Have you ever had a biopsy or surgery? Did the doctor take a piece of your flesh out and tell you that they would have to “run some tests on it?” Chances are, that little piece of you went to a pathologist, a doctor who specializes in microscopic medicine. They looked at a slice of you on a slide and decided if you were healthy, and if not, what the diagnosis was.
The first step in processing your sample is to put the tissue in a chemical called formalin, which is a derivative of formaldehyde. Formalin is a toxic chemical that can irritate your eyes, nose, throat and skin. Imagine the worst kind of sterile laboratory smell, extremely strong and unnatural.
The International Agency for Research on Cancer (IARC) has given formaldehyde the highest rating for carcinogenicity in humans. It is a serious concern, as the National Cancer Institute (NCI) has found those exposed to formaldehyde (formalin) are at increased risk of cancers of the nasal passages, blood, bone marrow and brain.
If formalin is so dangerous, why are pathologists and other hospital laboratory employees using it every day? It’s because formalin is very good at “fixing” the tissue sample. In other words, it preserves the structure of the tissue, so it doesn’t rot like a piece of chicken left out for a few days (flesh is flesh, after all). With formalin holding all the structures of the cell in place, the hospital lab can then add special dyes to more easily visualize the sample under the microscope and come to a diagnosis. Many times, the tissue is taken out because there is a concern about cancer. Ironic, no? To diagnose cancer, hospital workers have to expose themselves to a liquid that can cause cancer.
The other big factor is cost. Hospitals don’t just need a Costco-sized shampoo bottle full of formalin to process all their pathology samples in a day, they need many gallons, and formalin is inexpensive to produce or buy in large volumes.
So, what is the solution here? Well, as someone who used to be a pathologist, I can tell you no one is skinny dipping in a vat of formalin, thankfully. To check this dangerous substance so we can get the most use out of it without causing unnecessary harm, there are safety measures in place.
The Occupational Safety and Health Administration (OSHA) sets limits to how much formaldehyde a worker is allowed to be exposed to in a given time period. If you work with formalin, and you are exposed to more than 0.75 parts per million (ppm) over an 8-hour shift, your employer is not following the law. Alternatively, you are allowed to be exposed to up to 2 ppm in a 15-minute period (sometimes, there might be flexibility needed in a workplace, and the government tries to be understanding).
Additionally, there’s also a concept in workplace safety called the hierarchy of controls. These are measures taken, in decreasing order of effectiveness, to make sure workers aren’t being abused. At the top, there’s elimination (can’t hurt you if you’re not around it), substitution (unfortunately, there’s not a realistic option here for formalin), engineering (can you build something to protect people), administrative (those would be the OSHA standards above) or personal protective equipment (PPE) (put on protection to soften the impact).
Stephen Wiesner, an associate professor of Medical Laboratory Sciences at the University of Minnesota Cities, said formalin safety rests on good engineering controls. Examples of this are employees working in fume hoods, keeping the formalin’s source closed off when not using it and disposing of it in a place that is not nearby. There are also air monitors for formaldehyde levels that employees can wear to measure if levels in the air around workplaces are inappropriate. Finally, for PPE, there are gloves, double gloves, goggles, masks and fully body lab suits to avoid clothing contact.
Formalin/Formaldehyde is a dangerous chemical that can cause serious harm in the short and long term. That said, it plays an important role in health care that many patients would be grateful for if they knew about its use. The only way to balance the risk is to make sure these lab workers have all the protections possible in place to stay safe. Since most patients have never seen lab workers, I just want to say thank you for taking on this risk and caring for all of those patients.
Dominik Dabrowski is a student at the University of Minnesota School of Public Health.
