Industrial hygiene evaluation phase

The evaluation phase of industrial hygiene is the process of making measurements on some set of samples which permits a conclusion about the degrees of hazard. Before conducting an evaluation, it is necessary to make a number of choices of what and where to sample, when to sample, how long to sample, how many samples to take, what sampling and analytical methods to use, what exposure criteria to use in the analysis of the data, and how to report the results. These choices as a whole constitute the evaluation plan. The object is to find if one or more workers have an unacceptable probabiUty of being exposed in excess of some estabUshed limit. 

Industrial hygiene is a science devoted to the identification, evaluation, and control of occupational conditions that cause sickness and injury. Industrial hygienists are also responsible for selecting and using instrumentation to monitor the workplace during the identification and control phases of industrial hygiene projects. 

The three phases in any industrial hygiene project are identification, evaluation, and control ... 

Following the evaluation phase of the industrial hygiene and medical surveillance programs, one should have an excellent picture of where the problems are and a good handle on their significance. After clearly explaining the hazards to the miners, the operator needs to make available appropriate protective equipment to those employees working with exposures at or above the estabUshed lower control levels. Personal protective equipment (PPE) must be viewed as a temporary or interim step until a permanent solution to the exposure problem is implemented. 

As with evaluation, control efforts must first be targeted on the worst as determined through the three previous phases of the industrial hygiene process. In the profession of industrial hygiene, a hierarchy of controls is recognized. In order of priority, these are engineering controls, administrative controls (work practices), and as a last resort for routine or daily exposure control, use of PPE. A complete list of all controls for aU potential hazards encountered in mining is beyond the scope of this chapter however, some basic control concepts and examples of different controls follow. 

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