Working in a Prison Segregation Unit (CSU): Officer Guide 2026

In shortUse support before strain builds up; PSO 1700 says establishments should provide a staff support plan that is not managerial supervision.

Working in a segregation unit can involve prolonged exposure to distress, self-harm, aggression and sometimes the death of someone in your care. If it is affecting you, please use support before it builds up.

Samaritans answers on 116 123, free from any phone at any time; NHS 111 (choose the mental health option in England) can direct you to help; and in an emergency call 999 (checked 3 October 2026).

Inside the service your EAP, Care Team and TRiM practitioners are the services HMPPS says are available after traumatic incidents.

What PSO 1700 says

Working in a segregation unit can place particular demands and challenges on staff, and establishments need to recognise this and develop an appropriate support plan which is not defined as managerial supervision.

In shortA segregation unit, now often called a care and separation unit (CSU), holds prisoners removed from association; it is not a separation centre or a healthcare unit.

A segregation unit holds prisoners who have been removed from association with the main population. Prisoners can be located there for a short period while a situation is managed, while awaiting an adjudication, after a finding of guilt, or for a longer period when no alternative is considered safe.

The PPO describes segregation as an isolating form of custody in which prisoners generally spend most of their time alone in a cell, leaving only to shower, make phone calls and exercise for a short period.

Care and separation unit (CSU)

The name now often used; the IMB report describes CSUs as previously known as segregation units.

Separation centres

A distinct arrangement under the Separation Centre Policy Framework (published 26 July 2022) for specific high-risk prisoners, governed by a different rule. They are not general segregation units.

Healthcare and mental health units

For clinical care. Segregation is not meant to be a substitute for either, a point we return to below.

PSO 1700

The Segregation Policy, the key policy document. We link to the version published on 11 May 2022. The PPO's March 2026 bulletin says the policy is being updated and that there is no published HMPPS data on how many prisoners are segregated, so it is uncertain how often segregation is used or whether its use is increasing. Check your intranet for the version in force in your establishment.

In shortRule 45 allows removal from association for good order or discipline or the prisoner's own interests: 72 hours on the governor's authority, then blocks of up to 14 days, with the Secretary of State's leave beyond 42 days.

• Governor authorisationUp to 72 hoursInitial removal from association
• Further authorisationUp to 14 daysIn writing, in blocks
• Beyond 42 days in totalSecretary of State's leaveNeeded in writing
• Records keptThree yearsThe four records PSO 1700 expects

Rule 45 of the Prison Rules 1999 says that where it appears desirable, for the maintenance of good order or discipline or in the prisoner's own interests, a prisoner may be removed from association.

PSO 1700 says segregation should be used only as a last resort, while keeping a balance so that it remains an option for disruptive prisoners.

The PPO lists four authorised reasons for segregation:

• Good order or discipline.
• The prisoner's own interests.
• Awaiting a disciplinary hearing.
• Following a finding of guilt at a hearing.

In shortPSO 1700 expects competence-based selection, a recommended three-year maximum appointment and specified training; the IMB found units often fall short of the resources to deliver it.

• Recommended maximum appointmentThree yearsReviewed annually; governor can agree longer

PSO 1700 is more specific about staff than many policy documents. Establishments are expected to have a published policy for selecting staff on the basis of competence in dealing with difficult situations and the ability to form constructive relationships with prisoners and encourage reasoned changes in behaviour.

The governor, or the director in a contracted prison, personally endorses each member of staff.

Officers should ideally have completed probation, with an exception where operational needs require otherwise.

• All officers in the unit should be competent in basic control and restraint, including de-escalation and interpersonal-communication skills, delivered by certified trainers.
• Staff should also be competent in race awareness and diversity, mental health awareness and suicide prevention.
• Recommended further courses include the adjudication liaison course, pro-social modelling and basic first aid, including for night staff.
• There should be a published induction policy and a clearly defined line of accountability to the governor.

In shortThe work is behaviour support, observation, record-keeping and handover as much as the physical tasks, with at least three quality history-sheet entries a day per prisoner.

PSO 1700 expects segregation staff to focus on helping prisoners manage their behaviour and problems rather than simply on punishment. That means greater interaction between staff and prisoners, which will alert staff to mental health concerns or self-harm risk, and between segregation and wing staff to plan the prisoner's return.

A designated or personal officer is allocated to each prisoner, who should engage in purposeful dialogue and record at least three quality entries on the segregation history sheet each day.

