Effect of sodium hypochlorite on the growth of rats and guinea pigs

Four experiments were conducted with a total of 100 rats and 20 guinea pigs to determine the effects of adding sodium hypochlorite to the drinking water and milk. In three experiments, the liquids were provided ad libitum, but in one it was given by gavage so that the dosage could be expressed in relation to body weight. Available chlorine concentrations ranging between 0 and 2,000 mg/L were tested over periods of 9 days to 6 weeks. Stimulation of growth rate was observed in all experiments with body weight increases of 5.4% to 13.7%. Statistical significance at P less than 0.05 was reached in two experiments. Optimal growth rate was observed with available chlorine concentrations of 20 mg/L in liquids given free choice and at 8 mg/kg of body weight when given by gavage. Toxic effects of the sodium hypochlorite were not observed at any of the concentrations tested below 2,000 mg/L.