The primary purpose of separation is to ensure the protection and safety of persons deprived of their liberty, and the optimal management of prisons. It is also a measure to preserve the principle of the presumption of innocence of untried persons and to provide the most appropriate prison conditions for each category of detainees.
As a matter of principle, women should be separated from men, minors from adults, and untried detainees from convicted detainees. Migrants detained in connection with their migrant status should be separated from convicted persons and held in conditions as far removed from a prison regime as possible. Persons imprisoned for debt and other civil prisoners should be kept separate from persons imprisoned for criminal offenses.
The principle of separation should result in either the existence of units strictly separate from each other within the same facility, or of special institutions for the groups concerned. Separation measures should not lead to restrictions of access to services and care, or to the deterioration of material conditions of detention for the persons concerned.
Other separation criteria can be justified to protect detainees in situations of particular vulnerability due to their age, health condition, ethnicity, sexual orientation, or gender identity. In such cases, separation should not be systematic, should take into account the consent of the persons concerned, and should not amount to solitary confinement or to restrictions in acessing services and cares provided by the institution.