Practically, there is a lot of handover, record-keeping and watching for change, as well as the physical tasks (exercise, showers, cell cleaning, meals) that the daily log is designed to track.

• Every day: a manager, healthcare and chaplaincy visit the unit.
• At least weekly: the governing governor and Independent Monitoring Board members.
• ACCT case managers visit where a prisoner has an open plan.
• Listeners visit when asked.
• The policy says visits should offer the prisoner a chance to speak confidentially where it is safe.

1. At handover, read the history sheets and the daily memo for each prisoner, including any open ACCT and whether the health screen has been done.
2. Check that the Initial Segregation Health Screen is completed within two hours for any new arrival; if not, make sure the observation levels in PSO 1700 are in place and escalate.
3. Make quality entries on the history sheet for your designated prisoners at least three times a day (morning, afternoon, evening).
4. Keep the daily log up to date for exercise, showers and cell cleans, and record significant events such as use of force or special accommodation in the memo.
5. Escalate concerns about mental health, self-harm or physical health to the supervising officer, healthcare and the ACCT case manager; record who you told and when.
6. Support planning for return to normal location by speaking with wing staff and the prisoner's personal officer.

In shortThe PPO's March 2026 bulletin sets the standard your unit's work will be measured against after a death: exceptional-circumstances-only for prisoners on an ACCT, a two-hour health screen and recorded pathways out.

• Deaths investigated by the PPO6021 April 2024 to 31 December 2025
• In the segregation unit14Of those deaths
• On an open ACCT8Of the 14
• Deaths in custody359In the 12 months to June 2026 (MoJ safety in custody statistics)

The PPO's learning lessons bulletin of March 2026 is the clearest recent statement of what goes wrong. It says:

• Segregation of a prisoner on an ACCT is defensible only in exceptional circumstances, and the duty governor should complete a defensible decision log reflecting risks, triggers and protective factors.
• The initial segregation health screen should be completed within two hours.
• A prisoner's physical health matters as well as mental health.
• Staff should consider and record pathways out of segregation at Segregation Review Boards.

In shortMen with severe mental health conditions wait months in CSUs for a secure hospital bed, and the officers on the unit absorb the pressure of that gap.

• NHS England transfer target28 days14 days from referral to assessment, then a further period to transfer
• IMB: many waitsOver 100 daysFrom start to finish
• IMB: some waitsOver 200 days
• IMB: one waitOver 500 days

The IMB report describes men with severe and complex mental health conditions held in CSUs for long periods because there was nowhere more appropriate for them to go.

For staff, this translates into prolonged care of acutely unwell people in an environment not designed for it. The IMB gave examples:

• Constant supervision being required for much of a prisoner's time in the unit.
• Cells in some CSUs being unsuitable for constant supervision.
• One unit where staff had to carry out 60 observations an hour.
• Special accommodation or anti-ligature clothing used humanely, but the IMB was concerned about how often they were needed.

In shortWe found no HMPPS allowance specific to working in a segregation unit; your pay is your band's pay plus any allowances you are individually entitled to.

• Dirty protest allowance£15 / £30 a dayUp to four hours / more than four hours
• Payment Plus£23.00 an hourAlso the rate for bedwatch and constant watch (PSPRB commentary)
• Operation Tornado£40.00 an hour£30.00 for OSGs

The Prison Service Pay Review Body's 2026 report lists "Separation Centres" among specialist tasks that the POA said staff volunteer for, and says it does not believe a blanket payment for every additional task or specialism is appropriate, while remaining open to evidence about a particular specialism.

Your pay is your band's pay plus any allowances you are individually entitled to; see our pay bands guide and specialist prison roles pay guide.

Some allowances apply where relevant circumstances arise. The tiles show continuing rates from 1 April 2026 in the PSPRB's 2026 table of allowances (Operation Tornado is £40.00 an hour for officers).

In shortIf you are hurt, report to the police, keep records and use the injury, sick pay and ill-health routes in our linked guides.

• Assaults on staff9,833England and Wales, 12 months to March 2026 (MoJ Safety in Custody)
• Of which serious871

Segregation units can involve aggression and the need to use force, and officers do get hurt. If you are injured in an assault, the routes in our assault compensation guide apply. See also the assault statistics guide.

• If you are off work: see the sick pay guide and the free sick pay calculator.
• For longer-term health consequences, the civil service injury benefits guide and the ill-health retirement guide explain the pension-side protections.
• The free ill-health and injury benefit calculator can help you see what these may mean in your situation.