Millipedes are not poisonous, but some species produce fluids that may cause allergic reactions in some people. The fluids may contain hydrochloric acid, which can react on the skin and cause long-term discoloration.
Handling a millipede with a person's hands is not advisable, as it may release fluid onto the person's skin. Some species are capable of spraying the fluid several inches. The fluid released by a millipede usually has a bad odor, and a person may need to scrub the area thoroughly with soap to get rid of the odor. A person can use alcohol or ether to get rid of the fluid.