Some food additives that are commonly used by humans were recently proved to be mutagenic. It is of significant importance to evaluate their genotoxic effects, since they are frequently consumed by humans in their daily meals. In this proposal, we investigated the effects of sodium sulphite, boric acid, and benzoic acid on human cell lines; liver cancer (HepG2), colon cancer (HCT-116), lung cancer (A-459), and normal lung (Wi38) and cells were evaluated using neutral red cytotoxicity assay and assessed using the somatic mutation and recombination test (SMART). These compounds at 100mM concentrations induced tumor induction and increased the frequency compared to a negative control in SMART assay. Also, they reduced the viability of the four examined cell lines cells using different concentrations (75, 150, 300 and 600µg/ml). Boric acid had the highest toxic effect while benzoic had the lowest on the examined cells. The toxicity effect of the tested food additives was higher on normal lung human cells than on lung cancer cells, therefore, these food additives may act as carcinogenic agents