Noise personal hearing protection

Many stone processing operations produce high sound levels. Operators exposure to noise is controlled by a combination of reducing/containing it at source, excluding it from control rooms, and the use of remote cameras with monitors in control rooms. Effective personal hearing protection is still required when operators are required to enter noisy areas. 

Noise is often a problem, so the workplace and machinery must be designed to reduce noise exposure (see Chapter 1). Where appropriate, personal hearing protection must be provided and worn. 

Ear-plugs are only generally effective up to noise levels of 100-105dBA while ear-muffs can provide protection at higher noise levels to meet a 90 dBA criterion, for noise received by the wearer. Comparative attenuation characteristics for various personal hearing protection devices are shown in Figure 20.15. 

If it is not reasonably practicable to reduce noise exposure levels to below 90dB(A) LEP,d then the employer is required to provide personal hearing protection (Reg. 8). An alternative to personal protection is the provision of hearing havens from which the worker can carry out his duties. Areas where there remains a hearing risk shall be designated ear protection zones and be identified as such (Reg. 9). 

Common controls. Noise can be controlled in the work environment by isolation or enclosure of the source of the noise. Control rooms can be constructed in treatment plants to provide a low-noise environment for operators. If operators must enter high-noise areas they can be required to use personal hearing protection to protect against high noise levels. 

The noise levels in most laboratories are usually not excessive, but there are laboratory facilities in which noise can reach levels forwhich hearing protection should be provided or the employees required to be involved in a hearing conservation program. It would be preferable, of course, if the noise levels could be lowered rather than to depend upon personal protective devices. 

New regulations introduced in 2006 reduce the first action level to 80dB(A) and the second level to 85dB(A) with a peak action level of 98dB(A) or 140 Pa of pressure. Every employer must make a noise assessment and provide workers with information about the risks to hearing if the noise level approaches the first action level. They must do all that is reasonably practicable to control the noise exposure of their employees and clearly mark ear protection zones. Employees must wear personal ear protection while in such a zone. 

If other means of controls prove to be impossible or infeasible, the use of personal protective equipment by employees may become necessary. Such control methods, however, do not reduce or eliminate the source of the potential hazard and are the least preferred choice for controlling exposure. Personal protective equipment includes air-purifying and air-supplying respirators, hearing protection to reduce noise exposures, eye and face protection and gloves, boots and other impervious clothing. 

Previous evaluations of noise exposure and audiometric tests made by the technical services of the company, resulted in the selection of two models of hearing protection for personal protection the 3M1271 and the SMARTFIT. 

In a general note it is stated that there is no workplace, and therefore no workers, with the Lcpeak parameter close to lower action value, whereby the achieved values refer to LAeq parameter (in the case of workplaces) or LEX, 8H parameter (for workers). Table 4 summarizes the results obtained for the noise levels per workplace for each industrial sector, based on the amounts stipulated legally. In 55% of the workplaces, the noise levels determinates that the workers should use appropriate personal protective equipment, being mandatory the use of hearing protection in 31 /o of workplaces in the Portuguese industry. 

However, it is important to note that noise levels above 80 dB require taking action measures according to the NR-6, which states that the worker should use personal protective equipment (PPE), i.e. a hearing protection (Brasil 1978b). The basketball teacher reported that the height of the... 

PPE (personal protective equipment) subteam This team can ensure that PPE requirements are defined for the different tasks within the plant and then conduct audits for compliance. When new equipment or processes are brought into the plant, they can assess the PPE required. Noise abatement subteam Annual noise level audits, annual hearing testing, and defining the need for sound enclosures would fall within the scope of this team. 

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