Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
453	JANITORS AND CLEANERS	2,549
507	BUS, TRUCK, AND STATIONARY ENGINE MECHANICS	454
514	AUTOMOBILE BODY AND RELATED REPAIRERS	582
516	HEAVY EQUIPMENT MECHANICS	186
519	MACHINERY MAINTENANCE OCCUPATIONS	703
534	HEATING, AIR CONDITIONING, AND REFRIGERATION MECHANICS	12
549	NOT SPECIFIED MECHANICS AND REPAIRERS	480	17
585	PLUMBERS, PIPEFITTERS, AND STEAMFITTERS	14
736	TYPESETTERS AND COMPOSITORS	999
777	MISCELLANEOUS MACHINE OPERATORS, N.E.C.	24
783	WELDERS AND CUTTERS	4,914
785	ASSEMBLERS	211	27
853	EXCAVATING AND LOADING MACHINE OPERATORS	781
855	GRADER, DOZER, AND SCRAPER OPERATORS	468
TOTAL		12,378	44

*(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.