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.