In the pulp and paper industry, intense operator activity has been demonstrated to cause fatigue in bleachers and chlorinators at different times of shift work (day, evening, and night). In all the operators, the tests for sensorimotor coordination revealed an increase in the number of errors and changes in the index of coordination; in addition, in chlorinators, fatigue was accompanied by feeling unwell and low activity (the WAM test). The diurnal rhythm of physiological functions against the background of work activity was determined from changes in the body temperature (in bleachers), heart rate, blood pressure, and sensorimotor coordination. The presence of harmful chemical substances (chlorine and chlorine dioxide) in the air negatively influenced the psychophysiological state of the chlorinators.