Occupational lung diseases associated with the inhalation of dust, chemicals, and proteins cause respiratory ailments. The severity of the disease is related to the material inhaled, the intensity and duration of the exposure. Flour dust is a heterogeneous organic substance can have a tendency to affect lung function. Flour dust in the respiratory tract affects lung function of flour mill workers. Spirometry measures the volume of air an individual inhales or exhales as a function of time to see the assessment of pulmonary function and respiratory disorders caused by organic flour dust in the mill.This is the dynamic lung function test, which rate at which air flows into or out of the lungs. These tests based on time to asses the severity of obstructive and restrictive lung disease.