A recently published article in Occupational & Environmental Medicine provides some shocking statistics on the quality of the air in UK National Health Service (NHS) cellular pathology labs. Not only was airborne formaldehyde found to be monitored infrequently in the majority of labs, but concentrations regularly exceeded safety limits defined by the European Union (EU).
The importance of this work was recognized by the Royal College of Pathologists, which honored lead researcher Richard Yates in its annual awards. We spoke to Yates, a histopathology resident at Royal Free London NHS Foundation Trust, to find out more about the study and what needs to change to protect the health of laboratory medical professionals in the NHS.
What first inspired you to investigate formaldehyde exposure in pathology labs?
The US Environmental Protection Agency published its latest risk evaluation for formaldehyde in January 2025, concluding that it presents an "unreasonable risk of injury to human health."
The comprehensive toxicological review found sufficient evidence that formaldehyde inhalation causes cancers of the nose and throat, as well as leukemia. It also found evidence associating formaldehyde inhalation with impaired lung function and allergic airway disease, reduced female fertility, risk of spontaneous abortion, and damage to the nervous system.
Following the report, I became curious about the extent of formaldehyde exposure in NHS pathology departments, where formaldehyde, in the form of formalin, is used every day in large volumes. After a literature search revealed nothing on the topic, I designed a study to address the question, in collaboration with Magdalena Plesa from the University of Liverpool.
How did you approach the study?
Formaldehyde is subject to Control of Substances Hazardous to Health (COSHH) regulations, which require workplaces to conduct a suitable and sufficient risk assessment for all areas in which it is used. This should reasonably involve some degree of monitoring of airborne concentrations.
The Freedom of Information Act allows access to members of the public to environmental monitoring data where it is held by a public body. We asked all the NHS Trusts in England, Scotland, Wales, and Northern Ireland with a cell pathology department documented on their website for their preceding 12 months of airborne monitoring data.
What did you find?
Over 1.7 million results were disclosed by 117 pathology departments over the 12-month study period during 2024-25. The data showed evidence of infrequent monitoring, with 73 percent of sites checking airborne formaldehyde concentrations once weekly or less.
The other key finding was inadequate control. Seventy percent of sites reported airborne formaldehyde concentrations that regularly exceeded the EU safety limit.
Why are these findings important?
The data suggest that pathology lab workers in the NHS are routinely exposed to airborne concentrations of formaldehyde associated with deleterious health effects. Our work therefore raises concern for the thousands of people working in these environments. This now needs to be urgently addressed.
What reforms have you been campaigning for since publication of the study?
The UK has the highest defined formaldehyde work exposure limit in the world. At two parts per million, for both short-term and long-term exposure, the limit is almost seven times higher than in the EU.
Whilst UK workplaces must also reduce exposure to carcinogens to "as low as is reasonably practicable," it is evident from our data that workplaces need to be further incentivized to improve control measures.
We believe, therefore, that the UK workplace exposure limit should be reduced in line with EU standards. This was previously agreed by the UK in 2019, but subsequently abandoned after Brexit. We have also been lobbying for upgraded infrastructure, more regular personal exposure monitoring, better employee education on basic laboratory practice and occupational health risks, improved access to appropriate personal protective equipment, greater management accountability for occupational health, and external oversight by the Health and Safety Executive (HSE).
What is set to change as a result of that lobbying?
The HSE has agreed to work with stakeholders to raise awareness of the appropriate management of exposure to formaldehyde in pathology laboratories. An ongoing HSE investigation will inform a case study demonstrating best practice in the management of formaldehyde. HSE has also committed to providing clearer information for NHS Trusts to help them understand the hierarchy of control as required under COSHH regulations.
As a result of our research, the British Medical Association (BMA) has passed a motion affirming that no doctor should be exposed to hazardous substances while at work. It rules that doctors be removed from workplaces that cannot be shown to be safe with no detriment to pay, training, rota standing, or career progression. Doctors who raise occupational safety concerns should be provided with rapid trade union support as part of the new measures.
The motion also extends to routine environmental monitoring, which, it says, should be transparently shared with doctors. It also affirms that control measures should be properly funded, and exposure limits and workplace controls should be based on the best available evidence. The motion received overwhelming support from the BMA representative body.
Meanwhile, the President of the Royal College of Pathologists (RCPath) has agreed to set up a new working group to advocate for improved working conditions in pathology, with specific reference to formaldehyde exposure.
What other plans do you have for driving awareness of formaldehyde exposure?
We are currently in the process of writing a Best Practice Recommendation for pathology departments on the safe handling of formaldehyde. This will be internally reviewed by RCPath before being put out for public consultation.
We're also working with the NHS Health and Safety Working Group to ensure that the commitments put forward by the HSE are delivered upon. And we'll continue to lobby Members of Parliament and the House of Lords to make sure that the occupational health of NHS staff is not neglected by government.
What is your message to NHS laboratory leaders on protecting the health of staff?
As in any workplace, the productivity of a pathology department will positively correlate with the health and wellbeing of its workers. Given that NHS pathology services underpin so much of NHS care, it is absolutely crucial that we optimize occupational hygiene in labs.
Such changes will, first and foremost, require an acceptance from laboratory leaders that current workplace conditions are, in general, falling well below acceptable standards. Once this is established, we can begin to have a reasonable conversation about improving the infrastructure and governance of over 100 pathology departments throughout the UK.
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