Household bleaches that contain sodium hypochlorite and sodium hydroxide are the common domestic agents used all around the world, which are frequently accidently ingested by children. Commercial household bleaches are known to have minor adverse effects when ingested, as being mucosal irritants, emetics and weak corrosives. However, our clinical observations of pneumonitis among household bleach ingested by patients without a history of aspiration foretell some possible systemic toxic effects of household bleaches. An experimental study on rats was designed to evaluate systemic effects of household bleaches that contain 4% sodium hypochlorite and less than 0.05% sodium hydroxide on lungs, livers, kidneys and intestines after 2, 4, 6 12, 24 and 48 hours of administration via intragastric route. Prominent congestion and some interstitial mononuclear cellular infiltration were observed in the lungs, the livers and the kidneys of the rats after administration of household bleaches. Additionally, the lungs showed expansion of the alveolar spaces. While erosive changes were present in the stomachs, the intestines were normal. These histopathological changes were especially prominent at early periods of systemic administration. In the second part of the study, to assess whether these findings would hold for intravenous administration of household bleaches, another group of rats were given intravenous administration of household bleach and after 4 hours of intravenous administration of household bleach, the same histopathological changes above were observed in the lungs, kidneys and livers. The study indicates that household bleaches may have systemic effects prominent during early periods of ingestion, although the clinical importance remains to be clarified.