Abstract: The acidified slime generated by titanium dioxide plant was studied to develop the hazardous wastes exemption management research, which could not only reduce the environment risk, but also lighten the load on companies regarding the treatment and disposal of hazardous wastes. The hazardous characteristics identification results showed that the acidified slime did not possess the leaching toxicity for the toxic substances content far lower than the hazardous wastes identification standards, yet it had certain corrosive nature. Rinsing could reduce the corrosivity of acidified slime. After the acidified slime was washed twice, it no longer possessed the hazardous characteristic of corrosivity. Also the leaching toxicity of heavy metals was lowered after the acidified slime was washed. When washed acidified slime was kept in storage, the environmental risk brought up by the surface runoff was not high, and the environmental risk of the acidified slime lowered remarkably after washed. If acidified slime was washed 3 times, it would not cause the pollution risk of water quality even when the geological disasters occurred. The acidified slime generated by titanium dioxide plant could thus be given exemption management after washed.