A union reported that maternity workers at NHS trusts had collectively received £735,000 in compensation after being exposed to nitrous oxide at levels above safe thresholds. A settlement covering 121 employees at Basildon Hospital in Essex — among them 85 midwives — brought legal proceedings to a close after the group had raised concerns about tiredness, anxiety, headaches, and cognitive difficulties they linked to gas concentrations that had exceeded regulatory thresholds.
A formal apology to staff was issued by the Mid and South Essex NHS Foundation Trust. Entonox — a gas administered to ease discomfort during labour — sits at the centre of what the Royal College of Midwives has described as the largest collective legal action ever brought by midwives across the UK. Those employees who lodged the complaints had reportedly been taking in the substance across extended periods — in some cases over the course of years — throughout their working hours.
Figures contained in an internal Basildon Hospital document revealed that certain staff members faced exposure readings as much as 30 times above the legally permitted workplace threshold at some point during the 2021–2023 period. For 16 months, those individuals received no notification that testing commissioned by the trust had returned results placing their exposure above permissible safety levels.
The trust reached a settlement over the claims after its workforce was found to have been exposed to elevated concentrations of the gas — a case that a news outlet had first brought to public attention in May. Responsibility for handling legal claims and compensation cases across NHS England sits with NHS Resolution, the body that verified the payouts. A spokesperson confirmed that 121 claims had been resolved, with total payouts reaching £735,000. A handful of additional claims have yet to be resolved.
The Royal College of Midwives noted that one claim in the group had yet to reach a settlement, adding through a spokesperson that no comparable collection of midwife-related claims on this scale had come to their attention before.
Daniel Poet, a solicitor at Thompsons who acted for the workers, told reporters that while his firm was pleased to have obtained compensation on behalf of those affected, the situation should not have arisen at all — noting that the trust had been aware of the hazard from 2021, yet staff received no notification until the year after, and a further year passed before protective measures were put in place. The delay, he argued, should never have been permitted to continue as long as it did.
Gill Walton, the RCM's chief executive and general secretary, noted in a statement that midwives at Basildon had been routinely exposed to nitrous oxide at levels above safe thresholds throughout the period when they were providing care to women and newborns. Knowledge of the fault took over a year to reach the workforce. Calling the settlement among the largest ever won for members, the union's representative argued that no midwife should be subjected to such treatment, and urged NHS employers throughout the country to treat the result as a reason to review how their workforce is managed.
The RCM has additionally contacted every NHS trust across England to outline the hazards posed by the gas, and separately notified the Health and Safety Executive that the trust had not taken adequate steps to address those hazards — a step the organisation described as raising its concerns through the appropriate regulatory channel. Guidance on Entonox use has since been updated and refined through a direct working partnership between the RCM and the HSE.
The trust's chief nursing and quality officer, Louise Crosby, told reporters that the organisation had recognised a need to move more swiftly in dealing with the problems, and that an apology had been extended to staff. The trust noted that the incident had prompted a review of oversight practices, leading to strengthened monitoring of medical gases throughout the maternity unit at Basildon Hospital, the installation of scavenger equipment at that unit, and an assurance that Entonox remains safe for use by women there.
