Workplace Sampling and Analysis

Abstract Industrial hygiene sampling is done to identify and quantify specific contaminants present in the environment, determine exposures of workers in response to complaints, assess compliance with respect to various occupational health standards, evaluate the effectiveness of engineering controls installed to minimize workers' exposures, and for other purposes. The reasons for sampling dictate to some extent the sampling strategy that should be used. Sampling can be conducted in a strategic pattern throughout an area to document the environmental characteristics of the workplace. Personal breathing zone samples can be obtained to document actual exposure conditions. The substances being evaluated determine the type of sampling devices to be used, and the analytical requirements specify time and perhaps flow rate of sampling. The occupational health standard or reference indicates whether continuous or instantaneous sampling is appropriate. In short, consideration must be given to a number of variables pertaining to the fundamental purpose of the sampling. Many analytical methods available to the industrial hygienist have become so standardized and simplified that they require relatively little experience to apply. On the other hand, many seemingly simple tests call for a basic understanding of solubility and gas laws, partial pressures, and chemical reactions. In many instances, questions arising from such considerations can be answered only by qualified specialists. The ultimate method of analysis to be used depends on the problem at hand rather than mere application of a standard method. The trend in recent years has been toward development of methods that give relatively prompt results with a high degree of accuracy. The latter aspect has increased in importance because of legal significance given to occupational health standards, particularly as promulgated under authority of the Occupational Safety and Health Act of 1970. This chapter presents a discussion of overall strategy for sampling in the workplace, statistical bases for industrial hygiene sampling, sampling techniques for gaseous and particulate contaminants, summaries of techniques available for analyzing atmospheric samples, and a discussion of biological monitoring as it relates to industrial hygiene sampling. Many of the early descriptions of industrial hygiene sampling/analysis still serve as foundations for modern, more sophisticated methods.