The practice of industrial hygiene

As we discussed earlier, the tenets of industrial hygiene are the recognition, evaluation, and control of workplace health hazards. The goal of the IH is to provide a safe and healthful work environment for all workers. 

IHs categorize occupational health hazards into four categories, referred to as environmental stressors chemical, physical, biological, and ergonomic. 

Chemical stressors include substances such as solvents, acids, caustics, and alcohols. 

Physical stressors include ionizing radiation (alpha, beta, gamma, neutron, X-ray radiation), nonionizing radiation (infrared, ultraviolet, visible light, radio frequency, microwave, and laser radiation), 

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The air inside a factory building can be polluted by release of contaminants from industrial processes to the air of the workroom. This is a major cause of occupational disease. Prevention and control of such contamination are part of the practice of industrial hygiene. To prevent exposure of workers to such contamination, industrial hygienists use industrial ventilation systems that remove the contaminated air from the workroom and discharge it, either with or without treatment to remove the contaminants, to the ambient air outside the factory building. 

In 1970 the US Congress enacted a health and safety law that continues to have a significant impact on the practices of industrial hygiene in the chemical industry the Occupational Safety and Health Act of 1970 (OSHAct). To appreciate the significance of the OSHAct, it is helpful to review regulations and practices2 before 1970. 

The introduction to the ACGIH TLV list explains that TLVs are intended for use in the practice of industrial hygiene, they do not represent fine lines between safe and dangerous concentrations of hazardous chemicals. However, the origiiiators of the list were confident that TLVs would protect the majority of workers firm haxm and they have been finis extensively promulgated as, essentially safe levels... 

These limits are intended for use in the practice of industrial hygiene as guidelines or recommendations in the control of potential health hazards and for no other use, e.g., in the evaluation or control of community air pollution nuisances in estimating the toxic potential of continuous, uninterrupted exposures or other extended work periods as proof or disproof of an existing disease or physical condition or adoption by countries whose working conditions differ from those in the United States of America and where substances and processes differ. These limits are not fine lines between safe and dangerous concentration nor are they a relative index of toxicity. They should not be used by anyone untrained in the discipiine industrial hygiene. 

Reference values intended as guidelines for the evaluation of potential health hazards in the practice of industrial hygiene. BEIs represent the levels of determinants that are most likely to be observed in specimens obtained from a healthy individual who has been exposed to chemicals to the same extent as an individual with inhalation exposure to the Threshold Limit Value (TLV ). TLVs and BEIs are registered terms of the American Conference of Governmental Industrial Hygienists (ACGIH ). See also Threshold Limit Values (TLVs ). 

ACGIH publishes BEIs as reference values. They intend to help with evaluation of potential health hazards in the practice of industrial hygiene. BEIs apply to 8-hr exposures, five days a week. Individual differences may account for occasional measurements above BEIs. If a sample exceeds a BEI consistently, there is cause for investigation of the workplace. BEIs should have a backup method for assessing exposures. They are not the primary means for determining if a hazard exists. 

Introduction to Industrial Hygiene / 115 Figure 6-5. The practice of industrial hygiene. 

Certified Industrial Hygienist (CIH) means one certified in the practice of industrial hygiene by the American Board of Industrial Hygiene. 

The practice of industrial hygiene or environmental health is based on the concept that for each substance there is a safe or tolerable lower level of exposure below which significant injury, illness or discomfort will not occur. The industrial hygienist protects the health of the worker by determining this safe limit of exposure for a substance and then controlling the environmental conditions so that exposure does not exceed that limit. 

Analytical chemistry is important in practically all areas of human endeavor and in all spheres of the environment. Industrial raw materials and products processed in the anthrosphere are assayed by chemical analysis, and analytical monitoring is employed to monitor and control industrial processes. Hardness, alkalinity, and trace-level pollutants (see Chapters 3-5) are measured in water by chemical analysis. Nitrogen oxides, sulfur oxides, oxidants, and organic pollutants (see Chapters 6-8) are determined in air by chemical analysis. In the geosphere (see Chapters 9-11), fertilizer constituents in soil and commercially valuable minerals in ores are measured by chemical analysis. In the biosphere, xenobiotic materials and their metabolites (see Chapters 2 and 12) are monitored by chemical analysis. As discussed further in this chapter, analytical chemistry is very important in the area of occupational health and the practice of industrial hygiene. 

A not-for-profit corporation organized to improve the practice and educational standards of the profession of industrial hygiene. 

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. 

Toxicity Data on Af- Vinyl-2-Pyrrolidinone. Results of a chronic inhalation study in rats warrant a review of industrial hygiene practices to assure that VP vapor concentrations are maintained at a safe level. One of the manufacturers, ISP, recommends that an appropriate workplace exposure limit be set at 0.1 ppm (vapor) (9). Additionally, normal hygienic practices and precautions are recommended, such as prompt removal from skin and avoidance of ingestion. In case of accidental eye contact, immediately flush with water for at least 15 minutes and seek medical attention. Refer to the manufacturers Material Safety Data Sheets for more detailed information. Table 3 provides some toxicity data. 

Cralley L.J., Cralley L.V. (eds) Patty s Industrial Hygiene and Toxicology. Volume III Theory and Rationale of Industrial Hygiene Practice. 2nd ed., 3A The Work Environment. Wiley, New York (1985)... 

Ongoing training should consist of regularly scheduled drills and safety meetings in conjunction with supervisory reviews of industrial hygiene, materials handling, and emergency practices. In this manner, the procedures in effect always correspond to the chemicals and equipment in use. 

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