Abstract
A method involving classification of employee job tasks into exposure zones is proposed to guide the industrial hygienist in assigning personal samples to employees in a facility. Workers are assigned to an exposure zone on the basis of similar profiles of chemical exposures, ventilation characteristics, and job tasks. Two facilities are used to illustrate the power of the exposure zone method to reduce the number of required samples while increasing the confidence of identifying workers at high risk. Details of the zoning and calculation procedures are described in detail.