Toxicity of aerosols of sodium reaction products.

Sodium is used as the heat transfer medium in several new energy technologies such as liquid-metal fast-breeder reactors and solar-thermal collection systems. Because sodium burns in air and reacts violently with water, the potential exists for an airborne release of sodium combustion products and subsequent human exposure. To help evaluate the potential short-term hazard from an accidental sodium fire, male juvenile or adult Wistar rats were exposed to sodium aerosols for 2 hours to determine the dose at which 50 percent of the animals were affected (ED50) for each age group. The estimated ED50 of 510 microgram/l for adults was not significantly different from the estimated ED50 of 489 microgram/l for juveniles. The incidence of acute laryngitis, attributed to exposure, was three times higher for juvenile rats than for adults, and the degree of severity of this lesion was significantly (P less than 0.05) higher for juveniles.