Seven in ten NHS pathology departments across the UK are routinely exposing staff to levels of formaldehyde that exceed European Union workplace safety limits, according to new research published in Occupational & Environmental Medicine. The findings have prompted calls for urgent regulatory reform, with researchers warning that thousands of laboratory workers face a cancer risk that current UK law does not adequately address.

Formaldehyde is widely used in hospital pathology settings to preserve tissue samples ahead of analysis. It is also found in resins, adhesives, disinfectants and some cosmetic products. The International Agency for Research on Cancer classifies it as a Group 1 carcinogen, meaning there is sufficient evidence it causes cancer in humans. Long-term exposure has been linked to nasal tumours and leukaemia in industrial workers, as well as damage to the respiratory, nervous and female reproductive systems. Some researchers have drawn comparisons to asbestos, given the degree to which its risks were historically underestimated in occupational settings.

The study was conducted by researchers from the University of Liverpool and Royal Free London NHS Foundation Trust. Between 2024 and 2025, the team submitted Freedom of Information requests to 122 NHS Trusts, asking for 12 months of formaldehyde airborne monitoring data. All 122 responded, with 104 able to provide complete records covering 117 pathology laboratories across the country. The headline finding was stark: 70 per cent of sites regularly exceeded the EU's long-term workplace exposure limit of 0.3 parts per million over eight hours. Monitoring was also found to be infrequent. Nearly three quarters of sites measured airborne levels once a week or less, 15 per cent did so only quarterly, and four per cent tested just once a year.

The reason no site technically broke the law comes down to a regulatory divergence that followed Brexit. The EU introduced its binding formaldehyde workplace limit in 2021, but the UK, having left the bloc in 2020, was under no obligation to adopt it. The UK's limit, set by the Health and Safety Executive, remains at two parts per million over eight hours, which researchers describe as the highest such threshold in the world. Every site in the study stayed within that figure, meaning employers are legally compliant, even where EU standards are being exceeded by a considerable margin.

For those who have worked in affected environments, the legal technicality offers little comfort. One former NHS laboratory worker described a gradual deterioration in health that began with sore eyes and a runny nose. Over time, he developed nosebleeds and vomiting. After three years working in the role, his breathing had deteriorated to the point where he could no longer continue working.

Academic reaction to the findings has been pointed out. Professor Hans Kromhout of Utrecht University and Dr Martie van Tongeren of Manchester University's Centre for Occupational and Environmental Health co-authored a linked editorial in the same journal. They noted that no common guidelines or standards currently exist for the control and monitoring of formaldehyde across NHS settings, and argued that the evidence presented made the need for such guidelines difficult to ignore.

The NHS said it was aware of the study. "The safety of NHS staff is paramount, and NHS trusts have a duty in law to protect staff from being exposed to hazardous products," mentioned a spokesperson, adding that the organisation was supporting trusts in maintaining safe working environments.

The researchers were unambiguous in their conclusion, calling for national regulatory intervention that would include infrastructure upgrades, more frequent personal exposure monitoring, improved staff training and better access to appropriate protective equipment.

The issue extends beyond the NHS. Formaldehyde exposure is also a recognised concern in construction and other industries across the UK. With the country setting its own regulatory course since leaving the EU, the question of whether workplace safety standards should be realigned with European thresholds is likely to become a recurring one.

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