Benzoic acid is a natural food preservative commonly used in milk and dairy products. A study examining preservative levels in domestic and imported cheeses found that, with the exception of cream cheese, no preservatives were detected in domestic soft cheeses or fresh cheeses. In semi-hard cheeses aged for 1–2 months, benzoic acid levels of 2–5 mg/kg were detected. In imported cheeses, only benzoic acid and propionic acid were detected. The average levels of benzoic acid and propionic acid in semi-hard cheeses were 8.73 mg/kg and 18.78 mg/kg, respectively. Specifically, the levels of benzoic acid and propionic acid in soft cheeses were 1.16 mg/kg and 6.80 mg/kg, 3.27 mg/kg and 2.84 mg/kg respectively in fresh cheese, 1.87 mg/kg and not detected in hard cheese, and 2.07 mg/kg and 182.26 mg/kg respectively in processed cheese.