Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
453	JANITORS AND CLEANERS	835
518	INDUSTRIAL MACHINERY REPAIRERS	634
535	CAMERA, WATCH, AND MUSICAL INSTRUMENT REPAIRERS	3,476
549	NOT SPECIFIED MECHANICS AND REPAIRERS	4,603
768	CRUSHING AND GRINDING MACHINE OPERATORS	106
779	MACHINE OPERATORS, NOT SPECIFIED	761
783	WELDERS AND CUTTERS	3,222
TOTAL		13,637

*(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.