Commissioner may, by order, declare any hospital, to be a penitentiary in respect of any person or class of persons.

https://laws-lois.justice.gc.ca/eng/acts/C-44.6/section-7.html

Penitentiaries

• 7 (1) Subject to subsection (3), the Commissioner may, by order, declare any prison as defined in the Prisons and Reformatories Act, or any hospital, to be a penitentiary in respect of any person or class of persons.

• Marginal note:Idem

  (2) Subject to subsection (3), the Governor in Council may, by order, declare any place to be a penitentiary.

• Marginal note:Provincial approval

  (3) No prison, hospital or place administered or supervised under the authority of an Act of the legislature of a province may be declared a penitentiary under subsection (1) or (2) without the approval of an officer designated by the lieutenant governor of that province.