The oral and intraperitoneal (i.p.) toxicities to female BALB/c mice of ricin and abrin in phosphate-buffered saline (PBS), spring water, apple juice, and half-and-half (only oral) were examined after brief (2 h) and prolonged (11 to 13 days) storage. The ricin and abrin samples prepared in PBS had oral toxicities consistent with those previous studies, indicating oral and i.p. 50% lethal doses of > 1 mg/kg of body weight and between 2 and 20 microg/kg of body weight, respectively. The toxicities of ricin and abrin in PBS were greater than those in apple juice and water. The oral toxicity of ricin and abrin in half-and-half appeared comparable to or less than that observed for the toxins in water. Spiked samples stored for a maximum of 11 days (13 for the abrin samples) at 4 degrees C induced similar numbers of fatalities as did samples stored for only 2 h. Enzyme-linked immunosorbent assays of the samples administered by i.p. injection indicated a decrease in detectable toxin at 0.5 microg/ml.