Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
216	ENGINEERING TECHNICIANS, N.E.C.	7
224	CHEMICAL TECHNICIANS	1,445	230
453	JANITORS AND CLEANERS	2,409
507	BUS, TRUCK, AND STATIONARY ENGINE MECHANICS	682
516	HEAVY EQUIPMENT MECHANICS	30
518	INDUSTRIAL MACHINERY REPAIRERS	901
549	NOT SPECIFIED MECHANICS AND REPAIRERS	1,401
585	PLUMBERS, PIPEFITTERS, AND STEAMFITTERS	135
637	MACHINISTS	185
684	MISCELLANEOUS PRECISION WORKERS, N.E.C.	620
756	MIXING AND BLENDING MACHINE OPERATORS	58
783	WELDERS AND CUTTERS	3,905	5
785	ASSEMBLERS	2,819	602
889	LABORERS, EXCEPT CONSTRUCTION	262
TOTAL		14,859	837

*(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.