Introduction: In recent years, sodium hydro sulfurous anhydride (Dithionite) has been used as an additive for better preservation, increase of visual appearance and improvement of fermentation action in breads products. The purpose of this study was to determine and quantify the concentration of dithionite in breads produced in Hamadan.

Methods: In this descriptive study, the concentration of Dithionite in bread in breads produced in Hamadan from July to September 2016 was determined. The study population was the whole of active industrial bakeries in the city of Hamadan. The sampling was conducted after listing the bakeries producing bread by referring randomly to the bakeries and taking samples and transmitting them to the laboratory. Finally, the content of dithionite was quantified based on the Iranian National Standard (no: 2628).

Results: The findings indicated that dithionite concentration in all samples in different months was zero, which meets the standard.

Conclusion: The results of this study indicated that dithionite, as an additive, has not been used in processing of the bread; hence, it cannot be considered as a threat to human health.