Noise risk assessment

Table 17.7 gives other information on simple tests to determine the need for a noise risk assessment. 

Observation at the workplace Likely noise level A noise risk assessment must be made if this noise level persists for ... 

This text is a comprehensive collection of concise and readable explanations of basic principles in toxicology and the potential hazards of chemicals. It contains more than 1000 entries, including entries related to research and clinical toxicology, risk assessment, ecotoxicology, epidemiology, radiation, noise, information resources, organizations, and education. As with the 1st edition, this volume is extensively cross-referenced, contains a detailed index, and provides numerous references to primary and secondary literature. 

As a supplement to R2.2.1766-03, specific recommendations are planned on methods and criteria assessment (scales, models, etc) of workers health (morbidity, mortality, etc), workplace factors (noise, vibration, dust, chemicals, etc), work load (physical load nervous tension), and reproductive health risk assessment. Relevant data have been published in handbook on occupational risk (Izmerov Denisov, 2003). 

The identification of working context and hazard typology to analyze (ordinary or specific hazards such as noise, vibration, and so on) usually establishes what risk assessment techniques should be used as similar techniques may not necessarily yield the same results. 

Life-cycle assessment when carried ont according to the ISO rules has shown its ability to deliver data for certain more global environmental compartments like the impact potential on saving of resonrces, global warming potential, acidification, ozone depletion, and the like. It nsnally does not cover local effects such as noise or smell and hazardons snbstances. Here risk assessment or other methodologies are needed. The evalnation of effects regarding human toxicity is hampered by a lack of sufficient data and by a still undecided question of data evaluation. Thns, life-cycle analysis is a nseful tool but not the only answer to all enviromnental aspects. 

Controlled risk assessment (4) Barriers adequate, isolation by distance acceptable, and insulated control panels further reduce risk of exposure to hazardous noise levels. A controlled RAC of 3E is assigned because, even if a relief did occur, the distance and isolation would create a marginal, rather than critical, risk. 

The Regulations place a duty on employers to carry out noise assessments (Reg. 4) where there is a risk of hearing damage, and to maintain records of each assessment (Reg. 5). Where there is an identified noise risk there is a requirement to reduce the emission to the lowest reasonably practicable level (Regs. 6 and 7). 

Safety professionals must understand that risk assessment is as much an art as science and that subjective judgments—educated, to be sure— are made on incident or exposure probability and the severity of outcome to arrive at a risk category. Also, it must be recognized that economically applicable risk assessment methodologies have not been developed to resolve all risk situations. As an example, this author was asked How would you assess the cumulative risk in an operation in which there was an unacceptable noise level and toluene was used in the process It was hoped that a search into resource material, such as EPA s (2003) Framework for Cumulative Risk Assessment would provide an answer. That inquiry was not successful. EPA is cautionary about cumulative risk assessment methods. Their report says ... 

Where multiple, diverse hazards exist, the practical approach is to treat each hazard independently, with the intent of achieving acceptable risk levels for all. In the noise and toluene example, the hazards are indeed independent. In complex situations, or when competing solutions to complex systems must be evaluated, the assistance of specialists with knowledge of more sophisticated risk assessment methodologies such as Hazard and Operability Analysis (HAZOP) or Fault Tree Analysis (FTA) may be required. However, for most applications, this author does not recommend that diverse risks be summed through what could be a questionable methodology. 

The risk assessment should be reviewed if circumstances in the workplace change and affect noise exposures. Also it should be reviewed regularly to make sure that the employer continues to do all that is reasonably practicable to control the noise risks. Even if it appears that nothing has changed, employers should not leave it for more than about two years without checking whether a review is needed. 

The risk assessment will have produced information on the risks and an action plan for controlling noise. Employers should use this information to ... 

The hazards need to be identified and the risks assessed for example, in fhe case of air contaminants the nature of the substance(s) present and the estimated exposure concentration, or, with noise, measurement of sound levels and frequency characteristics. 

Where employees are likely to be exposed to noise levels at or above the lower exposure action value, the employer must ensure that a noise survey is carried out by a competent person (reg. 4). Records of this assessment must be kept (reg. 5). In some cases the level of noise to which an employee is exposed varies considerably over the duration of a shift making it difficult to assess the exposme from a single or a few spot measurements. The use of a dosimeter will enable a single figure to be derived for a shift. The dosimeter is worn with the microphone close to the ear for the period of the shift and the results either read directly from the instrument or downloaded to a computer. When using the dosimeter it is important that the wearer works to his or her normal pattern and does not spend longer than normal periods in a noisy environment. Where a noise risk has been identified there is a requirement on the employer to reduce the emission to the lowest reasonably practicable level (reg. 6). 

There is (Annex A) a very comprehensive risk assessment list (aid memoir) covering such headings as radiation, noise, thermal hazards, vibration, etc. 

American Industrial Hygiene Association (AHA) http //www.aiha.org/Pages/default.aspx (accessed October 14, 2010). Serving the needs of occupational and environmental health professionals practicing industrial hygiene, AHA s more than 30 technical committees deal with such concerns as exposure and risk assessment strategies, indoor environmental quality, workplace environmental exposure levels, noise hazards, and respiratory protection. Special events or services AHce annual conference, co-sponsored by AHA and ACGIH. Web site offers an electronic discussion list. 

Table 5 summarizes the results obtained for the workers exposure to noise in each industry in accordance with what is legally stipulated. Based on the analysis of the results it can be concluded that 63 /o of the workers should use ear protectors, being mandatory the use of this protection equipment to 33%. Companies should conduct risk assessment, the adoption of measures to prevent or control the risk, perform appropriate control measures and monitoring the health of their workers in order to prevent workers being not harmed by activities with excessive noise levels. 

Risk assessment is the basis of the Regulations which came into operation on 1 January 1993. However, this duty is not new. Health risk assessments are required under the COSHH Regulations 1988 and hearing risk assessments under the Noise at Work Regulations 1989. The duties under the 1992 six jCm pack legislation are outlined below. 

Specific legislation on noise in all places of work, including construction, is contained in the Noise at Work Regulations 1989. The Personal Protective Equipment at Work Regulations 1992 require PPE to be selected according to criteria established in the risk assessment. Equipment provided must conform to EC standards. 

Identify hazards and risk levels at pre-construction phase to decide on necessary control measures, then include details of controls in pre-tender safety plan. Construction phase safety plan should contain full details of measures to be taken and checked on regularly. Written risk assessments must be available. Planning permission may impose conditions such as noise and working hours restrictions, also delivery hours. Environmental section of safety plan must be reviewed for completeness. Access and security arrangements including fencing need attention at an early stage. 

V rokannas, H., H. Anttonen, and J. Niskanen. Health Risk Assessment of Noise, Hand-Arm "Vibration and Cold in Railway Track Maintenance. International Journal of Industrial Ergonomics 13, no. 3 (1994) 247-252. 

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