There is increasing concern about transient exposure in disaster and emergency. However, conventional toxicology testing methods may not address this situation. Thus, we assessed the toxic effects of a history of transient exposure in childhood stages by exposing male rats to tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) at their neonatal and adult stages. Rats receiving TDCIPP on both stages had significantly increased adrenal gland weight compared with rats receiving TDCIPP at adult stage only.