 Rats were fed PhIP "ad libitum" at concentrations of 12.5 and 50ppm.Rats developed mammary tumors at each concentration of PhIP administered.An "in vivo" study found mice injected with 5, 10, 12, 18, 20, 24, 28, 32, or 36 mg/kg bw showed a strong correlation between consumption of PhIP and genetic damage.