Two methods for establishing industrial hygiene priorities.

There is a need for a method to establish industrial hygiene priorities so that our limited health resources can be directed to those chemicals and conditions of use that pose the greatest risk to employee health. The Health Team hazard rating method presented in this paper accomplishes this goal and has been used successfully for several years. Also presented is a proposed method for calculating hazard ratings for inhalation exposures to gases and vapors that may allow those responsible for promulgating standards to address the hazard rather than the toxicity of a regulated chemical.

Computer handling of occupational exposure data.

A system has been developed for the computer handling of industrial hygiene data in the Michigan Division of Dow Chemical U.S.A. With the implementation of this system, future epidemiological studies might be completed in a few weeks as opposed to months when done menually. The system is capable of providing lists, either current or historical, of the chemicals used in a particular building; and all the available exposure data for specific employees can be obtained throughout their entire periods of employment. The system is also capable of summarizing all available exposure information for a given chemical. The heart of the chemical exposure data system lies in the record content. Each record contains: 1. Chemical identification number; 2. Employee number; 3. Job classification number; 4. Department index number; 5. Data type code; 6. Exposure data; 7. Units code; 8. Date; 9. Building number and 10. Reference. A detailed discussion of each of these parameters is contained in the text.

Computerization of data from continuous and sequential air monitoring systems.

Continuous and sequential area air monitoring systems are more frequently becoming a necessity in both new and existing chemical manufacturing and processing plants. While these systems have most frequently been installed to alert employees to conditions of possible acute overexposure, they generate a wealth of data valuable in documenting employee exposures over extended period of time. Within the Dow Chemical Company, use of a dedicated microcomputer with area air monitoring systems has proven helful in summarizing each days' data and in calculating month-to-date totals for use in employee exposure documentation over long time periods.

Local exhaust ventilation principles.

Many industrial local exhaust ventilation systems have inadequate performance. This occurs because systems were poorly designed. Frequently, the performance of the local exhaust ventilation systems is impaired because of modifications. Nine factors which should be considered when designing a local exhaust ventilation system include: 1. minimizing capture distance; 2. providing adequate capture velocity (or adequate exhaust rate); 3. using gravitational force; 4. providing adequate conveying velocity for particulates; 5. minimizing pressure drop; 6. incorporating "containment" whenever possible; 7. providing even airflow distribution at hood faces; 8. placing the fan as the last system element whenever possible; and 9. installing a static pressure gauge and testing the system.