Final Report on the Safety Assessment of Sodium Sulfate I

Sodium Sulfate is used as a viscosity increasing agent in cosmetic formulations, at concentrations that are reportedly as high as 97%. No evidence of systemic taxicity was seen in oral exposure studies in animals, although there was moderate ocular irritation in rabbits when a granular sodium carbonate-Sodium Sulfate mixture was instilled. No developmental or reproductive toxicity was reported in rats or mice; there was an increase in birth weight in the mice. Sodium Sulfate was negative in mutagenesis assays. In several studies in which Sodium Sulfate was given with other agents, the results depended on the carcinogenicity of the other agents. Clinical data indicated no significant adverse effects following dermal, oral, or inhalation exposure. Because some irritation was seen under patch test conditions, it was concluded that the concentration should be limited to a level known to produce only a very small frequency of irritation if used in a leave-on application. Accordingly, Sodium Sulfate was found to be safe for use in rinse-off formulations, and safe at concentrations up to 1% in leave-on formulations.