Does consuming sodium benzoate (preservative E211) cause problems during pregnancy?

Question

There seems to be strong evidence to support the claim that sodium benzoate (E211) causes hyperactivity in young children, e.g. Bateman et al. (2004) and McCann et al. (2007). This leads me to consider whether or not E211 is harmful during pregnancy.

A study by Mowafy et al. (2001) found a slight decrease in survival rates for pups of pregnant rats given sodium benzoate; they also found a more significant drop in mean weight of their pups.

Question: Could the consumption of sodium benzoate by the mother be harmful during human pregnancy? How would this be the case?

References:

• Bateman, B., Warner, J.O., Hutchinson, E., Dean, T., Rowlandson, P., Gant, C., Grundy, J., Fitzgerald, C. & Stevenson, J. (2004) The effects of a double blind, placebo controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of preschool children. Archives of Disease in Childhood. [Online] 89 (6), 506 –511.
• McCann, D., Barrett, A., Cooper, A., Crumpler, D., Dalen, L., Grimshaw, K., Kitchin, E., Lok, K., Porteous, L., Prince, E., Sonuga-Barke, E., Warner, J.O. & Stevenson, J. (2007) Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. The Lancet. [Online] 370 (9598), 1560–1567.
• Mowafy, A.R., Darwish, A.M., El-Kholy, S.A. & Abdel-Mohsen, S.H. (2001) Effect of food preservatives on mother rats and survival of their offspring. The Journal of the Egyptian Public Health Association. 76 (3-4), 281–295.

Answer 1

There is some evidence to support the idea that sodium benzoate may be detrimental to the development of the foetus:

TERATOGENIC EFFECTS: Classified POSSIBLE for human.

DEVELOPMENTAL TOXICITY: Classified Reproductive system/toxin/female, Reproductive system/ toxin/male [SUSPECTED].

^{MSDS for Sodium Benzoate}

This has been shown experimentally in rats by Minor & Becker in 1971. They introduced high doses of up to 1000 mgkg^-1 intraperitoneally and recorded reduction in foetal weight and "gross anomalies". Whilst I struggled to find a copy of their original paper, it is referenced in the Catalog of Teratogenic Agents¹ (Thomas H. Shepard).

There is some evidence to refute this, however. The Acceptable Daily Intake limits on sodium benzoate is a maximum of 5mgkg^-1, at this dose there is no noticeable effect of exposure. ^(2,3) The latter paper by EC food safety standards goes further:

There appear to be sufficient studies to conclude absence of teratogenic potential, with an overall NOAEL* for developmental toxicity of 500 mg/kg bw/day, based on effects on fetal weight.

*(No observed adverse effect level)

So the consensus from the food safety bodies suggests that E211 should not pose harm to an unborn child in the quantities allowed to be present as an additive.

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1 Emire, Ronald J. "306: Benzoate, Sodium." Catalog of Teratogenic Agents. By Thomas H. Shepherd. JHU, 2004. 44-45. Google Books. Google. Web. 10 Feb. 2012.

2 Nair, B. "Final Report on the Safety Assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate." International Journal of Toxicology 20.3 (2001). International Journal of Toxicology. Web. 10 Feb. 2012.

3 Scientific Committee on Food. Opinion of the Scientific Committee on Food on Benzoic acid and its salts. Rep. 24 Sept. 2002. EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL. 10 Feb. 2012