6ROLWDU\FRQILQHPHQWRISULVRQHUV (b) Solitary confinement as a disciplinary sanction Withdrawal of a prisoner from contact with other prisoners may be imposed under the normal disciplinary procedures specified by the law, as the most severe disciplinary punishment. Recognising the inherent dangers of this sanction, countries specify a maximum period for which it may be imposed. This can vary from as little as a few days to as much as a month or more. Some countries allow prison directors to impose a given maximum period, with the possibility for a judicial body to impose a longer period. Most countries – but not all – prohibit sequential sentences of solitary confinement. Given the potentially very damaging effects of solitary confinement, the CPT considers that the principle of proportionality requires that it be used as a disciplinary punishment only in exceptional cases and as a last resort, and for the shortest possible period of time. The trend in many member States of the Council of Europe is towards lowering the maximum possible period of solitary confinement as a punishment. The CPT considers that the maximum period should be no higher than 14 days for a given offence, and preferably lower.11 Further, there should be a prohibition of sequential disciplinary sentences resulting in an uninterrupted period of solitary confinement in excess of the maximum period. Any offences committed by a prisoner which it is felt call for more severe sanctions should be dealt with through the criminal justice system. (c) Administrative solitary confinement for preventative purposes The law in most European countries allows for an administrative decision to place into solitary confinement prisoners who have caused, or are judged likely to cause, serious harm to others or who present a very serious risk to the safety or security of the prison. This may be for as short as a few hours, in the case of an isolated incident, or for as long as a period of years in cases involving prisoners who are considered as particularly dangerous and to continue to pose an imminent threat. This is potentially the longest lasting type of solitary confinement and often the one with the fewest procedural safeguards. It is therefore crucial that there be rules to ensure that it is not used too readily (e.g. as an immediate response to every disciplinary infraction pending adjudication), too extensively or for too lengthy periods. Accordingly, the safeguards described in paragraph 57 below must be rigorously followed. 11. The maximum period should certainly be lower in respect of juveniles.