University of Liverpool study finds formaldehyde exposure in NHS cell pathology labs is often monitored too rarely and frequently exceeds EU safety limits

University of Liverpool study finds formaldehyde exposure in NHS cell pathology labs is often monitored too rarely and frequently exceeds EU safety limits

(IN BRIEF) University of Liverpool research has found that formaldehyde exposure in many NHS cell pathology departments is monitored infrequently and often exceeds EU workplace exposure limits, raising concerns about staff safety in laboratory environments where the chemical is widely used. The study, published in BMJ’s Occupational and Environmental Medicine, reviewed 12 months of monitoring data from 117 NHS cell pathology departments and assessed the results using EN 689:2018 standards. Researchers found that 73% of sites measured formaldehyde airborne concentrations once weekly or less, while 70% of sites regularly exceeded the EU long-term workplace exposure limit and 43% regularly exceeded the EU short-term limit. Only 11% of departments combined daily or more frequent monitoring with levels below the EU long-term limit, and only 17% did so for the EU short-term limit. The researchers warned that the findings raise concern for thousands of NHS employees and called for national regulatory intervention, including improved infrastructure, more regular personal exposure monitoring, better staff education, stronger PPE access, management accountability and external oversight by the Health and Safety Executive.

(PRESS RELEASE) LIVERPOOL, 10-Jun-2026 — /EuropaWire/ — University of Liverpool researchers have found that formaldehyde levels in many NHS cell pathology departments are not being monitored often enough and frequently rise above European Union workplace exposure limits, raising concerns over occupational health protections for laboratory staff.

The research, published in BMJ’s *Occupational and Environmental Medicine*, examined formaldehyde airborne monitoring practices across NHS cell pathology departments in the UK. The findings point to gaps in monitoring frequency, workplace controls and occupational hygiene standards, while also highlighting the importance of aligning UK exposure rules more closely with EU standards.

Formaldehyde is widely used in pathology and histology settings, but inhalation exposure has been linked to a wide range of short- and long-term health risks. These include harmful effects on the respiratory system, female reproductive health and the nervous system. Formaldehyde is also classified as a human carcinogen, making regular monitoring and effective workplace safeguards particularly important in laboratory environments where exposure risks can be elevated.

Cell pathology departments are considered among the higher-risk workplaces for formaldehyde inhalation because of the way the chemical is used in the handling and preservation of tissue samples. The researchers said these environments require strong governance, reliable monitoring systems and appropriate infrastructure to protect staff from potentially harmful exposure.

For the study, the research team requested 12 months of formaldehyde monitoring data from 122 NHS Trusts across the UK. The requested data covered monitoring frequency, the number of measurements taken and ranges of airborne formaldehyde concentration. The study then assessed whether the monitoring practices and recorded concentrations met workplace safety expectations, using EN 689:2018 standards for statistical evaluation.

In total, 117 NHS cell pathology departments disclosed 1,715,516 formaldehyde airborne monitoring results. The analysis found that monitoring was generally infrequent, with 73% of sites measuring airborne formaldehyde concentrations once a week or less. Measurements were commonly taken using portable spectrophotometric or electrochemical sensors.

The findings showed that the EU long-term workplace exposure limit was regularly exceeded at 70% of sites, where the 95th percentile was above 0.3 ppm. The EU short-term workplace exposure limit was regularly exceeded at 43% of sites, where the 95th percentile was above 0.6 ppm. The 95th percentile upper tolerance limit also exceeded the EU short-term exposure limit at 68% of sites.

Only a small proportion of departments demonstrated both frequent monitoring and exposure levels below EU limits. The study found that 11% of departments carried out formaldehyde airborne monitoring at least once daily while keeping 95th percentile levels below the EU long-term workplace exposure limit. For the EU short-term limit, 17% of departments achieved frequent monitoring with 95th percentile levels below the threshold.

Dr Magdalena Plesa of the University of Liverpool Management School, the corresponding author of the study, said the data raise concern for thousands of NHS employees working in cell pathology environments. She said urgent national regulatory intervention is needed to improve occupational hygiene across NHS cell pathology departments.

The study was conducted by Dr Plesa in collaboration with Dr Richard Yates of Royal Free London NHS Foundation Trust.

The researchers are calling for national action to strengthen protections for staff working with formaldehyde in NHS pathology settings. They said improvements should include upgraded laboratory infrastructure, more regular personal exposure monitoring, better employee education on laboratory practice and occupational health risks, improved access to suitable personal protective equipment, clearer management accountability for occupational health and external oversight by the Health and Safety Executive.

The study, titled *Under the microscope: formaldehyde exposure in National Health Service pathology departments in the United Kingdom*, was authored by Plesa M. and Yates R.L. and published in *Occupational and Environmental Medicine* in 2026.

Media Contact:

pressoffice@liverpool.ac.uk

SOURCE: University of Liverpool