*(1) The estimates for each occupation apply only to the 3- and 4-digit SICs surveyed within the 2-digit SIC where the agent was observed. Not all SICs were surveyed, and not all agents were observed in all surveyed SICs. (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.