Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
073	CHEMISTS, EXCEPT BIOCHEMISTS	103	8
453	JANITORS AND CLEANERS	142
518	INDUSTRIAL MACHINERY REPAIRERS	159
519	MACHINERY MAINTENANCE OCCUPATIONS	212
544	MILLWRIGHTS	3,917	84
563	BRICKMASONS AND STONEMASONS	185
575	ELECTRICIANS	174
585	PLUMBERS, PIPEFITTERS, AND STEAMFITTERS	145
724	HEAT TREATING EQUIPMENT OPERATORS	247
756	MIXING AND BLENDING MACHINE OPERATORS	338
766	FURNACE, KILN, AND OVEN OPERATORS, EXC. FOOD	1,814	253
777	MISCELLANEOUS MACHINE OPERATORS, N.E.C.	2,017	97
779	MACHINE OPERATORS, NOT SPECIFIED	130
849	CRANE AND TOWER OPERATORS	516
859	MISCELLANEOUS MATERIAL MOVING EQUIPMENT OPERATORS	1,487	41
865	HELPERS, CONSTRUCTION TRADES	288
883	FREIGHT, STOCK, AND MATERIAL MOVERS, HAND, N.E.C.	253
889	LABORERS, EXCEPT CONSTRUCTION	465
TOTAL		12,593	484

*(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.