Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
216	ENGINEERING TECHNICIANS, N.E.C.	153
453	JANITORS AND CLEANERS	290
534	HEATING, AIR CONDITIONING, AND REFRIGERATION MECHANICS	3,405
544	MILLWRIGHTS	711
585	PLUMBERS, PIPEFITTERS, AND STEAMFITTERS	6,388
633	SUPERVISORS, PRODUCTION OCCUPATIONS	38
653	SHEET METAL WORKERS	1,986
704	LATHE AND TURNING MACHINE OPERATORS	870
783	WELDERS AND CUTTERS	1,649
785	ASSEMBLERS	121
877	STOCK HANDLERS AND BAGGERS	77
878	MACHINE FEEDERS AND OFFBEARERS	38
TOTAL		15,727

*(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.