(1)    The department may, by rule, prohibit particular methods of treatment or disposal of particular hazardous wastes, upon a finding that restrictions on treatment or disposal methods are necessary to protect public health and safety or the environment.

   (2)   The department may exempt by rule any person who generates, transports, treats, stores or disposes of hazardous wastes from any provision under this chapter or from any rule promulgated under this chapter if the generation, transportation, treatment, storage or disposal does not present a significant hazard to public health and safety or the environment.

   (3)   The department may promulgate rules which specify the duration of licenses issued under s. 291.25.