Hydroxylammonium nitrate（HAN） is a major constituent in a class of liquid monopropellants and is extensively used in nuclear industry and space propulsion.Previous toxicological studies have focused on oral

inhalation and dermal routes of exposure to HAN-based propellant blends.In this study

acute and subchronic toxicity of HAN in Wistar rats by intraperitoneal injections were evaluated.In this acute study

doses of HAN at 115

125

135

147

160 or 174 mg/kg were administered.No adverse effects were observed during a 14-day period and at gross histopathological examination.In the subchronic study

HAN at 7

14 or 28 mg/kg were administered for 13 weeks.The treatment with HAN caused significant changes in the weight of spleen

in the level of hematological parameters

total bilirubin

direct bilirubin

uric acid and carbondioxidecombining power and histopathological damages of the lung

liver

spleen and kidney.Overall

the study suggests that 13-week HAN treatment caused abnormal hematological changes and tissue lesions

and the risk of toxicity to mammals is not negligible.