt on it is not absorbed and can be easily wiped off.  It is also waterproof and hypoallergenic. Crylit is extremely smooth, resulting in a perfect seal inside the ear canal, and it is far superior to silicone, which can become quite rough and rubbery over time.

Each Qeos hearing protector is equipped with a handle, allowing its insertion or removal without having to touch the part of the earplug that is inserted in the ear. There is also a removable cord with a clip which can attach to the miner’s clothing, ensuring that the hearing protection is always with them, and not easily lost.

If you'd like more information on the different models of Cotral Lab custom hearing protection devices, please contact us.