Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
518	INDUSTRIAL MACHINERY REPAIRERS	386
613	SUPERVISORS, EXTRACTIVE OCCUPATIONS	178
614	DRILLERS, OIL WELL	338
617	MINING OCCUPATIONS, N.E.C.	500
779	MACHINE OPERATORS, NOT SPECIFIED	338
804	TRUCK DRIVERS, HEAVY	118
848	HOIST AND WINCH OPERATORS	355
878	MACHINE FEEDERS AND OFFBEARERS	676
TOTAL		2,890

*(1) The estimates for each occupation apply across the surveyed industries in which the agent was observed. Not all industries were surveyed, and not all agents were observed in all surveyed industries. (2) When using the estimates, standard errors associated with estimates should be considered. (3) Potential exposures to a chemical agent are categorized as actual (i.e., the surveyor observed the use of the specific agent) or tradename (i.e., the surveyor observed the use of a tradename product known to contain the specific agent). The estimates presented in the table combine both categories.