Noise hazards assessment

Seal, A. B. Bise, C. J. 2002. Case study using task-based, noise-exposure assessment methods to evaluate miner noise hazards. Mining Engineering, 54, 44-48. 

For example, say the potential hazard was injury and illness caused by hot work (such as, welding fumes, UV light, sparks, noise, or skin injury). The hazard assessment on an oil and gas site may identify the following requirements ... 

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. 

The hazard assessment can confuse some employers. What is needed is to evaluate prior OSHA 200 logs and injury reports, minutes of safety meetings, and any air or noise surveys. This should be followed by a thorough walk-through of the warehouse to look for ... 

A circumstance worth mentioning at this point is the response appropriate to deal with nuisance and esthetic issues such as odor or noise when no hazard can be identified. A risk classification of "insignificant," with respect to health or the environment, would likely be selected and no response justified in the case of a disposal site evaluation where only odor is the problem. In these instances, appropriate responses should be developed using a process which reflects the economic, social and political impacts of the problem rather than the assessment process being described which has been developed to deal with hazards to health. 

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. 

Human loudness perception depends in a complex manner on both frequency and the overall loudness of sound. (For example, bass is more difficult to hear in music played at low volume than in the same music played at high volume.) To capture this behavior, two weighting scales have been developed for use in sound hazard analysis. The most common of these is the A weighting scale, which is commonly used to assess occupational and environmental noise. The A scale weights sounds in the 1000-6000 Hz range much more heavily than low-frequency sounds. The A-weighted intensities (dBA) of some common sounds are listed in Table 5. By contrast, the C weighting scale is used for very loud sounds and is a much flatter function of frequency. 

Assessing hazardous noise conditions in the workplace involve the following ... 

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. 

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. 

When dealing with hazards of environments, there are additional important factors. Environments include such things as heat, light, noise, vibration, pressure, chemicals, and radiation (non-ionizing and ionizing). Designers must know what level of exposure exists or could exist. One must consider the exposure s effects on people. There is a need to know how exposures occur. There is a need to detect and measure the exposures. People cannot observe many environmental hazards or assess them accurately on their own. 

The basic work of providing a comprehensive assessment (Chapter 10) was done by a committee composed of the safety director, the nurse practitioner, the director of manufacturing, the supervisor of maintenance, and two production employees, one from the day shift and one from the evening shift. In addition, consultation was requested from the loss control department of their insurance carrier. The loss control engineer was an industrial hygienist who confirmed the need to monitor for noise in the manufacturing area. She also helped the nurse practitioner and the human resources director write job descriptions for all major employee classifications. The descriptions emphasized important safety considerations— for example, the amount of weight lifted and the hazardous substances handled. 

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. 

Arc welding has been widely introduced to replace riveting and subsequently noise levels have been reduced. Again such alterations may introduce new hazards (e.g. welding fumes) and the risks from these must be similarly assessed with the implementation of adequate controls. 

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. 

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

Ideally, qualitative and quantitative information is required for each hazard present. For example, the sound level and frequency response of a source of noise needs to be assessed before the correct earmuffs or earplugs can be selected, whilst suitable gloves to protect against the degreasing action of a solvent cannot be chosen unless the chemical... 

It is possible to effectively determine risk wherever there is a possibility to unequivocally and quantitatively assess the risk parameters, that is, the probability and consequence of a negative event this includes technologies that archive detailed data on individual injuries, accidents, faults, and assess risks (hazards) that can be quantified by explicit values, for example, noise, vibration, dustiness, chemical substances content, and so on. In case of technical risks, it is possible on some occasions to define consequences by means of financial units, although this procedure is applicable only in case of incidents covered by insurance. 

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