An inspection of HMP Exeter published in March 2026 found that vulnerable men arriving at the Devon prison were receiving “shocking” standards of care, while ongoing concerns about dangerously high radon gas levels have prompted legal action from current and former prisoners and staff.

What Did the 2026 Inspection Find?

HM Inspectorate of Prisons (HMIP) carried out an unannounced inspection of HMP Exeter between 18 November and 4 December 2025. The resulting report, published on 9 March 2026, painted a picture of a prison where determined leadership and a more stable staff group were beginning to make a difference — but where deep-seated problems continued to put prisoners at risk.

The most serious criticism centred on the treatment of new arrivals. The Chief Inspector found that vulnerable men — including those with mental health conditions, substance dependencies, and those at risk of self-harm — were not receiving adequate support or oversight in their first days and weeks in custody. This initial period is widely recognised by prison health experts as the most dangerous phase of a prison sentence in terms of self-harm and suicide risk.

Inspectors also found that the use of force against prisoners was not being adequately overseen by management, raising concerns about accountability and the consistency of its application. On a more positive note, attendance at education and work activities had improved since the previous inspection, though rates were still considered too low given the size of the prison population.

HMP Exeter is a Category B local and resettlement prison for adult men, located in the city centre of Exeter, Devon. It has a certified capacity of 512 prisoners and opened in 1853, making it one of England’s older Victorian jails. For visitor information, see our dedicated guide to booking a visit to Exeter Prison.

Self-Harm and Deaths in Custody

The rate of self-harm at HMP Exeter was described by inspectors as “too high,” a finding consistent with previous inspections. Of particular gravity is the fact that there have been seven self-inflicted deaths at the prison since the last full inspection in 2022 — a figure that placed Exeter among the worst-performing establishments in the country on this measure.

Inspectors highlighted that prisoners arriving at the jail — particularly those coming directly from court or police custody — were not being identified quickly enough as vulnerable or at risk. Assessments were inconsistent, and the monitoring of those identified as at risk was described as inadequate in a significant number of cases.

The prison’s response to the report acknowledged the seriousness of these findings and committed to a series of improvements to the early days in custody process, including enhanced screening for new arrivals and better coordination between prison staff and NHS healthcare teams operating inside the jail.

Radon Gas at HMP Exeter

Separate from the HMIP inspection, HMP Exeter has been at the centre of a significant public health concern following the disclosure of high radon gas readings through Freedom of Information requests. Radon is a naturally occurring radioactive gas that seeps from granite-rich ground — particularly prevalent in Devon and Cornwall — and is a known cause of lung cancer when exposure is prolonged.

Documents obtained under FOI laws revealed that readings taken on D wing of HMP Exeter in winter 2020 showed a seasonally adjusted result of 2,750 becquerels per cubic metre (Bq/m³) — more than nine times the UK legal action level of 300 Bq/m³. A specialist report commissioned in 2022 recommended that activities and occupancy in the affected areas should be suspended. However, further monitoring at the end of 2024 and into early 2025 still recorded levels above 900 Bq/m³ in some areas of the prison.

HMP Exeter is one of at least 15 to 16 UK prisons where radon levels have been measured above action levels. Other affected establishments include Channings Wood, also in Devon. The Ministry of Justice has stated that radon remediation work is ongoing but has been delayed at some sites while a broader review is conducted across the estate.

Legal Action and Wider Context

Law firm Kesar and Co has been instructed by approximately 20 to 25 current prisoners at HMP Exeter who believe they may have been harmed by prolonged radon exposure, as well as former prisoners and staff from six prisons across England. The firm has stated it is investigating potential claims for personal injury and breach of duty arising from the failure to remediate dangerous radon levels in a timely manner.

Critics have argued that the Ministry of Justice was aware of the problem at Exeter and other prisons for several years before taking comprehensive action, and that prisoners and staff were effectively left exposed to a known carcinogen. Campaigners have drawn parallels with other industrial exposure scandals and called for a formal inquiry into how long radon risk assessments had been suppressed or delayed within the prison estate.

To understand more about the standards prisoners are entitled to expect, read our guide to what prison life in the UK is really like.

What Happens Next?

Following the March 2026 HMIP report, HM Prison and Probation Service is required to produce an action plan addressing the key concerns raised, with clear milestones and accountability measures. HMIP will monitor progress against this plan and may conduct a follow-up inspection if it is not satisfied that improvements are being delivered at pace.

On the radon issue, the MoJ has committed to completing an estate-wide review and publishing its findings. Individual prisons, including Exeter, are expected to submit detailed remediation plans with completion dates. Any prisoners or staff members who believe they have suffered health consequences from radon exposure at HMP Exeter or another UK prison can contact a specialist solicitor or the Prisons and Probation Ombudsman.

If you need to contact HMP Exeter directly, or want to arrange a visit, you can find all contact details including the Exeter Prison telephone number on our site.

Frequently Asked Questions

What did the 2026 inspection of HMP Exeter find?

The March 2026 HMIP report found that vulnerable men arriving at HMP Exeter were not receiving adequate care, self-harm rates were too high, and oversight of use of force was inadequate. Seven self-inflicted deaths had occurred at the prison since the 2022 inspection. Some positive progress was noted, including improved education attendance and more stable staffing.

Is there radon gas at HMP Exeter?

Yes. Freedom of Information disclosures revealed that radon gas levels at HMP Exeter have been measured at more than nine times the legal action level. Levels on D wing in 2020 reached 2,750 Bq/m3, and subsequent monitoring in 2024 and 2025 still recorded elevated readings. The Ministry of Justice has been conducting remediation work, though campaigners argue the response has been too slow.

How many prisons in the UK have dangerous radon levels?

At least 15 to 16 UK prisons have been found to have radon levels above the legal action level of 300 Bq/m3. These include several establishments in Devon and other areas of the country where the underlying geology produces high natural radon emissions. The Ministry of Justice is conducting an estate-wide review and remediation programme.

Can I visit someone at HMP Exeter?

Yes. HMP Exeter accepts social visits on Tuesday, Thursday, Friday, Saturday, and Sunday. Visits must be booked in advance by calling the prison or using the online booking service. Visitors must be on the prisoner approved visitor list. Our full guide to booking a visit to Exeter Prison has all the information you need.

What is HMP Exeter like?

HMP Exeter is a Victorian Category B local and resettlement prison for adult men in the centre of Exeter, Devon, with a capacity of 512. It has faced persistent challenges with self-harm, deaths in custody, and drug use, though inspectors acknowledged that leadership has been working to address these issues. The 2026 inspection found progress in some areas alongside serious ongoing concerns about the treatment of vulnerable new arrivals.