IDENTIFICATION AND USE: Sodium benzoate is a colorless crystalline powder. It is used as food preservative, antiseptic, medicine, in tobacco, in pharmaceutical preparations, as an intermediate for manufacture of dyes, and as a rust and mildew inhibitor.
HUMAN EXPOSURE AND TOXICITY: In a study with 2045 patients of dermatological clinics, only 5 persons (approximately 0.2%) showed a positive reaction in patch tests, while 34 of 5202 patients (approximately 0.7%) with contact urticaria reacted positively. Cases of urticaria, asthma, rhinitis, or anaphylactic shock have been reported following oral, dermal, or inhalation exposure to sodium benzoate. The symptoms appear shortly after exposure and disappear within a few hours. Chromosome aberration test was carried out on sodium benzoate using human embryonic lung culture cells. Sodium benzoate produced no significant increase in the aberration frequency in the anaphase chromosomes when tested at the dosage levels 0, 2.0 ug/mL, 20 ug/mL and 200 g/mL. In human embryonic lung cells (WI-38) treated with sodium benzoate both chromosome abnormalities and mitotic indices were within normal values. Sodium benzoate was mutagenic and cytotoxic in lymphocytes, where it caused micronucleus formation and chromosome break.
ANIMAL STUDIES: An acute dermal irritation/corrosion study gave no indication for skin irritating effect in rabbits. Sodium benzoate was only slightly irritating to the eye. In a 90-day study with rats dosed with 0, 1, 2, 4, or 8% sodium benzoate via diet, the mortality in the highest dose group (approx. 6290 mg/kg body weight per day) was about 50%. Other effects in this group included a reduced weight gain, increased relative weights of liver and kidneys, and pathological changes in these organs. Sodium benzoate was given in drinking water to 50 female and 50 male mice from weeks 5 on for lifespan. The average daily intake of sodium benzoate was 119.2 mg for a female and 124.0 mg for a male (approx. 5.95 - 6.2 g/kg bw/d). There was no effect on the survival of the treated mice when compared with the untreated control. There were no significant differences between the tumor distribution in sodium benzoate-treated and untreated control mice. In a developmental study rats were injected intraperitoneally with 100, 315, or 1000 mg/kg sodium benzoate on gestation days 9 to 11 or 12 to 14. Reduced fetal body weight, increased in utero deaths (by 12%), and gross anomalies were noted at the highest dose. No evidence of teratogenicity was noted in rats administered 510 mg/kg of sodium benzoate by gavage on gestation days 9 to 11. Sodium benzoate (up to 3.0 mg/plate) was tested in the Salmonella/microsome test using S. typhimurium TA 92, TA 94, TA 98, TA 100, TA 1535 and TA 1537. No significant increases in the numbers of revertant colonies were detected in any S. typhimurium strains at the maximum dose. Sodium benzoate tested negative in a cytogenetic assay (bone marrow) in rats after single or multiple oral application of doses up to 5000 mg/kg body weight. In a study with mice, there was also no indication of mutagenic activity in a host-mediated assay. |