SIC	Industry Description (1972)	Total # Employees (Male & Female)	Total # Female Employees
13	OIL AND GAS EXTRACTION	1,199
16	HEAVY CONSTRUCTION CONTRACTORS	3,129	75
17	SPECIAL TRADE CONTRACTORS	6,424
20	FOOD AND KINDRED PRODUCTS	294
28	CHEMICALS AND ALLIED PRODUCTS	4,051	2,102
32	STONE, CLAY, AND GLASS PRODUCTS	1,019
34	FABRICATED METAL PRODUCTS	3,100
35	MACHINERY, EXCEPT ELECTRICAL	534
80	HEALTH SERVICES	91
TOTAL		19,841	2,177

*(1) By survey design, not all 2-digit SICs were surveyed. (2) The estimates for each 2-digit SIC apply only to the 3- and 4-digit SICs surveyed within the 2-digit SIC. Not all SICs were surveyed. (3) When using the estimates, standard errors associated with estimates should be considered. (4) 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.